Category: News
Gradient descent with a simple function
Hi everyone, I am currently practicing this method on a simple function, however I keep getting this error and I do not know how to fix it.
Here is my programe:
fplot(@(x)myfun(x),[-10,10]);
alpha = 0.01;
x0 = -5;
% ——-using GD———————-
[x grad] = gradient(alpha,x0)
% hold on
% figure;
fprintf(‘x = %fn’,x);
fprintf(‘grad = %fn’,grad);
% ——————————
function f = myfun(x)
f = x^2+5*sin(x);
end
function [x,grad] = gradient(alpha,x0)
grad = 2*x0+5*cos(x0);
x = x0;
for i = 0:50
x = x – alpha*grad;
if abs(grad(x))< 0.01
break
display(x);
% grad = grad(x);
end
end
Here is the error that I got
Array indices must be positive integers or logical values.
Error in gradient (line 6)
if abs(grad(x))< 0.01
Error in Gradient_descent_1 (line 5)
[x grad] = gradient(alpha,x0)Hi everyone, I am currently practicing this method on a simple function, however I keep getting this error and I do not know how to fix it.
Here is my programe:
fplot(@(x)myfun(x),[-10,10]);
alpha = 0.01;
x0 = -5;
% ——-using GD———————-
[x grad] = gradient(alpha,x0)
% hold on
% figure;
fprintf(‘x = %fn’,x);
fprintf(‘grad = %fn’,grad);
% ——————————
function f = myfun(x)
f = x^2+5*sin(x);
end
function [x,grad] = gradient(alpha,x0)
grad = 2*x0+5*cos(x0);
x = x0;
for i = 0:50
x = x – alpha*grad;
if abs(grad(x))< 0.01
break
display(x);
% grad = grad(x);
end
end
Here is the error that I got
Array indices must be positive integers or logical values.
Error in gradient (line 6)
if abs(grad(x))< 0.01
Error in Gradient_descent_1 (line 5)
[x grad] = gradient(alpha,x0) Hi everyone, I am currently practicing this method on a simple function, however I keep getting this error and I do not know how to fix it.
Here is my programe:
fplot(@(x)myfun(x),[-10,10]);
alpha = 0.01;
x0 = -5;
% ——-using GD———————-
[x grad] = gradient(alpha,x0)
% hold on
% figure;
fprintf(‘x = %fn’,x);
fprintf(‘grad = %fn’,grad);
% ——————————
function f = myfun(x)
f = x^2+5*sin(x);
end
function [x,grad] = gradient(alpha,x0)
grad = 2*x0+5*cos(x0);
x = x0;
for i = 0:50
x = x – alpha*grad;
if abs(grad(x))< 0.01
break
display(x);
% grad = grad(x);
end
end
Here is the error that I got
Array indices must be positive integers or logical values.
Error in gradient (line 6)
if abs(grad(x))< 0.01
Error in Gradient_descent_1 (line 5)
[x grad] = gradient(alpha,x0) machine learning MATLAB Answers — New Questions
Create an index based Schmitt Trigger
Hello, I have a function that mimics a Schmitt Trigger to translate an analog sine wave into a digital square wave. So far, I have accomplished this with a for loop and the function works as planned. However, since I have a significant amount of data to process, I would like to do this index based for speed. I cannot think of a way to make this index based so the function performes faster.
My function is below, any suggestions on how to make this index based? Is it possible?
Thanks.
function [y] = Schmitt_Trigger(x,tL,tH)
%x is the input array that contains the analog sine wave to process.
%tL is the lower bound of the hysteresis and tH is the upper bound.
N = length(x);
y = zeros(1,N);
for i = 2:N
y(i) = y(i-1);
if y(i-1) == 0 && x(i)>tH
y(i) = 1;
end
if y(i-1) == 1 && x(i)<tL
y(i) = 0;
end
end
endHello, I have a function that mimics a Schmitt Trigger to translate an analog sine wave into a digital square wave. So far, I have accomplished this with a for loop and the function works as planned. However, since I have a significant amount of data to process, I would like to do this index based for speed. I cannot think of a way to make this index based so the function performes faster.
My function is below, any suggestions on how to make this index based? Is it possible?
Thanks.
function [y] = Schmitt_Trigger(x,tL,tH)
%x is the input array that contains the analog sine wave to process.
%tL is the lower bound of the hysteresis and tH is the upper bound.
N = length(x);
y = zeros(1,N);
for i = 2:N
y(i) = y(i-1);
if y(i-1) == 0 && x(i)>tH
y(i) = 1;
end
if y(i-1) == 1 && x(i)<tL
y(i) = 0;
end
end
end Hello, I have a function that mimics a Schmitt Trigger to translate an analog sine wave into a digital square wave. So far, I have accomplished this with a for loop and the function works as planned. However, since I have a significant amount of data to process, I would like to do this index based for speed. I cannot think of a way to make this index based so the function performes faster.
My function is below, any suggestions on how to make this index based? Is it possible?
Thanks.
function [y] = Schmitt_Trigger(x,tL,tH)
%x is the input array that contains the analog sine wave to process.
%tL is the lower bound of the hysteresis and tH is the upper bound.
N = length(x);
y = zeros(1,N);
for i = 2:N
y(i) = y(i-1);
if y(i-1) == 0 && x(i)>tH
y(i) = 1;
end
if y(i-1) == 1 && x(i)<tL
y(i) = 0;
end
end
end matlab, schmitt trigger, speed, index based MATLAB Answers — New Questions
Motion analysis in captured video
I have a camera mounted on a car capturing video. The car starts and stops frequently. I want to figure out when the car stops and starts. There is enough disturbance in the environment with uneven ground and even a breeze can cause huge changes in the environment. Just looking for difference from frame to frame does not give me what I need. I have tried that already. There are no markers either to distinguish when the car stops. This is not inline analysis. I have to do this offline.
Any ideas to try would be greatly appreciated.I have a camera mounted on a car capturing video. The car starts and stops frequently. I want to figure out when the car stops and starts. There is enough disturbance in the environment with uneven ground and even a breeze can cause huge changes in the environment. Just looking for difference from frame to frame does not give me what I need. I have tried that already. There are no markers either to distinguish when the car stops. This is not inline analysis. I have to do this offline.
Any ideas to try would be greatly appreciated. I have a camera mounted on a car capturing video. The car starts and stops frequently. I want to figure out when the car stops and starts. There is enough disturbance in the environment with uneven ground and even a breeze can cause huge changes in the environment. Just looking for difference from frame to frame does not give me what I need. I have tried that already. There are no markers either to distinguish when the car stops. This is not inline analysis. I have to do this offline.
Any ideas to try would be greatly appreciated. motion, image analysis, image processing, video analysis MATLAB Answers — New Questions
Microsoft Media Foundation while using audioread
Hi,
I have a brand new PC at my lab where Windows 10 Pro Education N (Version 10.0 (Build 19042)) is installed. I already checked for every update and Windows Update says all is updated, however I’m getting the following error on Matlab (9.5.0.1586782 (R2018b) Update 8):
"Error using audioread (line 104)
Audio file I/O requires Microsoft(R) Media Foundation.
