Category: Matlab
Category Archives: Matlab
What is the ratio of area of the flame between the last frame and the first? What is wrong with my approach? I am getting an incorrect answer upon submission.
Question 3 Create a mask for each frame of this video that isolates the nearly-white flame exiting the rocket. Do this by converting each frame to grayscale. Then label all pixels with intensities less than or equal to 245 as false, and all pixels with intensities greater than 245 as true.
What is the ratio of area of the flame between the last frame and the first? (Use the number of true pixels for area.)
% Load the video file ‘shuttle.avi’
videoFile = ‘shuttle.avi’;
v = VideoReader(videoFile);
% Read the first frame
firstFrame = readFrame(v);
% Move to the last frame
while hasFrame(v)
lastFrame = readFrame(v);
end
% Convert both frames to grayscale
firstGray = rgb2gray(firstFrame);
lastGray = rgb2gray(lastFrame);
% Create masks where pixel intensities > 245 are true, the rest are false
firstMask = firstGray > 245;
lastMask = lastGray > 245;
% Calculate the flame area (number of ‘true’ pixels) for both frames
areaFirst = sum(firstMask(:));
areaLast = sum(lastMask(:));
% Calculate the ratio of the flame area between the last and the first frame
if areaFirst == 0
error(‘No flame detected in the first frame.’);
else
ratio = areaLast / areaFirst;
end
% Display the results
fprintf(‘Area of the flame in the first frame: %d pixelsn’, areaFirst);
fprintf(‘Area of the flame in the last frame: %d pixelsn’, areaLast);
fprintf(‘Ratio of flame area (last frame / first frame): %.2fn’, ratio);
% Optional: Display the original frames and the masks for visual verification
figure;
subplot(2,2,1), imshow(firstFrame), title(‘First Frame’);
subplot(2,2,2), imshow(lastFrame), title(‘Last Frame’);
subplot(2,2,3), imshow(firstMask), title(‘First Frame Mask’);
subplot(2,2,4), imshow(lastMask), title(‘Last Frame Mask’);Question 3 Create a mask for each frame of this video that isolates the nearly-white flame exiting the rocket. Do this by converting each frame to grayscale. Then label all pixels with intensities less than or equal to 245 as false, and all pixels with intensities greater than 245 as true.
What is the ratio of area of the flame between the last frame and the first? (Use the number of true pixels for area.)
% Load the video file ‘shuttle.avi’
videoFile = ‘shuttle.avi’;
v = VideoReader(videoFile);
% Read the first frame
firstFrame = readFrame(v);
% Move to the last frame
while hasFrame(v)
lastFrame = readFrame(v);
end
% Convert both frames to grayscale
firstGray = rgb2gray(firstFrame);
lastGray = rgb2gray(lastFrame);
% Create masks where pixel intensities > 245 are true, the rest are false
firstMask = firstGray > 245;
lastMask = lastGray > 245;
% Calculate the flame area (number of ‘true’ pixels) for both frames
areaFirst = sum(firstMask(:));
areaLast = sum(lastMask(:));
% Calculate the ratio of the flame area between the last and the first frame
if areaFirst == 0
error(‘No flame detected in the first frame.’);
else
ratio = areaLast / areaFirst;
end
% Display the results
fprintf(‘Area of the flame in the first frame: %d pixelsn’, areaFirst);
fprintf(‘Area of the flame in the last frame: %d pixelsn’, areaLast);
fprintf(‘Ratio of flame area (last frame / first frame): %.2fn’, ratio);
% Optional: Display the original frames and the masks for visual verification
figure;
subplot(2,2,1), imshow(firstFrame), title(‘First Frame’);
subplot(2,2,2), imshow(lastFrame), title(‘Last Frame’);
subplot(2,2,3), imshow(firstMask), title(‘First Frame Mask’);
subplot(2,2,4), imshow(lastMask), title(‘Last Frame Mask’); Question 3 Create a mask for each frame of this video that isolates the nearly-white flame exiting the rocket. Do this by converting each frame to grayscale. Then label all pixels with intensities less than or equal to 245 as false, and all pixels with intensities greater than 245 as true.
