Tag Archives: matlab
How to classify a folder of images?
I have a file contains a set of images including images of three denominations of currency. I need a MATLAB code to determine the number of images for each denomination of currency according to its features and colors.I have a file contains a set of images including images of three denominations of currency. I need a MATLAB code to determine the number of images for each denomination of currency according to its features and colors. I have a file contains a set of images including images of three denominations of currency. I need a MATLAB code to determine the number of images for each denomination of currency according to its features and colors. classify a folder of images MATLAB Answers — New Questions
how to modify code for distributed delay
I have a code, which gives a solution of a delay logistic equation with discrete delay.
tau = 1;
tspan = [0 20];
y0 = 0.5;
sol = dde23(@ddefunc, tau, y0, tspan);
% Plot the solution
figure;
plot(sol.x, sol.y, ‘LineWidth’, 2);
xlabel(‘Time (days)’);
ylabel(‘Population’);
legend(‘y’);
% Define the delay differential equation
function g = ddefunc(t, y, Z)
r = 1.5;
y_tau = Z;
g = r * y * (1 – y_tau);
end
Now I want to modify my code for distributed delay as attached below.
Can someone guide me how to deal with distributed delayI have a code, which gives a solution of a delay logistic equation with discrete delay.
tau = 1;
tspan = [0 20];
y0 = 0.5;
sol = dde23(@ddefunc, tau, y0, tspan);
% Plot the solution
figure;
plot(sol.x, sol.y, ‘LineWidth’, 2);
xlabel(‘Time (days)’);
ylabel(‘Population’);
legend(‘y’);
% Define the delay differential equation
function g = ddefunc(t, y, Z)
r = 1.5;
y_tau = Z;
g = r * y * (1 – y_tau);
end
Now I want to modify my code for distributed delay as attached below.
Can someone guide me how to deal with distributed delay I have a code, which gives a solution of a delay logistic equation with discrete delay.
tau = 1;
tspan = [0 20];
y0 = 0.5;
sol = dde23(@ddefunc, tau, y0, tspan);
% Plot the solution
figure;
plot(sol.x, sol.y, ‘LineWidth’, 2);
xlabel(‘Time (days)’);
ylabel(‘Population’);
legend(‘y’);
% Define the delay differential equation
function g = ddefunc(t, y, Z)
r = 1.5;
y_tau = Z;
g = r * y * (1 – y_tau);
end
Now I want to modify my code for distributed delay as attached below.
Can someone guide me how to deal with distributed delay distributed delay, delay differentia equations, solve MATLAB Answers — New Questions
Sizeof double float int etc
Hello there,
I need to know how to find an equivallent function in Matlab to the sizeof function in c++.
For example, in c++ if I write sizeof(double) I would get the amount of memory needed to store a double.
I need something very similar with a matrix now. I will be storing bigger and bigger matrix and I need to find their size in the memory.
Could someone of you please help me?
all best,
:)Hello there,
I need to know how to find an equivallent function in Matlab to the sizeof function in c++.
For example, in c++ if I write sizeof(double) I would get the amount of memory needed to store a double.
I need something very similar with a matrix now. I will be storing bigger and bigger matrix and I need to find their size in the memory.
Could someone of you please help me?
all best,
🙂 Hello there,
I need to know how to find an equivallent function in Matlab to the sizeof function in c++.
For example, in c++ if I write sizeof(double) I would get the amount of memory needed to store a double.
I need something very similar with a matrix now. I will be storing bigger and bigger matrix and I need to find their size in the memory.
Could someone of you please help me?
all best,
🙂 sizeof, memory, size MATLAB Answers — New Questions
To RESHAPE number of elements must not change
Hi all, im trying to do simple ERP study using EEGLAB. To RESHAPE number of elements must not change, such an error messahe was thrown. let me know how to fix it. ThanksHi all, im trying to do simple ERP study using EEGLAB. To RESHAPE number of elements must not change, such an error messahe was thrown. let me know how to fix it. Thanks Hi all, im trying to do simple ERP study using EEGLAB. To RESHAPE number of elements must not change, such an error messahe was thrown. let me know how to fix it. Thanks please help MATLAB Answers — New Questions
How to datasample exponential data without losing the exponential decay?
Hi all!
So this is the question:
I have a Table with one column (std_spk_avg, attached). This column has 400 numbers. The data follow exponential distribution, so when i normally resample using ‘resample’ function in matlab to obtain 1000 iterations, i lose the exponential decay in each iteration…
How can i code with this function so as not to lose the exponential decay in my 1000 iterations?
Thanks you all in advance :)Hi all!
So this is the question:
I have a Table with one column (std_spk_avg, attached). This column has 400 numbers. The data follow exponential distribution, so when i normally resample using ‘resample’ function in matlab to obtain 1000 iterations, i lose the exponential decay in each iteration…
How can i code with this function so as not to lose the exponential decay in my 1000 iterations?