Install this on your system and restart MATLAB."
I already searched for the Microsoft Media Foundation installer and I’m getting an error saying that the PC is incompatible with that installation. I believe that is due to the fact that the PC is already updated according to what I found on the internet.
Does anybody know a permanent solution for this? I know I probably should contact to my university IT department since computer’s updates are linked to the university, but first I wanted to ask here since you know better how to deal with Matlab.
Thanks in advance,
Javi.Hi,
I have a brand new PC at my lab where Windows 10 Pro Education N (Version 10.0 (Build 19042)) is installed. I already checked for every update and Windows Update says all is updated, however I’m getting the following error on Matlab (9.5.0.1586782 (R2018b) Update 8):
"Error using audioread (line 104)
Audio file I/O requires Microsoft(R) Media Foundation.
Install this on your system and restart MATLAB."
I already searched for the Microsoft Media Foundation installer and I’m getting an error saying that the PC is incompatible with that installation. I believe that is due to the fact that the PC is already updated according to what I found on the internet.
Does anybody know a permanent solution for this? I know I probably should contact to my university IT department since computer’s updates are linked to the university, but first I wanted to ask here since you know better how to deal with Matlab.
Thanks in advance,
Javi. Hi,
I have a brand new PC at my lab where Windows 10 Pro Education N (Version 10.0 (Build 19042)) is installed. I already checked for every update and Windows Update says all is updated, however I’m getting the following error on Matlab (9.5.0.1586782 (R2018b) Update 8):
"Error using audioread (line 104)
Audio file I/O requires Microsoft(R) Media Foundation.
Install this on your system and restart MATLAB."
I already searched for the Microsoft Media Foundation installer and I’m getting an error saying that the PC is incompatible with that installation. I believe that is due to the fact that the PC is already updated according to what I found on the internet.
Does anybody know a permanent solution for this? I know I probably should contact to my university IT department since computer’s updates are linked to the university, but first I wanted to ask here since you know better how to deal with Matlab.
Thanks in advance,
Javi. microsoft media foundation, microsoft, media foundation, audioread error MATLAB Answers — New Questions
Why can’t i draw pcolor() plots anymore with Matlab 2025a?
Hi, i recently upgraded from 2021b to 2025a and now the canvas of my figure is white and Matlab throws the warning:
Warning: An error occurred while drawing the scene: Error in web draw traversal: RangeError: Array buffer allocation failed
For better understanding:
I call the pcolor() function and the figure out of a Matlab app. Plotting that into the UIAxes in Matlab 2021b gave me the same error. My workaround was to create a standard figure and plot into this. Now with Matlab 2025a, i do not have this workaround anymore and i get the same error either way.Hi, i recently upgraded from 2021b to 2025a and now the canvas of my figure is white and Matlab throws the warning:
Warning: An error occurred while drawing the scene: Error in web draw traversal: RangeError: Array buffer allocation failed
For better understanding:
I call the pcolor() function and the figure out of a Matlab app. Plotting that into the UIAxes in Matlab 2021b gave me the same error. My workaround was to create a standard figure and plot into this. Now with Matlab 2025a, i do not have this workaround anymore and i get the same error either way. Hi, i recently upgraded from 2021b to 2025a and now the canvas of my figure is white and Matlab throws the warning:
Warning: An error occurred while drawing the scene: Error in web draw traversal: RangeError: Array buffer allocation failed
For better understanding:
I call the pcolor() function and the figure out of a Matlab app. Plotting that into the UIAxes in Matlab 2021b gave me the same error. My workaround was to create a standard figure and plot into this. Now with Matlab 2025a, i do not have this workaround anymore and i get the same error either way. figure MATLAB Answers — New Questions
Question about entry-wise product of general plant and weighting function matrix using Hinfstruct for multi-objective design
When I obtained the transfer matrix T from exogenous input w to real (unweighted) output z, entrywise product of matrix T and weighted transfer function matrix W is expected to be calculated and optimized. I use connect command to obtain T, which is a 4*2 transfer function matrix with adjustable parameters, reflecting the tranfer relation from input w=[Pref, wg]’ to output z=[Pref-p, p, wu, q+V/Dq]’. W is a constant transfer function matrix. Direct entrywise product of T and W cannot be implemented with MATLAB. As mentioned in P. Apkarian’s paper "Structured Hinfinity Synthesis in MATLAB", it should be formulated as Standard Form like H=blkdiag(Tij*Wij), then "Hinfstruct" can be used on H to find the tuned controllers. So I use the command like this:
H=blkdiag(T(1,1)*W11, T(1,2)*W12, T(2,1)*W21, T(2,2)*W22, T(3,1)*W31, T(3,2)*W32, T(4,1)*W41, T(4,2)*W42);
T = hinfstruct(H,opt);
However, above code cannot get the correct results. The reason I think should be the increased system order. For example, original system T has only 12 states. But system H has 103 states, where 7 states are from weighting fucntions, and the remaining 96 states are the 8 repeated states of system T, that is, 12*8=96.
Take a more realistic case with official Matlab’s "hinfstruct" example as follows. The goal is to minimize the H-infinity norm from [r, nw]’ to [y, ew]’. An important difference is that there is no entrywise product of Tij and Wij. It means the goal is to minimize 4 transfer functions: T(y,r), T(y,nw), T(ew,r), T(ew,nw).
The official command is given as follows, which works well:
T0 = connect(G,Wn,We,C0,F0,Sum1,Sum2,{‘r’,’nw’},{‘y’,’ew’});
T = hinfstruct(T0);
If I want to formulate the above 4 optimization goals T(y,r), T(y,nw), T(ew,r), T(ew,nw) into Standard From (diagnol form), I revise the above code as follows:
T0 = connect(G,Wn,We,C0,F0,Sum1,Sum2,{‘r’,’nw’},{‘y’,’ew’});
T0_revised = blkdiag(T0(1,1),T0(1,2),T0(2,1),T0(2,2));
T = hinfstruct(T0_revised);
It also cannot operate correctly. Only revise it as follows can work:
T0 = connect(G,Wn,We,C0,F0,Sum1,Sum2,{‘r’,’nw’},{‘y’,’ew’});
T0_revised=blkdiag(1,LS)*T0*blkdiag(1,1/LS);
T = hinfstruct(T0_revised,opt);
But it is still not the entry-wise product case, just the traditonal single transfer function connection as shown in the above figure.