What is the ratio of area of the flame between the last frame and the first? (Use the number of true pixels for area.)
% Load the video file ‘shuttle.avi’
videoFile = ‘shuttle.avi’;
v = VideoReader(videoFile);
% Read the first frame
firstFrame = readFrame(v);
% Move to the last frame
while hasFrame(v)
lastFrame = readFrame(v);
end
% Convert both frames to grayscale
firstGray = rgb2gray(firstFrame);
lastGray = rgb2gray(lastFrame);
% Create masks where pixel intensities > 245 are true, the rest are false
firstMask = firstGray > 245;
lastMask = lastGray > 245;
% Calculate the flame area (number of ‘true’ pixels) for both frames
areaFirst = sum(firstMask(:));
areaLast = sum(lastMask(:));
% Calculate the ratio of the flame area between the last and the first frame
if areaFirst == 0
error(‘No flame detected in the first frame.’);
else
ratio = areaLast / areaFirst;
end
% Display the results
fprintf(‘Area of the flame in the first frame: %d pixelsn’, areaFirst);
fprintf(‘Area of the flame in the last frame: %d pixelsn’, areaLast);
fprintf(‘Ratio of flame area (last frame / first frame): %.2fn’, ratio);
% Optional: Display the original frames and the masks for visual verification
figure;
subplot(2,2,1), imshow(firstFrame), title(‘First Frame’);
subplot(2,2,2), imshow(lastFrame), title(‘Last Frame’);
subplot(2,2,3), imshow(firstMask), title(‘First Frame Mask’);
subplot(2,2,4), imshow(lastMask), title(‘Last Frame Mask’); image processing MATLAB Answers — New Questions
How to know what version of MKL is MATLAB using
Hi:
I am using MATLAB R2010b. I would like to know the version (I think there is a command but I don’t remember it) to know what version of MKL (Math Kernel Library) is MATLAB using.
Thank you very muchHi:
I am using MATLAB R2010b. I would like to know the version (I think there is a command but I don’t remember it) to know what version of MKL (Math Kernel Library) is MATLAB using.
Thank you very much Hi:
I am using MATLAB R2010b. I would like to know the version (I think there is a command but I don’t remember it) to know what version of MKL (Math Kernel Library) is MATLAB using.
Thank you very much mkl matlab MATLAB Answers — New Questions
Creating a Code to determine Lift Curve Slope
For an Aerodynamics couse, we need to create a code that computes lifting surfaces (wing) aerodynamics. I cannot get the graph to display a nice CL vs AoA curve, but only a single value. I don’t know how I can accomplish this. As I am a novice to MAtlab, I would appreciate some pointers or hints. Thank you.