Thanks you all in advance 🙂 Hi all!
So this is the question:
I have a Table with one column (std_spk_avg, attached). This column has 400 numbers. The data follow exponential distribution, so when i normally resample using ‘resample’ function in matlab to obtain 1000 iterations, i lose the exponential decay in each iteration…
How can i code with this function so as not to lose the exponential decay in my 1000 iterations?
Thanks you all in advance 🙂 datasample, exponential, table, exponential data, struct MATLAB Answers — New Questions
how to organize input dimensions for LSTM classification
Hi guys,
I’m trying to train a lstm using sequential data to predict classes, and I’m a little confused by the format of input data and labels.
For the sake of simplicity, I’ll use an example to mimic my situation.
let’s say I’m trying to use temperature data to predict 3 cities: A, B, and C.
Within each city, i have temperature readings from 10 therometers over 2 seconds at a sample frequency of 100 hz.
So far, at each observation, I have a 200 by 10 matrix (time point by therometer).
temperature_matrix = randi(40, 200, 10) % pseudodata
We collected the temperature data 40 times throughout the day at each city, and this will give us 120 observations (3 cities * 40). Within each observation, I have a 200 by 10 matrix.
As for my input format, I now have a 120 by 1 cell array, and again within each cell array is a 200 by 10 matrix.
temperature_input = cell(120,1)
for ii = 1:length(temperature_input)
temperature_input{ii} = randi(40, 200, 10)
end
labels = [repmat("city A", 40,1); repmat("city B", 40,1); repmat("city C", 40,1)]
Per my undstanding, if I were to have a time step of 10, i should make a sliding window with a size of 5, and move it down the time dimenssion at a moving step of 1. That is to say, for each 200 by 10 temperature_matrix, I now slice it into 196 2D arrays, where each array is 5 by 10 (window size by therometer).
My question is how this sliding window plays a part in the input format? the sliding window create the fourth dimension in my example. The other three dimension is observation, time, and therometer. I think my overall structure is still a 120 by 1 cell array, but the dimenssions within each entry, I dont know how to organize them.
Also, out of curiosity, will it mess up the structure i transpose the time point by therometer matrice? I’m only asking between I’ve seen examples on the sequencce either in row or column.
Best,
FYHi guys,
I’m trying to train a lstm using sequential data to predict classes, and I’m a little confused by the format of input data and labels.
For the sake of simplicity, I’ll use an example to mimic my situation.
let’s say I’m trying to use temperature data to predict 3 cities: A, B, and C.
Within each city, i have temperature readings from 10 therometers over 2 seconds at a sample frequency of 100 hz.
So far, at each observation, I have a 200 by 10 matrix (time point by therometer).
temperature_matrix = randi(40, 200, 10) % pseudodata
We collected the temperature data 40 times throughout the day at each city, and this will give us 120 observations (3 cities * 40). Within each observation, I have a 200 by 10 matrix.
As for my input format, I now have a 120 by 1 cell array, and again within each cell array is a 200 by 10 matrix.
temperature_input = cell(120,1)
for ii = 1:length(temperature_input)
temperature_input{ii} = randi(40, 200, 10)
end
labels = [repmat("city A", 40,1); repmat("city B", 40,1); repmat("city C", 40,1)]
Per my undstanding, if I were to have a time step of 10, i should make a sliding window with a size of 5, and move it down the time dimenssion at a moving step of 1. That is to say, for each 200 by 10 temperature_matrix, I now slice it into 196 2D arrays, where each array is 5 by 10 (window size by therometer).
My question is how this sliding window plays a part in the input format? the sliding window create the fourth dimension in my example. The other three dimension is observation, time, and therometer. I think my overall structure is still a 120 by 1 cell array, but the dimenssions within each entry, I dont know how to organize them.
Also, out of curiosity, will it mess up the structure i transpose the time point by therometer matrice? I’m only asking between I’ve seen examples on the sequencce either in row or column.
Best,
FY Hi guys,
I’m trying to train a lstm using sequential data to predict classes, and I’m a little confused by the format of input data and labels.
For the sake of simplicity, I’ll use an example to mimic my situation.
let’s say I’m trying to use temperature data to predict 3 cities: A, B, and C.
Within each city, i have temperature readings from 10 therometers over 2 seconds at a sample frequency of 100 hz.
So far, at each observation, I have a 200 by 10 matrix (time point by therometer).
temperature_matrix = randi(40, 200, 10) % pseudodata
We collected the temperature data 40 times throughout the day at each city, and this will give us 120 observations (3 cities * 40). Within each observation, I have a 200 by 10 matrix.
As for my input format, I now have a 120 by 1 cell array, and again within each cell array is a 200 by 10 matrix.
temperature_input = cell(120,1)
for ii = 1:length(temperature_input)
temperature_input{ii} = randi(40, 200, 10)
end
labels = [repmat("city A", 40,1); repmat("city B", 40,1); repmat("city C", 40,1)]
Per my undstanding, if I were to have a time step of 10, i should make a sliding window with a size of 5, and move it down the time dimenssion at a moving step of 1. That is to say, for each 200 by 10 temperature_matrix, I now slice it into 196 2D arrays, where each array is 5 by 10 (window size by therometer).