Therefore, could you share your idea about this solution then I can learn based on it, and further do more improvement. I am looking forward to your reply. Thanks a lot for your help!When I obtained the transfer matrix T from exogenous input w to real (unweighted) output z, entrywise product of matrix T and weighted transfer function matrix W is expected to be calculated and optimized. I use connect command to obtain T, which is a 4*2 transfer function matrix with adjustable parameters, reflecting the tranfer relation from input w=[Pref, wg]’ to output z=[Pref-p, p, wu, q+V/Dq]’. W is a constant transfer function matrix. Direct entrywise product of T and W cannot be implemented with MATLAB. As mentioned in P. Apkarian’s paper "Structured Hinfinity Synthesis in MATLAB", it should be formulated as Standard Form like H=blkdiag(Tij*Wij), then "Hinfstruct" can be used on H to find the tuned controllers. So I use the command like this:
H=blkdiag(T(1,1)*W11, T(1,2)*W12, T(2,1)*W21, T(2,2)*W22, T(3,1)*W31, T(3,2)*W32, T(4,1)*W41, T(4,2)*W42);
T = hinfstruct(H,opt);
However, above code cannot get the correct results. The reason I think should be the increased system order. For example, original system T has only 12 states. But system H has 103 states, where 7 states are from weighting fucntions, and the remaining 96 states are the 8 repeated states of system T, that is, 12*8=96.
Take a more realistic case with official Matlab’s "hinfstruct" example as follows. The goal is to minimize the H-infinity norm from [r, nw]’ to [y, ew]’. An important difference is that there is no entrywise product of Tij and Wij. It means the goal is to minimize 4 transfer functions: T(y,r), T(y,nw), T(ew,r), T(ew,nw).
The official command is given as follows, which works well:
T0 = connect(G,Wn,We,C0,F0,Sum1,Sum2,{‘r’,’nw’},{‘y’,’ew’});
T = hinfstruct(T0);
If I want to formulate the above 4 optimization goals T(y,r), T(y,nw), T(ew,r), T(ew,nw) into Standard From (diagnol form), I revise the above code as follows:
T0 = connect(G,Wn,We,C0,F0,Sum1,Sum2,{‘r’,’nw’},{‘y’,’ew’});
T0_revised = blkdiag(T0(1,1),T0(1,2),T0(2,1),T0(2,2));
T = hinfstruct(T0_revised);
It also cannot operate correctly. Only revise it as follows can work:
T0 = connect(G,Wn,We,C0,F0,Sum1,Sum2,{‘r’,’nw’},{‘y’,’ew’});
T0_revised=blkdiag(1,LS)*T0*blkdiag(1,1/LS);
T = hinfstruct(T0_revised,opt);
But it is still not the entry-wise product case, just the traditonal single transfer function connection as shown in the above figure.
Therefore, could you share your idea about this solution then I can learn based on it, and further do more improvement. I am looking forward to your reply. Thanks a lot for your help! When I obtained the transfer matrix T from exogenous input w to real (unweighted) output z, entrywise product of matrix T and weighted transfer function matrix W is expected to be calculated and optimized. I use connect command to obtain T, which is a 4*2 transfer function matrix with adjustable parameters, reflecting the tranfer relation from input w=[Pref, wg]’ to output z=[Pref-p, p, wu, q+V/Dq]’. W is a constant transfer function matrix. Direct entrywise product of T and W cannot be implemented with MATLAB. As mentioned in P. Apkarian’s paper "Structured Hinfinity Synthesis in MATLAB", it should be formulated as Standard Form like H=blkdiag(Tij*Wij), then "Hinfstruct" can be used on H to find the tuned controllers. So I use the command like this:
H=blkdiag(T(1,1)*W11, T(1,2)*W12, T(2,1)*W21, T(2,2)*W22, T(3,1)*W31, T(3,2)*W32, T(4,1)*W41, T(4,2)*W42);
T = hinfstruct(H,opt);
However, above code cannot get the correct results. The reason I think should be the increased system order. For example, original system T has only 12 states. But system H has 103 states, where 7 states are from weighting fucntions, and the remaining 96 states are the 8 repeated states of system T, that is, 12*8=96.
Take a more realistic case with official Matlab’s "hinfstruct" example as follows. The goal is to minimize the H-infinity norm from [r, nw]’ to [y, ew]’. An important difference is that there is no entrywise product of Tij and Wij. It means the goal is to minimize 4 transfer functions: T(y,r), T(y,nw), T(ew,r), T(ew,nw).
The official command is given as follows, which works well:
T0 = connect(G,Wn,We,C0,F0,Sum1,Sum2,{‘r’,’nw’},{‘y’,’ew’});
T = hinfstruct(T0);
If I want to formulate the above 4 optimization goals T(y,r), T(y,nw), T(ew,r), T(ew,nw) into Standard From (diagnol form), I revise the above code as follows:
T0 = connect(G,Wn,We,C0,F0,Sum1,Sum2,{‘r’,’nw’},{‘y’,’ew’});
T0_revised = blkdiag(T0(1,1),T0(1,2),T0(2,1),T0(2,2));
T = hinfstruct(T0_revised);
It also cannot operate correctly. Only revise it as follows can work:
T0 = connect(G,Wn,We,C0,F0,Sum1,Sum2,{‘r’,’nw’},{‘y’,’ew’});
T0_revised=blkdiag(1,LS)*T0*blkdiag(1,1/LS);
T = hinfstruct(T0_revised,opt);
But it is still not the entry-wise product case, just the traditonal single transfer function connection as shown in the above figure.
Therefore, could you share your idea about this solution then I can learn based on it, and further do more improvement. I am looking forward to your reply. Thanks a lot for your help! hinfstruct, robust control, control system toolbox MATLAB Answers — New Questions
Variable might be set by a nonscalar (three variables in pythagorean triplet)
Hi everyone,
Im working for project euler and I try to do #9 (Special Pythagorean Triplet). I have encountered couples of errors, one of which is something that occurs from my trying to make 3 arrays probably, some of them are named Variable might be set by a nonscalar and other errors which I don’t understand.
function y = pythtrip(a,b,c)
%UNTITLED Summary of this function goes here
% Detailed explanation goes here
y = a*b*c;
a = 0:750;
b = 0:750;
c = 0:750;
while (a>b) && b>c && (a^2)+(b^2)==(c^2) && a+b+c == 1000;
pythtrip(a,b,c)
y;
endHi everyone,
Im working for project euler and I try to do #9 (Special Pythagorean Triplet). I have encountered couples of errors, one of which is something that occurs from my trying to make 3 arrays probably, some of them are named Variable might be set by a nonscalar and other errors which I don’t understand.
function y = pythtrip(a,b,c)
%UNTITLED Summary of this function goes here
% Detailed explanation goes here
y = a*b*c;
a = 0:750;
b = 0:750;
c = 0:750;
while (a>b) && b>c && (a^2)+(b^2)==(c^2) && a+b+c == 1000;
pythtrip(a,b,c)
y;
end Hi everyone,
Im working for project euler and I try to do #9 (Special Pythagorean Triplet). I have encountered couples of errors, one of which is something that occurs from my trying to make 3 arrays probably, some of them are named Variable might be set by a nonscalar and other errors which I don’t understand.