clc;
% Default airfoil or not…
Default_AF = 0;
% A/F Characteristics:
% Lift coefficient [1/rad]:
Cl_alpha = 5.79;
Cl_alphaInRadians = deg2rad(Cl_alpha);
% Sectional lift curve slope [deg]:
alpha_0 = -2.0;
% Pitching moment [1/rad]:
Cm_alpha = 0;
Cm_alphaInRadians = deg2rad(Cm_alpha);
% 2D Pitching moment:
Cm_0 = -0.025;
% Coefficient in series expansion of circulation distribution [deg]:
alpha_nl = 8;
% Wing planform Geometry [inches]:
% [root-LE,root-TE,tip-LE,tip-TE]
x1 = 0;
y1 = 0;
x2 = 200;
y2 = 0;
x3 = 0;
y3 = 1000;
x4 = 200;
y4 = 1000;
% Wing twist angle [deg]:
theta_t = 0;
% Number of spanwise coefficients:
N = 100;
% Flight Conditions:
% Free-stream Velocity [ft/sec]
V = 100;
% Density [slugs/ft^3]:
rho = 0.002344;
% Viscous Force [lb.s/ft^2]
mu = 0.0000003737;
% Angle of Attack [deg]
alpha = 5;
% Wing span:
b = sqrt((x2-x1)^2 + (y2-y1)^2);
% Wing chord:
c = sqrt((x3-x1)^2 + (y3-y1)^2);
% Wing area:
S = b*c;
% Wing semi-span:
s = b/2;
% Aspect Ratio:
AR = b^2./S;
% Applying segment length of the wings:
alpha_segment = zeros(1,N);
theta_segment = zeros(1,N);
% Taper Ratio and its range within the wing (which is 0 to 1):
for lambda_r = 0:0.25:1
% Root Chord:
c_root = (2*S) / ((1+lambda_r)*b);
% Tip Chord:
c_tip = ((2*S)/((1+lambda_r)*b)) * (1-((2*(1-lambda_r))/b)*(b/2));
% Mean Aerodynamic Chord:
MAC = (2/3)*(c_root+c_tip-(c_root*c_tip)/(c_root+c_tip));
% Taper ratio:
lambda = c_tip / c_root;
% Providing segment limitation within range:
alpha_segment(1) = alpha;
theta_segment(1) = pi/2;
% Completing the Lifting Line Theory to determine the
% matrix value of the segments:
for N = 2:N
c(N) = c_root+(c_tip-c_root)/N.*N;
alpha_segment(N) = alpha+(theta_t)/N.*N;
theta_segment = pi/(2*N):pi/(2*N):pi/2;
end
% Lifting line theory construction:
xb = 4*b./(pi*c);
% Completing the [B] matrix:
for i = 1:N
for j = 1:N
B(i,j) = (sin(j.*theta_segment(i))).*(xb(i)+j/(sin(theta_segment(i))));
end
slope(i) = (alpha_segment(i)-alpha_0)*(pi/180);
end
A = Btranspose(slope);
end
% Leading edge sweep angle
for fai = 1:N
delta_LE(fai) = fai*(A(fai)/A(1))^2; %#ok<*SAGROW>
end
% Section Lift Coefficient of Airfoil
cl = 0.5*cos(pi/b);
% Wing Lift Coefficient:
CL = pi*AR*A(1);
% Span Efficiency:
delta = sum(delta_LE);
CD_0 = 1/(1+delta);
% Induced drag coefficient:
CD_i = CL.^2 / (pi*CD_0*AR);
% Speed of sound (assuming 20 degree dry air) [ft/sec]:
C = 1125.33;
% Mach Number:
M = V / C;
% Dynamic Pressure:
q = (0.5*rho*V^2);
% Pitching Moment Coefficient:
CM = M / q*S*c;
% Subsonic Lift:
alpha_inf = 2*pi*cos(delta_LE);
% 3D Lift Curve Slope of airfoil:
CL_alpha = 2*pi*A;
% Geometric Angle of Attack of Wing:
alpha = (alpha_inf)/(1+(alpha_inf)/(pi*AR));
%———————————————————-
% Wing lift coefficient (CL) vs Angle of Attack (alpha):
figure(1);
plot(alpha,CL,’-o’)
grid on
title(‘Wing lift coefficient (CL) vs Angle of Attack (alpha)’)
ylabel(‘Wing Lift Coefficient, CL’)
xlabel(‘Angle of Attack, alpha [deg]’)
% Pitching moment coefficient(CM) vs Angle of Attack (alpha):
figure(2);
plot(alpha,CM,’-o’)
grid on
title(‘Pitching moment coefficient(CM) vs Angle of Attack (alpha)’)
ylabel(‘Pitching Moment Coefficient, CM’)
xlabel(‘Angle of Attack, alpha [deg]’)
% Wing lift coefficient (CL) vs Induced drag coefficient (CD_i):
figure(3);
plot(CD_i,CL,’-o’)
grid on
title(‘Wing lift coefficient (CL) vs Induced drag coefficient (CD_i)’)
ylabel(‘Wing Lift Coefficient, CL’)
xlabel(‘Induced Drag Coefficient, CD_i’)For an Aerodynamics couse, we need to create a code that computes lifting surfaces (wing) aerodynamics. I cannot get the graph to display a nice CL vs AoA curve, but only a single value. I don’t know how I can accomplish this. As I am a novice to MAtlab, I would appreciate some pointers or hints. Thank you.