My question is how this sliding window plays a part in the input format? the sliding window create the fourth dimension in my example. The other three dimension is observation, time, and therometer. I think my overall structure is still a 120 by 1 cell array, but the dimenssions within each entry, I dont know how to organize them.
Also, out of curiosity, will it mess up the structure i transpose the time point by therometer matrice? I’m only asking between I’ve seen examples on the sequencce either in row or column.
Best,
FY lstm, input, dimension MATLAB Answers — New Questions
How to create a component reference in the system composer from a simscape component
Hello,
I have a Simscape Isothermal Fluid component that is an isolated component (it have its own test harness, test cases and requirements. You can see it is composed with simscape signals and simulink signals.
I would like to build a system composer, were this component is part of. But when I add a "reference component" on the system composer ad link to the compoenent, the physical lines does not come.
The only way I made it works is creating the sismcape compoenent inside the system composer, but this way I need to manage changes and so on inside the composer.
Any solution to create a simscape component that can be referenced inside the system composer and have the physical connections available?Hello,
I have a Simscape Isothermal Fluid component that is an isolated component (it have its own test harness, test cases and requirements. You can see it is composed with simscape signals and simulink signals.
I would like to build a system composer, were this component is part of. But when I add a "reference component" on the system composer ad link to the compoenent, the physical lines does not come.
The only way I made it works is creating the sismcape compoenent inside the system composer, but this way I need to manage changes and so on inside the composer.
Any solution to create a simscape component that can be referenced inside the system composer and have the physical connections available? Hello,
I have a Simscape Isothermal Fluid component that is an isolated component (it have its own test harness, test cases and requirements. You can see it is composed with simscape signals and simulink signals.
I would like to build a system composer, were this component is part of. But when I add a "reference component" on the system composer ad link to the compoenent, the physical lines does not come.
The only way I made it works is creating the sismcape compoenent inside the system composer, but this way I need to manage changes and so on inside the composer.
Any solution to create a simscape component that can be referenced inside the system composer and have the physical connections available? simscape, system composer MATLAB Answers — New Questions
In Simulink, How to decode CAN data with length greater than 8?
There is an issue using CAN Unpack to decode CAN message with length greater than 8. Is there any other recommanded way to decode CAN data? For starter, I have used bit extract and bitwise AND Shift Arithmetic to extract bits in simulink. I’m not sure if matlab function in simulink can also handle this if it’s possible.There is an issue using CAN Unpack to decode CAN message with length greater than 8. Is there any other recommanded way to decode CAN data? For starter, I have used bit extract and bitwise AND Shift Arithmetic to extract bits in simulink. I’m not sure if matlab function in simulink can also handle this if it’s possible. There is an issue using CAN Unpack to decode CAN message with length greater than 8. Is there any other recommanded way to decode CAN data? For starter, I have used bit extract and bitwise AND Shift Arithmetic to extract bits in simulink. I’m not sure if matlab function in simulink can also handle this if it’s possible. data, control MATLAB Answers — New Questions
Why do I get an invalid Python executable path error when running the “pyenv” function?
Previously I was able to use the "pyenv" function in MATLAB with my Python environment. However, now when I try to use the "pyenv" function, I get the following error message. Why am I suddenly receiving this error?
Error using pyenv
‘<path>’ is not a path to a valid Python executable.Previously I was able to use the "pyenv" function in MATLAB with my Python environment. However, now when I try to use the "pyenv" function, I get the following error message. Why am I suddenly receiving this error?
Error using pyenv
‘<path>’ is not a path to a valid Python executable. Previously I was able to use the "pyenv" function in MATLAB with my Python environment. However, now when I try to use the "pyenv" function, I get the following error message. Why am I suddenly receiving this error?
Error using pyenv
‘<path>’ is not a path to a valid Python executable. python, pyenv MATLAB Answers — New Questions
Finding the closest coordinate from a surface plot based on a X, Y location
Hello, I want to extrapolate a point (longitude,latitude) from the coordinates of a surface file (attached here as "slab_strike") as it is empty (Strike=NaN) when using interp2 as the points are outside the boundary. Despsite I used the option "nearest" is empty anyway.
% Coordinates of the points:
lat_GMM= -17.8990;
lon_GMM=-73.5295;
% The surface plot
load slab_strike % Loading the slab strike
Slab_strike.x=x
Slab_strike.y=y
Slab_strike.z=z
Strike = interp2(Slab_strike.x,Slab_strike.y,Slab_strike.z,lon_GMM,lat_GMM)
As Strike=NaN, there is a way I can choose the closest point value from the surface instead.