function y = pythtrip(a,b,c)
%UNTITLED Summary of this function goes here
% Detailed explanation goes here
y = a*b*c;
a = 0:750;
b = 0:750;
c = 0:750;
while (a>b) && b>c && (a^2)+(b^2)==(c^2) && a+b+c == 1000;
pythtrip(a,b,c)
y;
end project_euler, pythagorean triplet, arrays, while loop, function MATLAB Answers — New Questions
Trying to determine locations of markers in image
I’m trying to obtain the pixel coordinates of the dot pattern image data that is stored in the attached file; I’m using this image to spatially calibrate my camera image. Is there a way to automate the detection of these dots? Thanks in advance for any guidance.I’m trying to obtain the pixel coordinates of the dot pattern image data that is stored in the attached file; I’m using this image to spatially calibrate my camera image. Is there a way to automate the detection of these dots? Thanks in advance for any guidance. I’m trying to obtain the pixel coordinates of the dot pattern image data that is stored in the attached file; I’m using this image to spatially calibrate my camera image. Is there a way to automate the detection of these dots? Thanks in advance for any guidance. image analysis, feature detection, spatial calibration MATLAB Answers — New Questions
Read datastore with variables of mixed classes
I have a large datastore as a csv file. A couple of variables have occasional alphabetical letters (e.g., "C") mixed in with observations that are otherwise numerals. dsread reports errors as seen below. What steps allow me to read the datastore, correcting for occasional errors?
Are there methods to construct/define the datastore such that a read recognizes the letters?
Error using matlab.io.datastore.TabularTextDatastore/readData (line 78)
Unable to parse a "Numeric" field when reading row 81, field 16.
Actual Text: "C,27108,16,16,C"
Expected: A number or literal "NaN", "Inf". (possibly signed, case insensitive)
Error in matlab.io.datastore.TabularDatastore/read (line 174)
[t, info] = ds.readData();
Error in untitled (line 11)
dC = read(ds);
Caused by:
Reading the variable name ‘RET’ using format ‘%f’ from file:
‘C:UsersdbrownBoxBrown_CarldatarawDistributionsDaily_Returns_CRSP_S&P500_1962-2024.csv’
starting at offset 1787951.I have a large datastore as a csv file. A couple of variables have occasional alphabetical letters (e.g., "C") mixed in with observations that are otherwise numerals. dsread reports errors as seen below. What steps allow me to read the datastore, correcting for occasional errors?
Are there methods to construct/define the datastore such that a read recognizes the letters?
Error using matlab.io.datastore.TabularTextDatastore/readData (line 78)
Unable to parse a "Numeric" field when reading row 81, field 16.
Actual Text: "C,27108,16,16,C"
Expected: A number or literal "NaN", "Inf". (possibly signed, case insensitive)
Error in matlab.io.datastore.TabularDatastore/read (line 174)
[t, info] = ds.readData();
Error in untitled (line 11)
dC = read(ds);
Caused by:
Reading the variable name ‘RET’ using format ‘%f’ from file:
‘C:UsersdbrownBoxBrown_CarldatarawDistributionsDaily_Returns_CRSP_S&P500_1962-2024.csv’
starting at offset 1787951. I have a large datastore as a csv file. A couple of variables have occasional alphabetical letters (e.g., "C") mixed in with observations that are otherwise numerals. dsread reports errors as seen below. What steps allow me to read the datastore, correcting for occasional errors?
Are there methods to construct/define the datastore such that a read recognizes the letters?
Error using matlab.io.datastore.TabularTextDatastore/readData (line 78)
Unable to parse a "Numeric" field when reading row 81, field 16.
Actual Text: "C,27108,16,16,C"
Expected: A number or literal "NaN", "Inf". (possibly signed, case insensitive)
Error in matlab.io.datastore.TabularDatastore/read (line 174)
[t, info] = ds.readData();
Error in untitled (line 11)
dC = read(ds);
Caused by:
Reading the variable name ‘RET’ using format ‘%f’ from file:
‘C:UsersdbrownBoxBrown_CarldatarawDistributionsDaily_Returns_CRSP_S&P500_1962-2024.csv’
starting at offset 1787951. datastore, mixed class variables MATLAB Answers — New Questions
To apply Naive Bayes as weight calculater with ELM
Now, I want to implement Naive Bayes algorithm to calculate the weight metrices of ELM. Can some one help me to perform this and give me a code fro this in matlabNow, I want to implement Naive Bayes algorithm to calculate the weight metrices of ELM. Can some one help me to perform this and give me a code fro this in matlab Now, I want to implement Naive Bayes algorithm to calculate the weight metrices of ELM. Can some one help me to perform this and give me a code fro this in matlab naive bayes, elm MATLAB Answers — New Questions
how to evaluate the integral of the expression involving bessel functions.
I have the following expression which i need to find.
then how i can find the integration? here this k is vector which contain k0,k1,k2, and same d and e is also a vector which contain d1,d2,d3 and e1, e2 ,e3 . and is also given. Then how i can evaluate this integration.I have the following expression which i need to find.
then how i can find the integration? here this k is vector which contain k0,k1,k2, and same d and e is also a vector which contain d1,d2,d3 and e1, e2 ,e3 . and is also given. Then how i can evaluate this integration. I have the following expression which i need to find.
then how i can find the integration? here this k is vector which contain k0,k1,k2, and same d and e is also a vector which contain d1,d2,d3 and e1, e2 ,e3 . and is also given. Then how i can evaluate this integration. numerical integration MATLAB Answers — New Questions
Teams Gains New Accent Colors
Keep the Default Accent Color or Choose New One
I thought that life was complete when Teams delivered multiple emoji reactions for messages. Now I know I was mistaken because MC1115312 (14 July 2025, Microsoft 365 roadmap item Microsoft 365 roadmap item 497139) announces the arrival of customizable accent colors, which begin to roll out for Teams desktop and browser (but not mobile) clients in late July 2025. Worldwide deployment is scheduled to be complete by the end of August 2025.
I’m unsure of quite how many people have ever woken up saying how nice it would be if Teams supported a selectable accent color – or how many people understand the purpose of an accent color. Mozilla documentation explains that an accent color is a cascading style sheet (CSS) property that sets the color of certain user interface controls.
Selecting a Theme Accent Color
Given that the Teams UX is basically a big browser app, it doesn’t come as a surprise that a style sheet property is involved, but what does it do? Well, users can select a color from a set presented in the Appearance section of the Settings app (Figure 1). According to Microsoft, this is a “visual customization” of the Teams interface that “enhances the user experience.”
The ten colors in the set range from the default (a wishy-washy light blue) to Red to Teal to Pink to Grey. You can’t add extra colors, so Teams can’t comply with expensive corporate brandings that feature an exact shade defined in a Pantone code. There is no administrative control available to set an accent color for users or to disable the option to select an accent color. Choosing an accent color is a purely cosmetic change that is user-driven to reflect personal rather than corporate choice.