clc;
% Default airfoil or not…
Default_AF = 0;
% A/F Characteristics:
% Lift coefficient [1/rad]:
Cl_alpha = 5.79;
Cl_alphaInRadians = deg2rad(Cl_alpha);
% Sectional lift curve slope [deg]:
alpha_0 = -2.0;
% Pitching moment [1/rad]:
Cm_alpha = 0;
Cm_alphaInRadians = deg2rad(Cm_alpha);
% 2D Pitching moment:
Cm_0 = -0.025;
% Coefficient in series expansion of circulation distribution [deg]:
alpha_nl = 8;
% Wing planform Geometry [inches]:
% [root-LE,root-TE,tip-LE,tip-TE]
x1 = 0;
y1 = 0;
x2 = 200;
y2 = 0;
x3 = 0;
y3 = 1000;
x4 = 200;
y4 = 1000;
% Wing twist angle [deg]:
theta_t = 0;
% Number of spanwise coefficients:
N = 100;
% Flight Conditions:
% Free-stream Velocity [ft/sec]
V = 100;
% Density [slugs/ft^3]:
rho = 0.002344;
% Viscous Force [lb.s/ft^2]
mu = 0.0000003737;
% Angle of Attack [deg]
alpha = 5;
% Wing span:
b = sqrt((x2-x1)^2 + (y2-y1)^2);
% Wing chord:
c = sqrt((x3-x1)^2 + (y3-y1)^2);
% Wing area:
S = b*c;
% Wing semi-span:
s = b/2;
% Aspect Ratio:
AR = b^2./S;
% Applying segment length of the wings:
alpha_segment = zeros(1,N);
theta_segment = zeros(1,N);
% Taper Ratio and its range within the wing (which is 0 to 1):
for lambda_r = 0:0.25:1
% Root Chord:
c_root = (2*S) / ((1+lambda_r)*b);
% Tip Chord:
c_tip = ((2*S)/((1+lambda_r)*b)) * (1-((2*(1-lambda_r))/b)*(b/2));
% Mean Aerodynamic Chord:
MAC = (2/3)*(c_root+c_tip-(c_root*c_tip)/(c_root+c_tip));
% Taper ratio:
lambda = c_tip / c_root;
% Providing segment limitation within range:
alpha_segment(1) = alpha;
theta_segment(1) = pi/2;
% Completing the Lifting Line Theory to determine the
% matrix value of the segments:
for N = 2:N
c(N) = c_root+(c_tip-c_root)/N.*N;
alpha_segment(N) = alpha+(theta_t)/N.*N;
theta_segment = pi/(2*N):pi/(2*N):pi/2;
end
% Lifting line theory construction:
xb = 4*b./(pi*c);
% Completing the [B] matrix:
for i = 1:N
for j = 1:N
B(i,j) = (sin(j.*theta_segment(i))).*(xb(i)+j/(sin(theta_segment(i))));
end
slope(i) = (alpha_segment(i)-alpha_0)*(pi/180);
end
A = Btranspose(slope);
end
% Leading edge sweep angle
for fai = 1:N
delta_LE(fai) = fai*(A(fai)/A(1))^2; %#ok<*SAGROW>
end
% Section Lift Coefficient of Airfoil
cl = 0.5*cos(pi/b);
% Wing Lift Coefficient:
CL = pi*AR*A(1);
% Span Efficiency:
delta = sum(delta_LE);
CD_0 = 1/(1+delta);
% Induced drag coefficient:
CD_i = CL.^2 / (pi*CD_0*AR);
% Speed of sound (assuming 20 degree dry air) [ft/sec]:
C = 1125.33;
% Mach Number:
M = V / C;
% Dynamic Pressure:
q = (0.5*rho*V^2);
% Pitching Moment Coefficient:
CM = M / q*S*c;
% Subsonic Lift:
alpha_inf = 2*pi*cos(delta_LE);