I would appreciate the helpHello, I want to extrapolate a point (longitude,latitude) from the coordinates of a surface file (attached here as "slab_strike") as it is empty (Strike=NaN) when using interp2 as the points are outside the boundary. Despsite I used the option "nearest" is empty anyway.
% Coordinates of the points:
lat_GMM= -17.8990;
lon_GMM=-73.5295;
% The surface plot
load slab_strike % Loading the slab strike
Slab_strike.x=x
Slab_strike.y=y
Slab_strike.z=z
Strike = interp2(Slab_strike.x,Slab_strike.y,Slab_strike.z,lon_GMM,lat_GMM)
As Strike=NaN, there is a way I can choose the closest point value from the surface instead.
I would appreciate the help Hello, I want to extrapolate a point (longitude,latitude) from the coordinates of a surface file (attached here as "slab_strike") as it is empty (Strike=NaN) when using interp2 as the points are outside the boundary. Despsite I used the option "nearest" is empty anyway.
% Coordinates of the points:
lat_GMM= -17.8990;
lon_GMM=-73.5295;
% The surface plot
load slab_strike % Loading the slab strike
Slab_strike.x=x
Slab_strike.y=y
Slab_strike.z=z
Strike = interp2(Slab_strike.x,Slab_strike.y,Slab_strike.z,lon_GMM,lat_GMM)
As Strike=NaN, there is a way I can choose the closest point value from the surface instead.
I would appreciate the help selecting the closest point reference MATLAB Answers — New Questions
Issue connecting Simulink to Arduino Nano 33 IoT
I’m having an issue connecting my Arduino Nano 33 IoT to simulink. When I try to run it, I get the error message: "Unrecognized feild name " HostCOMPort" " I’m unsure how to resolve this and would greatly appricate the help!
The device shows up in my device manager and I can run code in Arduino IDE and Matlab without issues. Its only when I use Simulink is there a problem. Im using the cable that came in the Engineering Rev 2 kit from Arduino as well as a usb to usb-c converter to plug into my surface go to connect my computer to the Nano. I am able to run a regular Arduino Uno using the same setup through simiulink.
I’ve notcied that everytime I try to run the simulink program, the port in the device manager will change from "Arduino Nano 33 IoT" to the bootloader version. And also Matlab will tell me that an arduino device is detected again. My guess is that the Nano is restarting everytime or something? Im not really sure.I’m having an issue connecting my Arduino Nano 33 IoT to simulink. When I try to run it, I get the error message: "Unrecognized feild name " HostCOMPort" " I’m unsure how to resolve this and would greatly appricate the help!
The device shows up in my device manager and I can run code in Arduino IDE and Matlab without issues. Its only when I use Simulink is there a problem. Im using the cable that came in the Engineering Rev 2 kit from Arduino as well as a usb to usb-c converter to plug into my surface go to connect my computer to the Nano. I am able to run a regular Arduino Uno using the same setup through simiulink.
I’ve notcied that everytime I try to run the simulink program, the port in the device manager will change from "Arduino Nano 33 IoT" to the bootloader version. And also Matlab will tell me that an arduino device is detected again. My guess is that the Nano is restarting everytime or something? Im not really sure. I’m having an issue connecting my Arduino Nano 33 IoT to simulink. When I try to run it, I get the error message: "Unrecognized feild name " HostCOMPort" " I’m unsure how to resolve this and would greatly appricate the help!
The device shows up in my device manager and I can run code in Arduino IDE and Matlab without issues. Its only when I use Simulink is there a problem. Im using the cable that came in the Engineering Rev 2 kit from Arduino as well as a usb to usb-c converter to plug into my surface go to connect my computer to the Nano. I am able to run a regular Arduino Uno using the same setup through simiulink.
I’ve notcied that everytime I try to run the simulink program, the port in the device manager will change from "Arduino Nano 33 IoT" to the bootloader version. And also Matlab will tell me that an arduino device is detected again. My guess is that the Nano is restarting everytime or something? Im not really sure. simulink, arduino, nano MATLAB Answers — New Questions
How can I create an offset of a boundary?
How can I create an offset of a boundary?
rng(‘default’)
x = rand(30,1);
y = rand(30,1);
plot(x,y,’.’)
xlim([-0.2 1.2])
ylim([-0.2 1.2])
k = boundary(x,y);
hold on;
plot(x(k),y(k));
My desired output:How can I create an offset of a boundary?
rng(‘default’)
x = rand(30,1);
y = rand(30,1);
plot(x,y,’.’)
xlim([-0.2 1.2])
ylim([-0.2 1.2])
k = boundary(x,y);
hold on;
plot(x(k),y(k));
My desired output: How can I create an offset of a boundary?
rng(‘default’)
x = rand(30,1);
y = rand(30,1);
plot(x,y,’.’)
xlim([-0.2 1.2])
ylim([-0.2 1.2])
k = boundary(x,y);
hold on;
plot(x(k),y(k));
My desired output: offset, boundary MATLAB Answers — New Questions
How can I control the output data type of the “Signal Editor” block?