You might scoff about the need to respect corporate branding, but I remember a heated debate inside Digital Equipment Corporation when a new CEO decided to refresh the iconic logo with new colors. Cue a surprisingly vicious fight between people who liked different shades of burgundy…
How Teams Uses an Accent Color
When you select a new accent color, Teams uses that color for many different elements in its user interface. The best example I could come up with is from the new threaded layout for channels where the accent color is used to highlight the base topic for a thread. I chose Red as my account color, and you can see the effect in Figure 2. Other elements that use the color include the count of notifications at the top of the screen, hyperlinks, and the display names of conversation participants.
After selecting such a bold color, you can appreciate why the Teams developers chose a muted color as the default (the first color in the list of available accent colors). Figure 3 shows an even more garish appearance using a yellow accent. Of course, beauty is in the eye of the beholder, and you might consider this to be just the kind of thing you want to see when browsing conversations.
Teams uses the chosen accent color in both home and host tenants, so if you’re a guest member of teams in other tenants, your selected color shows up there too. However, the color choice is specific to a workstation, and if you use Teams on another device, you’ll get whatever color is selected there.
One oddity I noticed is that selecting a color in Teams affects the display of other applications. For example, this blog is hosted by WordPress, and the Jetpack stats view (of page views, etc.) changed its color when I selected a new color in Teams. This might just be coincidence, but that’s less likely when the same thing happens on two PCs.
Customization is Good
I don’t think anyone can argue that the provision of options to allow users to customize their working environment is a bad thing. However, sometimes I wonder why effort is expended on developments like selectable accent colors when so much else could be done to address other issues.
So much change, all the time. It’s a challenge to stay abreast of all the updates Microsoft makes across the Microsoft 365 ecosystem. Subscribe to the Office 365 for IT Pros eBook to receive monthly insights into what happens, why it happens, and what new features and capabilities mean for your tenant.
How can I change the font size of MsgBox?
if f==0 || f <0
Message = sprintf(‘Serbestlik derecesi %dn DENGELEME YOK!!! ‘,f);
h = msgbox(Message,…
‘Dikkat’, ‘warn’);
endif f==0 || f <0
Message = sprintf(‘Serbestlik derecesi %dn DENGELEME YOK!!! ‘,f);
h = msgbox(Message,…
‘Dikkat’, ‘warn’);
end if f==0 || f <0
Message = sprintf(‘Serbestlik derecesi %dn DENGELEME YOK!!! ‘,f);
h = msgbox(Message,…
‘Dikkat’, ‘warn’);
end msgbox, fontsize, font, size MATLAB Answers — New Questions
sinus wave with chosen number of variating period
Hi,
I am trying to simulate a refractive index change in a medium, to do that I need to accurately model the evolution of said index with a sinusoidal function with variating period (see picture below for an exemple).
The function is written as n(z)=n0+n1*cos(phi(z)) (n being the index), with phi(z)=alpha/(z+beta), I would expect that fixing beta and calculating alpha for alpha=nT*2*pi*(zmax+beta) (with nT the number of period in the interval from z=0 to z=zmax) would give me a function with nT period but it does not, where did I go wrong?
ThanksHi,
I am trying to simulate a refractive index change in a medium, to do that I need to accurately model the evolution of said index with a sinusoidal function with variating period (see picture below for an exemple).
The function is written as n(z)=n0+n1*cos(phi(z)) (n being the index), with phi(z)=alpha/(z+beta), I would expect that fixing beta and calculating alpha for alpha=nT*2*pi*(zmax+beta) (with nT the number of period in the interval from z=0 to z=zmax) would give me a function with nT period but it does not, where did I go wrong?
Thanks Hi,
I am trying to simulate a refractive index change in a medium, to do that I need to accurately model the evolution of said index with a sinusoidal function with variating period (see picture below for an exemple).
The function is written as n(z)=n0+n1*cos(phi(z)) (n being the index), with phi(z)=alpha/(z+beta), I would expect that fixing beta and calculating alpha for alpha=nT*2*pi*(zmax+beta) (with nT the number of period in the interval from z=0 to z=zmax) would give me a function with nT period but it does not, where did I go wrong?
Thanks matlab, mathematics MATLAB Answers — New Questions
The export of MATLAB graphics may not be suitable for high-resolution screens
When I export an existing fig graph, its size does not match the content within the display interface.
Initially I found there is an error in HiDPI adaption.
My coumputer’s screen is in 200% scale. When I export the figure, the size seems to be double itself. As I halving the lenght or the width, it become normal.When I export an existing fig graph, its size does not match the content within the display interface.
Initially I found there is an error in HiDPI adaption.
My coumputer’s screen is in 200% scale. When I export the figure, the size seems to be double itself. As I halving the lenght or the width, it become normal. When I export an existing fig graph, its size does not match the content within the display interface.
Initially I found there is an error in HiDPI adaption.
My coumputer’s screen is in 200% scale. When I export the figure, the size seems to be double itself. As I halving the lenght or the width, it become normal. figure, export MATLAB Answers — New Questions
Issue with contourfm from Matlab 2024b
Hello,
I have to plot some data over these coordinates:
Until Matlab 2024a release I was able to correctly do it with contourfm through the code line:
contourfm(latPlot,lonPlot,data,CXanom(lp,1):0.125:CXanom(lp,2),’LineStyle’,’none’);
From Matlab 2024b release, lat and lon are not accepted anymore and there is the need to create reference raster cells. Here the code for Matlab 2024b:
ax=worldmap([min(latPlot(:)),max(latPlot(:))],[min(lonPlot(:)),max(lonPlot(:))]);