% 3D Lift Curve Slope of airfoil:
CL_alpha = 2*pi*A;
% Geometric Angle of Attack of Wing:
alpha = (alpha_inf)/(1+(alpha_inf)/(pi*AR));
%———————————————————-
% Wing lift coefficient (CL) vs Angle of Attack (alpha):
figure(1);
plot(alpha,CL,’-o’)
grid on
title(‘Wing lift coefficient (CL) vs Angle of Attack (alpha)’)
ylabel(‘Wing Lift Coefficient, CL’)
xlabel(‘Angle of Attack, alpha [deg]’)
% Pitching moment coefficient(CM) vs Angle of Attack (alpha):
figure(2);
plot(alpha,CM,’-o’)
grid on
title(‘Pitching moment coefficient(CM) vs Angle of Attack (alpha)’)
ylabel(‘Pitching Moment Coefficient, CM’)
xlabel(‘Angle of Attack, alpha [deg]’)
% Wing lift coefficient (CL) vs Induced drag coefficient (CD_i):
figure(3);
plot(CD_i,CL,’-o’)
grid on
title(‘Wing lift coefficient (CL) vs Induced drag coefficient (CD_i)’)
ylabel(‘Wing Lift Coefficient, CL’)
xlabel(‘Induced Drag Coefficient, CD_i’) For an Aerodynamics couse, we need to create a code that computes lifting surfaces (wing) aerodynamics. I cannot get the graph to display a nice CL vs AoA curve, but only a single value. I don’t know how I can accomplish this. As I am a novice to MAtlab, I would appreciate some pointers or hints. Thank you.
clc;
% Default airfoil or not…
Default_AF = 0;
% A/F Characteristics:
% Lift coefficient [1/rad]:
Cl_alpha = 5.79;
Cl_alphaInRadians = deg2rad(Cl_alpha);
% Sectional lift curve slope [deg]:
alpha_0 = -2.0;
% Pitching moment [1/rad]:
Cm_alpha = 0;
Cm_alphaInRadians = deg2rad(Cm_alpha);
% 2D Pitching moment:
Cm_0 = -0.025;
% Coefficient in series expansion of circulation distribution [deg]:
alpha_nl = 8;
% Wing planform Geometry [inches]:
% [root-LE,root-TE,tip-LE,tip-TE]
x1 = 0;
y1 = 0;
x2 = 200;
y2 = 0;
x3 = 0;
y3 = 1000;
x4 = 200;
y4 = 1000;
% Wing twist angle [deg]:
theta_t = 0;
% Number of spanwise coefficients:
N = 100;
% Flight Conditions:
% Free-stream Velocity [ft/sec]
V = 100;
% Density [slugs/ft^3]:
rho = 0.002344;
% Viscous Force [lb.s/ft^2]
mu = 0.0000003737;
% Angle of Attack [deg]
alpha = 5;
% Wing span:
b = sqrt((x2-x1)^2 + (y2-y1)^2);
% Wing chord:
c = sqrt((x3-x1)^2 + (y3-y1)^2);
% Wing area:
S = b*c;
% Wing semi-span:
s = b/2;
% Aspect Ratio:
AR = b^2./S;
% Applying segment length of the wings:
alpha_segment = zeros(1,N);
theta_segment = zeros(1,N);
% Taper Ratio and its range within the wing (which is 0 to 1):
for lambda_r = 0:0.25:1
% Root Chord:
c_root = (2*S) / ((1+lambda_r)*b);
% Tip Chord:
c_tip = ((2*S)/((1+lambda_r)*b)) * (1-((2*(1-lambda_r))/b)*(b/2));
% Mean Aerodynamic Chord:
MAC = (2/3)*(c_root+c_tip-(c_root*c_tip)/(c_root+c_tip));
% Taper ratio:
lambda = c_tip / c_root;
% Providing segment limitation within range:
alpha_segment(1) = alpha;
theta_segment(1) = pi/2;
% Completing the Lifting Line Theory to determine the
% matrix value of the segments:
for N = 2:N
c(N) = c_root+(c_tip-c_root)/N.*N;
alpha_segment(N) = alpha+(theta_t)/N.*N;
theta_segment = pi/(2*N):pi/(2*N):pi/2;
end
% Lifting line theory construction:
xb = 4*b./(pi*c);
% Completing the [B] matrix:
for i = 1:N
for j = 1:N
B(i,j) = (sin(j.*theta_segment(i))).*(xb(i)+j/(sin(theta_segment(i))));
end
slope(i) = (alpha_segment(i)-alpha_0)*(pi/180);
end
A = Btranspose(slope);
end
% Leading edge sweep angle
for fai = 1:N
delta_LE(fai) = fai*(A(fai)/A(1))^2; %#ok<*SAGROW>
end
% Section Lift Coefficient of Airfoil
cl = 0.5*cos(pi/b);
% Wing Lift Coefficient:
CL = pi*AR*A(1);
% Span Efficiency:
delta = sum(delta_LE);
CD_0 = 1/(1+delta);
% Induced drag coefficient:
CD_i = CL.^2 / (pi*CD_0*AR);
% Speed of sound (assuming 20 degree dry air) [ft/sec]:
C = 1125.33;
% Mach Number:
M = V / C;
% Dynamic Pressure:
q = (0.5*rho*V^2);
% Pitching Moment Coefficient:
CM = M / q*S*c;
% Subsonic Lift:
alpha_inf = 2*pi*cos(delta_LE);
% 3D Lift Curve Slope of airfoil:
CL_alpha = 2*pi*A;
% Geometric Angle of Attack of Wing:
alpha = (alpha_inf)/(1+(alpha_inf)/(pi*AR));
%———————————————————-
% Wing lift coefficient (CL) vs Angle of Attack (alpha):
figure(1);
plot(alpha,CL,’-o’)
grid on
title(‘Wing lift coefficient (CL) vs Angle of Attack (alpha)’)
ylabel(‘Wing Lift Coefficient, CL’)
xlabel(‘Angle of Attack, alpha [deg]’)
% Pitching moment coefficient(CM) vs Angle of Attack (alpha):
figure(2);
plot(alpha,CM,’-o’)
grid on
title(‘Pitching moment coefficient(CM) vs Angle of Attack (alpha)’)
ylabel(‘Pitching Moment Coefficient, CM’)
xlabel(‘Angle of Attack, alpha [deg]’)
% Wing lift coefficient (CL) vs Induced drag coefficient (CD_i):
figure(3);
plot(CD_i,CL,’-o’)
grid on
title(‘Wing lift coefficient (CL) vs Induced drag coefficient (CD_i)’)
ylabel(‘Wing Lift Coefficient, CL’)
xlabel(‘Induced Drag Coefficient, CD_i’) aerodynamics, lifting surfaces MATLAB Answers — New Questions
4. f(x)=x^2/3(3-x^2)(x-4). how do i enter this function in matlab.
When I input the above function as x^(2/3)*(3-x^2)*(x-4) in a code where i have to find extrema , maxima and critical points for a given function , i am getting error which says
Warning: Solutions are parameterized by the symbols: z2. To include parameters and conditions in the solution, specify the ‘ReturnConditions’
value as ‘true’.