How can I control the output data type of the "Signal Editor" block?How can I control the output data type of the "Signal Editor" block? How can I control the output data type of the "Signal Editor" block? signal, editor, simulink, data, types, mat, file, output MATLAB Answers — New Questions
How i get a graph that i attached here with this matlab code?
function HTP()
clc
clear all format long % hybrid Carreau
% Define constants
J1 = 0.1;
J2 = 0.1;
J3 = 0.1;
J4 = 0.1;
JS = 0.1;
z = 0.1;
S = 0.1;
GC = 0.1;
Gr = 0.1;
H = 0.1;
a = 0.1;
m = 1;
G = 0.5;
phi = 0.1;
% Define time vector
t = linspace(0, 5, 100); % 100 points between 0 and 5
%t= 1;
% Calculate u1 and u2
u1 = exp(-t) – 1;
% Compute u2 with corrected parentheses and mathematical operations
exp_t = exp(t); % Compute exp(t) once for efficiency
term1 = -33 / J1 * (1 – exp_t – z / 3 * S);
term2 = 2 * GC * J3 + 2 * Gr * J2;
term3 = (2 * J4 * H * a^2) / (1 + m^2);
term4 = 3 * G * exp_t + 6 * exp_t / ((1 – phi)^2.5);
term5 = 2 * GC * JS * exp_t + 2 * Gr * J2 * exp_t;
u2 = (term1 + term2 – term3 – term4 – term5 + term3 * (exp_t – m + m * exp_t)) / (6 * a);
% Compute u
y = 1; % Define y as 1 or another constant value; adjust as needed
u = u1 * y + u2 * y.^2;
% Plot the result
phi = 0.1
figure ;
plot(t, u);
phi= 0.2
figure ;
plot(t, u);
phi = 0.3
figure ;
plot(t, u);
phi = 0.4
figure ;
plot(t, u);
xlabel(‘Time (t)’);
ylabel(‘u(t)’);
title(‘Plot of u(t)’);
axis([0 5 min(u) max(u)]);
grid on;
endfunction HTP()
clc
clear all format long % hybrid Carreau
% Define constants
J1 = 0.1;
J2 = 0.1;
J3 = 0.1;
J4 = 0.1;
JS = 0.1;
z = 0.1;
S = 0.1;
GC = 0.1;
Gr = 0.1;
H = 0.1;
a = 0.1;
m = 1;
G = 0.5;
phi = 0.1;
% Define time vector
t = linspace(0, 5, 100); % 100 points between 0 and 5
%t= 1;
% Calculate u1 and u2
u1 = exp(-t) – 1;
% Compute u2 with corrected parentheses and mathematical operations
exp_t = exp(t); % Compute exp(t) once for efficiency
term1 = -33 / J1 * (1 – exp_t – z / 3 * S);
term2 = 2 * GC * J3 + 2 * Gr * J2;
term3 = (2 * J4 * H * a^2) / (1 + m^2);
term4 = 3 * G * exp_t + 6 * exp_t / ((1 – phi)^2.5);
term5 = 2 * GC * JS * exp_t + 2 * Gr * J2 * exp_t;
u2 = (term1 + term2 – term3 – term4 – term5 + term3 * (exp_t – m + m * exp_t)) / (6 * a);
% Compute u
y = 1; % Define y as 1 or another constant value; adjust as needed
u = u1 * y + u2 * y.^2;
% Plot the result
phi = 0.1
figure ;
plot(t, u);
phi= 0.2
figure ;
plot(t, u);
phi = 0.3
figure ;
plot(t, u);
phi = 0.4
figure ;
plot(t, u);
xlabel(‘Time (t)’);
ylabel(‘u(t)’);
title(‘Plot of u(t)’);
axis([0 5 min(u) max(u)]);
grid on;
end function HTP()
clc
clear all format long % hybrid Carreau
% Define constants
J1 = 0.1;
J2 = 0.1;
J3 = 0.1;
J4 = 0.1;
JS = 0.1;
z = 0.1;
S = 0.1;
GC = 0.1;
Gr = 0.1;
H = 0.1;
a = 0.1;
m = 1;
G = 0.5;
phi = 0.1;
% Define time vector
t = linspace(0, 5, 100); % 100 points between 0 and 5
%t= 1;
% Calculate u1 and u2
u1 = exp(-t) – 1;
% Compute u2 with corrected parentheses and mathematical operations
exp_t = exp(t); % Compute exp(t) once for efficiency
term1 = -33 / J1 * (1 – exp_t – z / 3 * S);
term2 = 2 * GC * J3 + 2 * Gr * J2;
term3 = (2 * J4 * H * a^2) / (1 + m^2);
term4 = 3 * G * exp_t + 6 * exp_t / ((1 – phi)^2.5);
term5 = 2 * GC * JS * exp_t + 2 * Gr * J2 * exp_t;
u2 = (term1 + term2 – term3 – term4 – term5 + term3 * (exp_t – m + m * exp_t)) / (6 * a);
% Compute u
y = 1; % Define y as 1 or another constant value; adjust as needed
u = u1 * y + u2 * y.^2;
% Plot the result
phi = 0.1
figure ;
plot(t, u);
phi= 0.2
figure ;
plot(t, u);
phi = 0.3
figure ;
plot(t, u);
phi = 0.4
figure ;
plot(t, u);
xlabel(‘Time (t)’);
ylabel(‘u(t)’);
title(‘Plot of u(t)’);
axis([0 5 min(u) max(u)]);
grid on;
end multiple lines in one graph MATLAB Answers — New Questions
write a function called tri_area returns the area of a triangle with base b and height h
hello this is my function code and command window code and there is a message of invalid expression at line 2 and i dont know what is the wrong can anyone help me
function [area] = tri_area([b,h]);
tri_area([b,h])=(0.5)*(b)*(h)
area=tri_area([b,h])
end
%command window
area = tri_area[3,2])hello this is my function code and command window code and there is a message of invalid expression at line 2 and i dont know what is the wrong can anyone help me