RefCells=georefcells([min(latPlot(:)),max(latPlot(:))],[min(lonPlot(:)),max(lonPlot(:))],[size(latPlot)]);
contourfm(data,RefCells,CXanom(lp,1):0.125:CXanom(lp,2),’LineStyle’,’none’);
hold on;
[C,h]=contourm(data,RefCells,CXanom(lp,1):StepLineAnom:CXanom(lp,2),’k’);
if isempty(C)
continue;
else
clm=clabelm(C,h,CXanom(lp,1):StepLineAnom:CXanom(lp,2));
for kk=1:numel(clm)
clm(kk).BackgroundColor=’none’;
clm(kk).FontWeight=’bold’;
clm(kk).Color=’k’;
end
for kk=1:numel(h.Children)
h.Children(kk).LineStyle=’:’;
end
end
plotm(BordersWorldHR(:,2),BordersWorldHR(:,1),’k’);
p=plotm(LatCC,LonCC,’xw’);
p.MarkerSize=8;
p.LineWidth=2;
p.MarkerEdgeColor=[0.96,0.96,0.96];
p.MarkerFaceColor=[0.96,0.96,0.96];
setm(ax,’FontSize’,10);
colormap(turbo);
hc=colorbar;
ylabel(hc,[‘TB Anomaly ‘,AMSUA_ch{ch},’ GHz (K)’]);
hc.FontSize=9;
hc.Ticks=CXanom(lp,1):(CXanom(lp,2)-CXanom(lp,1))/size(CMP1.(FN1),1):CXanom(lp,2);
hc.TickLabels=num2str(hc.Ticks’,’%.1f’);
clim(CXanom(lp,:));
hl=legend(p,’Min MSLP’);
hl.Location=’NorthWest’;
hl.FontSize=8;
hl.Color=[0.82,0.82,0.82];
set(gcf,’InvertHardCopy’,’off’);
What I get is the following:
but what I have to get is the following (made with pcolorm):
Can anyone help me to fix this issue? I attach both the data and the figures. Thanks.Hello,
I have to plot some data over these coordinates:
Until Matlab 2024a release I was able to correctly do it with contourfm through the code line:
contourfm(latPlot,lonPlot,data,CXanom(lp,1):0.125:CXanom(lp,2),’LineStyle’,’none’);
From Matlab 2024b release, lat and lon are not accepted anymore and there is the need to create reference raster cells. Here the code for Matlab 2024b:
ax=worldmap([min(latPlot(:)),max(latPlot(:))],[min(lonPlot(:)),max(lonPlot(:))]);
RefCells=georefcells([min(latPlot(:)),max(latPlot(:))],[min(lonPlot(:)),max(lonPlot(:))],[size(latPlot)]);
contourfm(data,RefCells,CXanom(lp,1):0.125:CXanom(lp,2),’LineStyle’,’none’);
hold on;
[C,h]=contourm(data,RefCells,CXanom(lp,1):StepLineAnom:CXanom(lp,2),’k’);
if isempty(C)
continue;
else
clm=clabelm(C,h,CXanom(lp,1):StepLineAnom:CXanom(lp,2));
for kk=1:numel(clm)
clm(kk).BackgroundColor=’none’;
clm(kk).FontWeight=’bold’;
clm(kk).Color=’k’;
end
for kk=1:numel(h.Children)
h.Children(kk).LineStyle=’:’;
end
end
plotm(BordersWorldHR(:,2),BordersWorldHR(:,1),’k’);
p=plotm(LatCC,LonCC,’xw’);
p.MarkerSize=8;
p.LineWidth=2;
p.MarkerEdgeColor=[0.96,0.96,0.96];
p.MarkerFaceColor=[0.96,0.96,0.96];
setm(ax,’FontSize’,10);
colormap(turbo);
hc=colorbar;
ylabel(hc,[‘TB Anomaly ‘,AMSUA_ch{ch},’ GHz (K)’]);
hc.FontSize=9;
hc.Ticks=CXanom(lp,1):(CXanom(lp,2)-CXanom(lp,1))/size(CMP1.(FN1),1):CXanom(lp,2);
hc.TickLabels=num2str(hc.Ticks’,’%.1f’);
clim(CXanom(lp,:));
hl=legend(p,’Min MSLP’);
hl.Location=’NorthWest’;
hl.FontSize=8;
hl.Color=[0.82,0.82,0.82];
set(gcf,’InvertHardCopy’,’off’);
What I get is the following:
but what I have to get is the following (made with pcolorm):
Can anyone help me to fix this issue? I attach both the data and the figures. Thanks. Hello,
I have to plot some data over these coordinates:
Until Matlab 2024a release I was able to correctly do it with contourfm through the code line:
contourfm(latPlot,lonPlot,data,CXanom(lp,1):0.125:CXanom(lp,2),’LineStyle’,’none’);
From Matlab 2024b release, lat and lon are not accepted anymore and there is the need to create reference raster cells. Here the code for Matlab 2024b:
ax=worldmap([min(latPlot(:)),max(latPlot(:))],[min(lonPlot(:)),max(lonPlot(:))]);
RefCells=georefcells([min(latPlot(:)),max(latPlot(:))],[min(lonPlot(:)),max(lonPlot(:))],[size(latPlot)]);
contourfm(data,RefCells,CXanom(lp,1):0.125:CXanom(lp,2),’LineStyle’,’none’);
hold on;
[C,h]=contourm(data,RefCells,CXanom(lp,1):StepLineAnom:CXanom(lp,2),’k’);
if isempty(C)
continue;
else
clm=clabelm(C,h,CXanom(lp,1):StepLineAnom:CXanom(lp,2));
for kk=1:numel(clm)
clm(kk).BackgroundColor=’none’;
clm(kk).FontWeight=’bold’;
clm(kk).Color=’k’;
end
for kk=1:numel(h.Children)
h.Children(kk).LineStyle=’:’;
end
end
plotm(BordersWorldHR(:,2),BordersWorldHR(:,1),’k’);
p=plotm(LatCC,LonCC,’xw’);
p.MarkerSize=8;
p.LineWidth=2;
p.MarkerEdgeColor=[0.96,0.96,0.96];
p.MarkerFaceColor=[0.96,0.96,0.96];
setm(ax,’FontSize’,10);
colormap(turbo);
hc=colorbar;
ylabel(hc,[‘TB Anomaly ‘,AMSUA_ch{ch},’ GHz (K)’]);
hc.FontSize=9;
hc.Ticks=CXanom(lp,1):(CXanom(lp,2)-CXanom(lp,1))/size(CMP1.(FN1),1):CXanom(lp,2);
hc.TickLabels=num2str(hc.Ticks’,’%.1f’);
clim(CXanom(lp,:));
hl=legend(p,’Min MSLP’);
hl.Location=’NorthWest’;
hl.FontSize=8;
hl.Color=[0.82,0.82,0.82];
set(gcf,’InvertHardCopy’,’off’);
What I get is the following:
but what I have to get is the following (made with pcolorm):
Can anyone help me to fix this issue? I attach both the data and the figures. Thanks. contourfm MATLAB Answers — New Questions
N310 Target Platform not appearing in HDL Coder
I have been trying to follow the NI Targeting Workflow for IP Core generation for an USRP N310 SDR. I have installed Vivado and appended it to the system path, and have been successful in connecting with the SDR using the radioSetupWizard. In Simulink, using the SDRu Reciever block, I am successfully able to read data from the Rx channels of the radio, so there is no issue with the connectivity here.
However, when I try to use the HDL coder, it seems that the radio is not recognised. I can load the default fpga using sdruload, so I assume it’s not that I can’t access the fpga, but I cannot see it, nor any other NI radio (other than the E310 which appeared after running setupusrpe3xxrepositories;) as a target platform for the HDL coder.
I would expect to see this listed as USRP N310 as in the example, but it does not appear. I have tried uninstalling and reinstalling everything, so I am at a loss of how to proceed. Any help would be greatly appreciated.I have been trying to follow the NI Targeting Workflow for IP Core generation for an USRP N310 SDR. I have installed Vivado and appended it to the system path, and have been successful in connecting with the SDR using the radioSetupWizard. In Simulink, using the SDRu Reciever block, I am successfully able to read data from the Rx channels of the radio, so there is no issue with the connectivity here.