Error using mupadengine/feval2char
Unable to convert expression containing symbolic variables into double array. Apply ‘subs’ function first to substitute values for variables.
Error in sym/double (line 755)
Xstr = feval2char(symengine, "symobj::double", S);
however the same cose is working if I input some other functionWhen I input the above function as x^(2/3)*(3-x^2)*(x-4) in a code where i have to find extrema , maxima and critical points for a given function , i am getting error which says
Warning: Solutions are parameterized by the symbols: z2. To include parameters and conditions in the solution, specify the ‘ReturnConditions’
value as ‘true’.
Error using mupadengine/feval2char
Unable to convert expression containing symbolic variables into double array. Apply ‘subs’ function first to substitute values for variables.
Error in sym/double (line 755)
Xstr = feval2char(symengine, "symobj::double", S);
however the same cose is working if I input some other function When I input the above function as x^(2/3)*(3-x^2)*(x-4) in a code where i have to find extrema , maxima and critical points for a given function , i am getting error which says
Warning: Solutions are parameterized by the symbols: z2. To include parameters and conditions in the solution, specify the ‘ReturnConditions’
value as ‘true’.
Error using mupadengine/feval2char
Unable to convert expression containing symbolic variables into double array. Apply ‘subs’ function first to substitute values for variables.
Error in sym/double (line 755)
Xstr = feval2char(symengine, "symobj::double", S);
however the same cose is working if I input some other function please do clear this problem MATLAB Answers — New Questions
Why do I get a blank SSO screen when attempting to sign in to MATLAB at start up?
I was able to install MATLAB, however I am not able to sign into my MathWorks Account with my university credentials when trying to launch MATLAB for the first time.
When I input my email address it says I must log in through my school’s portal, but nothing pops up except a blank white page in my shortcut.
I was able to install MATLAB, however I am not able to sign into my MathWorks Account with my university credentials when trying to launch MATLAB for the first time.
When I input my email address it says I must log in through my school’s portal, but nothing pops up except a blank white page in my shortcut.
I was able to install MATLAB, however I am not able to sign into my MathWorks Account with my university credentials when trying to launch MATLAB for the first time.
When I input my email address it says I must log in through my school’s portal, but nothing pops up except a blank white page in my shortcut.
MATLAB Answers — New Questions
Determine the direction of travelling waves in Fourier Analysis
% I am conducting a FFT analysis and i I observed that there is travelling
% wave. Please, how do I determine the direction of the travelling waves?
% Compute the phase of the FFT: theta_phase = angle(Ytheta);
% Compute the mean phase difference: p = polyfit(f, theta_phase, 1);
% slope = p(1); % The slope of the phase vs. frequency plot
% Store the mean phase difference: mean_phase_diff(i) = slope;
% Then I test the mean_phase_diff(i) > 0 implies rightward direction or if
% mean_phase_diff(i) < 0 leftward direction. I am wondering if there is a
% better way or function to do this.
clear
%close all
pars.W = 20e-6;
pars.D = 2e-6;
% time discretisation – start, step and end
t = 0:0.025:5;
% Extract theta data
loaded_data = load(‘thetam.mat’);
thetam = loaded_data.thetam;
% Sample frequency
Fs = 1/(t(2) – t(1));
% Number of samples
L = length(t);
% Number of ramp slopes
num_ramp_slopes = size(thetam, 1);
% Frequency vector for FFT
f = (-L/2 : L/2-1) * (Fs / L);
% Loop through each ramp_slope
for i = 1:num_ramp_slopes
% Extract the theta data for the current ramp_slope
theta_data = thetam(i, :);
% Compute the FFT of the theta data
Ytheta = fft(theta_data);
% Shift zero frequency component to center
Ytheta = fftshift(Ytheta);
end
% Plot the magnitude of the FFT for the first ramp_slope
fig1 = figure;
plot(f, abs(fftshift(fft(thetam(1, :)))), ‘LineWidth’, 0.8);
xlabel(‘Frequency (Hz)’);
ylabel(‘Magnitude’);
title(‘FFT Magnitude for Ramp Slope 1’);
xlim([-Fs/2 Fs/2]);
grid on;% I am conducting a FFT analysis and i I observed that there is travelling
% wave. Please, how do I determine the direction of the travelling waves?