function [area] = tri_area([b,h]);
tri_area([b,h])=(0.5)*(b)*(h)
area=tri_area([b,h])
end
%command window
area = tri_area[3,2]) hello this is my function code and command window code and there is a message of invalid expression at line 2 and i dont know what is the wrong can anyone help me
function [area] = tri_area([b,h]);
tri_area([b,h])=(0.5)*(b)*(h)
area=tri_area([b,h])
end
%command window
area = tri_area[3,2]) matlab function, homework MATLAB Answers — New Questions
Copy-pasting variables (values) to edior in 2021b
Copy-pasting column vector values from workspace to editor used to automatically include ; and give me everything in a nicely formated single row. After updating to 2021b it results in a long list of values (each one in a separate row).
For example:
Create a column vector:
> A = [1; 2; 3; 4; 5];
Open it in the workspace, select entire column and copy (ctrl-c)
Paste in the editor results with:
1
2
3
4
5
while it used to result with:
1;2;3;4;5
Is there a way to switch back to the old behavior of copy-pasting variables?
I use it a lot, for example when saving the results in my scripts as starting values for the future and the new format makes the scripts much longer and messier.
Thank you very much in advance for any suggestions.Copy-pasting column vector values from workspace to editor used to automatically include ; and give me everything in a nicely formated single row. After updating to 2021b it results in a long list of values (each one in a separate row).
For example:
Create a column vector:
> A = [1; 2; 3; 4; 5];
Open it in the workspace, select entire column and copy (ctrl-c)
Paste in the editor results with:
1
2
3
4
5
while it used to result with:
1;2;3;4;5
Is there a way to switch back to the old behavior of copy-pasting variables?
I use it a lot, for example when saving the results in my scripts as starting values for the future and the new format makes the scripts much longer and messier.
Thank you very much in advance for any suggestions. Copy-pasting column vector values from workspace to editor used to automatically include ; and give me everything in a nicely formated single row. After updating to 2021b it results in a long list of values (each one in a separate row).
For example:
Create a column vector:
> A = [1; 2; 3; 4; 5];
Open it in the workspace, select entire column and copy (ctrl-c)
Paste in the editor results with:
1
2
3
4
5
while it used to result with:
1;2;3;4;5
Is there a way to switch back to the old behavior of copy-pasting variables?
I use it a lot, for example when saving the results in my scripts as starting values for the future and the new format makes the scripts much longer and messier.
Thank you very much in advance for any suggestions. copy-paste, editor, variables, 2021b update MATLAB Answers — New Questions
appdesigner tab view issue
Hi:
I have an app that showing the tab group at left, I noticed that when the tab name is too long, it will not be fully displayed. I tried to drag the corners of the tab but still not work, as shown in screen shot.
is there anyway to address this issue? i.e. to let the tab names fully shown.
Thanks!
YuHi:
I have an app that showing the tab group at left, I noticed that when the tab name is too long, it will not be fully displayed. I tried to drag the corners of the tab but still not work, as shown in screen shot.
is there anyway to address this issue? i.e. to let the tab names fully shown.
Thanks!
Yu Hi:
I have an app that showing the tab group at left, I noticed that when the tab name is too long, it will not be fully displayed. I tried to drag the corners of the tab but still not work, as shown in screen shot.
is there anyway to address this issue? i.e. to let the tab names fully shown.
Thanks!
Yu appdesigner tab view issue MATLAB Answers — New Questions
PNG Library Filed: Not a PNG File
Image Processing ToolBox, The function "imread" can not identify .png file. Why is this???Image Processing ToolBox, The function "imread" can not identify .png file. Why is this??? Image Processing ToolBox, The function "imread" can not identify .png file. Why is this??? image processing toolbox, imread MATLAB Answers — New Questions
How to solve diffusion equation by the crank – Nicolson method?