However, when I try to use the HDL coder, it seems that the radio is not recognised. I can load the default fpga using sdruload, so I assume it’s not that I can’t access the fpga, but I cannot see it, nor any other NI radio (other than the E310 which appeared after running setupusrpe3xxrepositories;) as a target platform for the HDL coder.
I would expect to see this listed as USRP N310 as in the example, but it does not appear. I have tried uninstalling and reinstalling everything, so I am at a loss of how to proceed. Any help would be greatly appreciated. I have been trying to follow the NI Targeting Workflow for IP Core generation for an USRP N310 SDR. I have installed Vivado and appended it to the system path, and have been successful in connecting with the SDR using the radioSetupWizard. In Simulink, using the SDRu Reciever block, I am successfully able to read data from the Rx channels of the radio, so there is no issue with the connectivity here.
However, when I try to use the HDL coder, it seems that the radio is not recognised. I can load the default fpga using sdruload, so I assume it’s not that I can’t access the fpga, but I cannot see it, nor any other NI radio (other than the E310 which appeared after running setupusrpe3xxrepositories;) as a target platform for the HDL coder.
I would expect to see this listed as USRP N310 as in the example, but it does not appear. I have tried uninstalling and reinstalling everything, so I am at a loss of how to proceed. Any help would be greatly appreciated. code generation, usrp, ip-core generation MATLAB Answers — New Questions
Microsoft Introduces Exchange 2016/2019 Extended Security Program
Six Months of an Extended Security Update Program from October 2025 to April 2026
Those who aren’t dedicated followers of the EHLO blog might have missed two interesting posts this week. The first covers delicensing resiliency for Exchange Online and the news that Microsoft is reducing the threshold for this feature to 5,000 tenant mailboxes. I think the feature should be available to all Exchange Online tenants, but let’s leave that debate aside.
Coping with the consequences of a mailbox becoming delicensed isn’t such an issue for Exchange on-premises organizations. They have their own challenge, notably the need to upgrade to Exchange Server Subscription Edition (SE) before Exchange 2016 and Exchange 2019 exit support on October 14, 2025.
Updating a Server to Exchange Server SE is Boringly Easy
The second EHLO post of the week offers a lifeline to organizations who don’t believe that they can deploy Exchange Server SE by the October 2025 deadline. Performing an in-place server upgrade to Exchange Server SE is the easiest Exchange upgrade an on-premises administrator is likely to ever know. It’s been described as “boring” because literally nothing happens apart from version numbers being updated and a few other minor tweaks. The fact that Exchange 2019 and SE share the same documentation for system requirements testifies to the closeness of the two products.
Microsoft designed the upgrade to the first iteration of Exchange Server SE to be boring to remove the barrier where administrators believe that an Exchange upgrade is a major event with many potential problems lurking under the surface waiting to make a server inoperative. Read the documentation, follow the steps laid down, and your update will proceed smoothly.
Factors Stopping Upgrades Happening
Although the server upgrade is easy, there’s usually some other factors that come into play that can slow deployment. Now is peak vacation period so people might not be available. The organization might decide to introduce new hardware or roll out Windows Server 2025. This might be especially so when the organization runs Exchange 2016 on an older version of Windows Server (here’s the operating systems matrix). In any case, lots of preliminary steps might need to be resolved before anyone sits down to update a server.
To help organizations that are struggling to get their ducks in a row to allow the deployment of Exchange Server SE to proceed, Microsoft is therefore introducing a six-month Extended Security Update program. The idea is simple: After August 1, 2025, customers can contact their Microsoft account team to request a subscription to a new product SKU that entitles them to receive security updates for Exchange 2016 and Exchange 2019 for six months. The price of the SKU is per-server, and it’s assumed that the Microsoft account team knows how many servers a customer operates so that they can calculate an initial price before any discounts are negotiated. If you don’t have a Microsoft account team, call the local Microsoft office and get them involved.
There are several important points to consider before proceeding to enrol in the Extended Security Program:
- The agreement only lasts six months and Microsoft doesn’t plan to extend it past April 14, 2026.
- During the agreement, Microsoft will deliver security updates for problems that the Microsoft Security Response Center deems to be critical or important. In other words, a security issue must meet a threshold before Microsoft will create a security update for Exchange 2016/2019.
- Security updates issued through the program will be released privately to program participants. You won’t be able to download the updates from the Microsoft download center.
- There’s no guarantee that any security problems will emerge between October 15, 2025, and April 14, 2026. In other words, this is insurance in case a problem happens, and no refunds are coming if the security landscape remains calm throughout the six-month program lifetime.
- Microsoft says that they will inform program participants if a security update is available on Patch Tuesdays during the covered period.
- The Extended Security Update Program does not affect the end-of-lifetime support dates for Exchange 2016 and Exchange 2019. Those dates remain as they are. This program only covers security issues.
Not a Revenue Generating Opportunity
Cynics will say that this is yet another example of Microsoft adjusting deadlines, this time to create an opportunity for a little extra revenue by charging customers for six months of security insurance. Pragmatists will recognize just how slow Exchange Server updates have been since Exchange 2000 appeared. Given the engineering costs involved, I doubt Microsoft will make much if anything from the Extended Security Update program. This is no more and no less than a lifeline for those who need that extra time.
Your support pays for the time we need to track, analyze, and document the changing world of Microsoft 365 and Office 365. Only humans contribute to our work, which includes topics like Exchange Server SE that are important to hybrid Microsoft 365 deployments.
Output doesn’t display a value, just an empty space.
So, I’ve got 2 pulses (imp and S0) and their sum (Si). I’ve got to find minimum of sum (Si). And I approximate the sum with a polynome. I took derivatives (1-st and 2-nd order) of the sum and polynome.
I analyze derivatives, and decided to look for minimum of sum (Si), polynome and 2-nd derivatives.
But, in some cases the result is just empty, but size of variable is 1×999 double.
lb = -5;
ub = 15;
x_imp = linspace(lb, ub, 1001);
x = linspace(lb, ub, 1001);
imp = sech(x_imp);
S0 = sech(x-10);
imp1 = sech(x – 1);
S1 = 0.5 * (imp1 + S0);
xmin = -1;
xmax = 10;
% find inflection point Si
range_x = x(x>=xmin & x<=xmax);
range_S1 = S1(x>=xmin & x<=xmax);
MinPtsS1 = islocalmin(range_S1);
fprintf (‘x_S1 = %f , y_S1 = %f .n’, range_x(MinPtsS1), range_S1(MinPtsS1));
% polynom approximation pv
[p_S1, ~, mu] = polyfit(x, S1, 26);
pv_S1 = polyval (p_S1, x, [], mu);
% find inflection point of polynom pv
range_x = x(x>=xmin & x<=xmax);
range_pvS1 = pv_S1(x>=xmin & x<=xmax);
MinPts_pvS1 = islocalmin(range_pvS1);
fprintf(‘x_pvS1 = %f , y_pvS1 = %f .n’, range_x(MinPts_pvS1), range_pvS1(MinPts_pvS1));
% DIFF find inflection of diff2 Si, corresponding to inflection point of Si
dS1 = 20*diff (S1);
d2S1 = 10*diff(dS1);
range_x = x(x>=xmin & x<=xmin);
range_d2S1 = d2S1(x>=xmin & x<=xmin);
MinPts_d2S1 = islocalmin(range_d2S1);
fprintf(‘x_d2S1 = %f , y_d2S1 = %f .n’, range_x(MinPts_d2S1), range_d2S1(MinPts_d2S1));
% DIFF find inflection of diff2 polynom Si, corresponding to inflection point of Si
dpS1 = 20*diff(pv_S1);
dp2S1 = 20*diff(dpS1);
range_x = x(x>=xmin & x<=xmax);
range_dp2S1 = dp2S1(x>=xmin & x<=xmax);
MinPts_dp2S1 = islocalmin(range_dp2S1);
fprintf(‘x_dp2S1 = %f , y_dp2S1 = %f .n’, range_x(MinPts_dp2S1), range_dp2S1(MinPts_dp2S1));So, I’ve got 2 pulses (imp and S0) and their sum (Si). I’ve got to find minimum of sum (Si). And I approximate the sum with a polynome. I took derivatives (1-st and 2-nd order) of the sum and polynome.
I analyze derivatives, and decided to look for minimum of sum (Si), polynome and 2-nd derivatives.
But, in some cases the result is just empty, but size of variable is 1×999 double.
lb = -5;
ub = 15;
x_imp = linspace(lb, ub, 1001);
x = linspace(lb, ub, 1001);
imp = sech(x_imp);
S0 = sech(x-10);
imp1 = sech(x – 1);
S1 = 0.5 * (imp1 + S0);
xmin = -1;
xmax = 10;
% find inflection point Si
range_x = x(x>=xmin & x<=xmax);
range_S1 = S1(x>=xmin & x<=xmax);
MinPtsS1 = islocalmin(range_S1);
fprintf (‘x_S1 = %f , y_S1 = %f .n’, range_x(MinPtsS1), range_S1(MinPtsS1));
% polynom approximation pv
[p_S1, ~, mu] = polyfit(x, S1, 26);
pv_S1 = polyval (p_S1, x, [], mu);
% find inflection point of polynom pv
range_x = x(x>=xmin & x<=xmax);
range_pvS1 = pv_S1(x>=xmin & x<=xmax);
MinPts_pvS1 = islocalmin(range_pvS1);
fprintf(‘x_pvS1 = %f , y_pvS1 = %f .n’, range_x(MinPts_pvS1), range_pvS1(MinPts_pvS1));
% DIFF find inflection of diff2 Si, corresponding to inflection point of Si
dS1 = 20*diff (S1);
d2S1 = 10*diff(dS1);
range_x = x(x>=xmin & x<=xmin);
range_d2S1 = d2S1(x>=xmin & x<=xmin);
MinPts_d2S1 = islocalmin(range_d2S1);
fprintf(‘x_d2S1 = %f , y_d2S1 = %f .n’, range_x(MinPts_d2S1), range_d2S1(MinPts_d2S1));
% DIFF find inflection of diff2 polynom Si, corresponding to inflection point of Si
dpS1 = 20*diff(pv_S1);
dp2S1 = 20*diff(dpS1);
range_x = x(x>=xmin & x<=xmax);
range_dp2S1 = dp2S1(x>=xmin & x<=xmax);
MinPts_dp2S1 = islocalmin(range_dp2S1);
fprintf(‘x_dp2S1 = %f , y_dp2S1 = %f .n’, range_x(MinPts_dp2S1), range_dp2S1(MinPts_dp2S1)); So, I’ve got 2 pulses (imp and S0) and their sum (Si). I’ve got to find minimum of sum (Si). And I approximate the sum with a polynome. I took derivatives (1-st and 2-nd order) of the sum and polynome.
I analyze derivatives, and decided to look for minimum of sum (Si), polynome and 2-nd derivatives.
But, in some cases the result is just empty, but size of variable is 1×999 double.
lb = -5;
ub = 15;
x_imp = linspace(lb, ub, 1001);
x = linspace(lb, ub, 1001);
imp = sech(x_imp);
S0 = sech(x-10);
imp1 = sech(x – 1);
S1 = 0.5 * (imp1 + S0);
xmin = -1;
xmax = 10;
% find inflection point Si
range_x = x(x>=xmin & x<=xmax);
range_S1 = S1(x>=xmin & x<=xmax);
MinPtsS1 = islocalmin(range_S1);
fprintf (‘x_S1 = %f , y_S1 = %f .n’, range_x(MinPtsS1), range_S1(MinPtsS1));
% polynom approximation pv
[p_S1, ~, mu] = polyfit(x, S1, 26);
pv_S1 = polyval (p_S1, x, [], mu);
% find inflection point of polynom pv
range_x = x(x>=xmin & x<=xmax);
range_pvS1 = pv_S1(x>=xmin & x<=xmax);
MinPts_pvS1 = islocalmin(range_pvS1);
fprintf(‘x_pvS1 = %f , y_pvS1 = %f .n’, range_x(MinPts_pvS1), range_pvS1(MinPts_pvS1));
% DIFF find inflection of diff2 Si, corresponding to inflection point of Si
dS1 = 20*diff (S1);
d2S1 = 10*diff(dS1);
range_x = x(x>=xmin & x<=xmin);
range_d2S1 = d2S1(x>=xmin & x<=xmin);
MinPts_d2S1 = islocalmin(range_d2S1);
fprintf(‘x_d2S1 = %f , y_d2S1 = %f .n’, range_x(MinPts_d2S1), range_d2S1(MinPts_d2S1));
% DIFF find inflection of diff2 polynom Si, corresponding to inflection point of Si
dpS1 = 20*diff(pv_S1);
dp2S1 = 20*diff(dpS1);
range_x = x(x>=xmin & x<=xmax);
range_dp2S1 = dp2S1(x>=xmin & x<=xmax);
MinPts_dp2S1 = islocalmin(range_dp2S1);
fprintf(‘x_dp2S1 = %f , y_dp2S1 = %f .n’, range_x(MinPts_dp2S1), range_dp2S1(MinPts_dp2S1)); empty output, derivative, diff, polyval MATLAB Answers — New Questions
How to output STL format flie
I have a point matrix p whose size is 3×98065;the triangulation matrix t whose size is 3×196124 ;
How to output the data as a STL model.Thank you.I have a point matrix p whose size is 3×98065;the triangulation matrix t whose size is 3×196124 ;
How to output the data as a STL model.Thank you. I have a point matrix p whose size is 3×98065;the triangulation matrix t whose size is 3×196124 ;
How to output the data as a STL model.Thank you. output stl format flie, triangulation matrix, point matrix, export stl, write stl MATLAB Answers — New Questions