I have a diffusion equation 1D:
dC/dt =D*d2C/dx2
with D is changed with time.
Hepl me……
Thank you so much!I have a diffusion equation 1D:
dC/dt =D*d2C/dx2
with D is changed with time.
Hepl me……
Thank you so much! I have a diffusion equation 1D:
dC/dt =D*d2C/dx2
with D is changed with time.
Hepl me……
Thank you so much! MATLAB Answers — New Questions
Why is my model not converging with ode45 solver ?
I am trying to simulate an electronical device that can be modeled by a mass-spring-damper system with an additional non-linear force. The equation at the equilibrium for the system is the following :
The goal of my MATLAB code is to solve this equation for $x$ and find the equilibrium. For this purpose, I use the `ode45` function like this (all coefficient are defined in my code but not shown here) :
x0 = 0;
[t, x] = ode45(@(t, x) odefun(t, x, eps0, a, V0, B, d0, K), tspan, x0);
function dxdt = odefun(t, x, eps, a, V, B, d0, K)
dxdt = ((eps * a * V^2) ./ (2 * B * (d0 – x).^2)) + ((K / B) .* x);
end
The equation is good according to my teachers and several papers but the solver never converges and I can’t see why. All coefficient are defined according to the dimensions of a capacitive micromachined ultrasound transducer. The solution of ode45 is the following :
This is obviously wrong because the dimensions of a cmut are bellow millimeter.
Can you see any mistakes in the way I use the ode45 solver ?
Full code :
% DIMENSIONS DE LA MEMBRANE
e = 500e-9; % epaisseur [m]
r = 20e-6; % rayon [m]
d0 = 550e-9; % epaisseur de cavite [m]
a = pi * r^2; % surface de la membrane [m^2]
% PARAMETRES MECANIQUES
E = 200e9; % module d’Young du SiN [Pa]
nu = 0.25; % coefficient de poisson du SiN
eta = 18.5e-6; % viscosité dynamique de l’air [Pa.s]
p0 = 1e5; % pression exterieure [Pa]
rhoSiN = 3170; % densite du SiN [Kg/m^3]
m = rhoSiN * a * e; % masse membrane [Kg]
K = (16 * E * e^3) / (3 * (1 – nu^2) * r^2); % raideur [N/m]
B = (eta * pi * r^2) / e; % amortissement [N.s/m]
% PARAMETRES ELECTRIQUES
eps0 = 8.85e-12; % permittivité diélectrique du vide [F/m]
V0 = 10; % tension de polarisation [V]
% Conditions initiales et plage de temps
x0 = 0;
ti = 0; tf = 1e-3;
dt = 1e-6;
tspan = linspace(ti, tf, 1/dt);
% Résolution par RK4
[t, x] = ode45(@(t, x) odefun(t, x, eps0, a, V0, B, d0, K), tspan, x0);
plot(t,x,’-‘)
function dxdt = odefun(t, x, eps, a, V, B, d0, K)
dxdt = ((eps * a * V^2) ./ (2 * B * (d0 – x).^2)) + ((K / B) .* x);
end
References :
– Y. Wang, L. -M. He, Z. Li, W. Xu and J. Ren, "A computationally efficient nonlinear dynamic model for cMUT based on COMSOL and MATLAB/Simulink"
– T. Merrien, A. Boulmé and D. Certon, "Lumped-Parameter Equivalent Circuit Modeling of CMUT Array Elements"
I tried several solver from MATLAB and implemented my own Runge-Kutta algorithm based on the Wikipedia example. I also verified the coefficients according to my references.I am trying to simulate an electronical device that can be modeled by a mass-spring-damper system with an additional non-linear force. The equation at the equilibrium for the system is the following :
The goal of my MATLAB code is to solve this equation for $x$ and find the equilibrium. For this purpose, I use the `ode45` function like this (all coefficient are defined in my code but not shown here) :
x0 = 0;
[t, x] = ode45(@(t, x) odefun(t, x, eps0, a, V0, B, d0, K), tspan, x0);
function dxdt = odefun(t, x, eps, a, V, B, d0, K)
dxdt = ((eps * a * V^2) ./ (2 * B * (d0 – x).^2)) + ((K / B) .* x);
end
The equation is good according to my teachers and several papers but the solver never converges and I can’t see why. All coefficient are defined according to the dimensions of a capacitive micromachined ultrasound transducer. The solution of ode45 is the following :
This is obviously wrong because the dimensions of a cmut are bellow millimeter.
Can you see any mistakes in the way I use the ode45 solver ?
Full code :
% DIMENSIONS DE LA MEMBRANE
e = 500e-9; % epaisseur [m]
r = 20e-6; % rayon [m]
d0 = 550e-9; % epaisseur de cavite [m]
a = pi * r^2; % surface de la membrane [m^2]
% PARAMETRES MECANIQUES
E = 200e9; % module d’Young du SiN [Pa]
nu = 0.25; % coefficient de poisson du SiN
eta = 18.5e-6; % viscosité dynamique de l’air [Pa.s]
p0 = 1e5; % pression exterieure [Pa]
rhoSiN = 3170; % densite du SiN [Kg/m^3]
m = rhoSiN * a * e; % masse membrane [Kg]
K = (16 * E * e^3) / (3 * (1 – nu^2) * r^2); % raideur [N/m]
B = (eta * pi * r^2) / e; % amortissement [N.s/m]
% PARAMETRES ELECTRIQUES
eps0 = 8.85e-12; % permittivité diélectrique du vide [F/m]
V0 = 10; % tension de polarisation [V]
% Conditions initiales et plage de temps
x0 = 0;
ti = 0; tf = 1e-3;
dt = 1e-6;
tspan = linspace(ti, tf, 1/dt);
% Résolution par RK4
[t, x] = ode45(@(t, x) odefun(t, x, eps0, a, V0, B, d0, K), tspan, x0);
plot(t,x,’-‘)
function dxdt = odefun(t, x, eps, a, V, B, d0, K)
dxdt = ((eps * a * V^2) ./ (2 * B * (d0 – x).^2)) + ((K / B) .* x);
end
References :
– Y. Wang, L. -M. He, Z. Li, W. Xu and J. Ren, "A computationally efficient nonlinear dynamic model for cMUT based on COMSOL and MATLAB/Simulink"
– T. Merrien, A. Boulmé and D. Certon, "Lumped-Parameter Equivalent Circuit Modeling of CMUT Array Elements"
I tried several solver from MATLAB and implemented my own Runge-Kutta algorithm based on the Wikipedia example. I also verified the coefficients according to my references. I am trying to simulate an electronical device that can be modeled by a mass-spring-damper system with an additional non-linear force. The equation at the equilibrium for the system is the following :
The goal of my MATLAB code is to solve this equation for $x$ and find the equilibrium. For this purpose, I use the `ode45` function like this (all coefficient are defined in my code but not shown here) :
x0 = 0;
[t, x] = ode45(@(t, x) odefun(t, x, eps0, a, V0, B, d0, K), tspan, x0);
function dxdt = odefun(t, x, eps, a, V, B, d0, K)
dxdt = ((eps * a * V^2) ./ (2 * B * (d0 – x).^2)) + ((K / B) .* x);
end
The equation is good according to my teachers and several papers but the solver never converges and I can’t see why. All coefficient are defined according to the dimensions of a capacitive micromachined ultrasound transducer. The solution of ode45 is the following :
This is obviously wrong because the dimensions of a cmut are bellow millimeter.
Can you see any mistakes in the way I use the ode45 solver ?
Full code :
% DIMENSIONS DE LA MEMBRANE
e = 500e-9; % epaisseur [m]
r = 20e-6; % rayon [m]
d0 = 550e-9; % epaisseur de cavite [m]
a = pi * r^2; % surface de la membrane [m^2]
% PARAMETRES MECANIQUES
E = 200e9; % module d’Young du SiN [Pa]
nu = 0.25; % coefficient de poisson du SiN
eta = 18.5e-6; % viscosité dynamique de l’air [Pa.s]
p0 = 1e5; % pression exterieure [Pa]
rhoSiN = 3170; % densite du SiN [Kg/m^3]
m = rhoSiN * a * e; % masse membrane [Kg]
K = (16 * E * e^3) / (3 * (1 – nu^2) * r^2); % raideur [N/m]
B = (eta * pi * r^2) / e; % amortissement [N.s/m]
% PARAMETRES ELECTRIQUES
eps0 = 8.85e-12; % permittivité diélectrique du vide [F/m]
V0 = 10; % tension de polarisation [V]
% Conditions initiales et plage de temps
x0 = 0;
ti = 0; tf = 1e-3;
dt = 1e-6;
tspan = linspace(ti, tf, 1/dt);
% Résolution par RK4
[t, x] = ode45(@(t, x) odefun(t, x, eps0, a, V0, B, d0, K), tspan, x0);
plot(t,x,’-‘)
function dxdt = odefun(t, x, eps, a, V, B, d0, K)
dxdt = ((eps * a * V^2) ./ (2 * B * (d0 – x).^2)) + ((K / B) .* x);
end
References :
– Y. Wang, L. -M. He, Z. Li, W. Xu and J. Ren, "A computationally efficient nonlinear dynamic model for cMUT based on COMSOL and MATLAB/Simulink"
– T. Merrien, A. Boulmé and D. Certon, "Lumped-Parameter Equivalent Circuit Modeling of CMUT Array Elements"
I tried several solver from MATLAB and implemented my own Runge-Kutta algorithm based on the Wikipedia example. I also verified the coefficients according to my references. differential equations, physics, matlab, model, ode45, ode MATLAB Answers — New Questions