% Compute the phase of the FFT: theta_phase = angle(Ytheta);
% Compute the mean phase difference: p = polyfit(f, theta_phase, 1);
% slope = p(1); % The slope of the phase vs. frequency plot
% Store the mean phase difference: mean_phase_diff(i) = slope;
% Then I test the mean_phase_diff(i) > 0 implies rightward direction or if
% mean_phase_diff(i) < 0 leftward direction. I am wondering if there is a
% better way or function to do this.
clear
%close all
pars.W = 20e-6;
pars.D = 2e-6;
% time discretisation – start, step and end
t = 0:0.025:5;
% Extract theta data
loaded_data = load(‘thetam.mat’);
thetam = loaded_data.thetam;
% Sample frequency
Fs = 1/(t(2) – t(1));
% Number of samples
L = length(t);
% Number of ramp slopes
num_ramp_slopes = size(thetam, 1);
% Frequency vector for FFT
f = (-L/2 : L/2-1) * (Fs / L);
% Loop through each ramp_slope
for i = 1:num_ramp_slopes
% Extract the theta data for the current ramp_slope
theta_data = thetam(i, :);
% Compute the FFT of the theta data
Ytheta = fft(theta_data);
% Shift zero frequency component to center
Ytheta = fftshift(Ytheta);
end
% Plot the magnitude of the FFT for the first ramp_slope
fig1 = figure;
plot(f, abs(fftshift(fft(thetam(1, :)))), ‘LineWidth’, 0.8);
xlabel(‘Frequency (Hz)’);
ylabel(‘Magnitude’);
title(‘FFT Magnitude for Ramp Slope 1’);
xlim([-Fs/2 Fs/2]);
grid on; % I am conducting a FFT analysis and i I observed that there is travelling
% wave. Please, how do I determine the direction of the travelling waves?
% Compute the phase of the FFT: theta_phase = angle(Ytheta);
% Compute the mean phase difference: p = polyfit(f, theta_phase, 1);
% slope = p(1); % The slope of the phase vs. frequency plot
% Store the mean phase difference: mean_phase_diff(i) = slope;
% Then I test the mean_phase_diff(i) > 0 implies rightward direction or if
% mean_phase_diff(i) < 0 leftward direction. I am wondering if there is a
% better way or function to do this.
clear
%close all
pars.W = 20e-6;
pars.D = 2e-6;
% time discretisation – start, step and end
t = 0:0.025:5;
% Extract theta data
loaded_data = load(‘thetam.mat’);
thetam = loaded_data.thetam;
% Sample frequency
Fs = 1/(t(2) – t(1));
% Number of samples
L = length(t);
% Number of ramp slopes
num_ramp_slopes = size(thetam, 1);
% Frequency vector for FFT
f = (-L/2 : L/2-1) * (Fs / L);
% Loop through each ramp_slope
for i = 1:num_ramp_slopes
% Extract the theta data for the current ramp_slope
theta_data = thetam(i, :);
% Compute the FFT of the theta data
Ytheta = fft(theta_data);
% Shift zero frequency component to center
Ytheta = fftshift(Ytheta);
end
% Plot the magnitude of the FFT for the first ramp_slope
fig1 = figure;
plot(f, abs(fftshift(fft(thetam(1, :)))), ‘LineWidth’, 0.8);
xlabel(‘Frequency (Hz)’);
ylabel(‘Magnitude’);
title(‘FFT Magnitude for Ramp Slope 1’);
xlim([-Fs/2 Fs/2]);
grid on; wave direction, fourier series, fft MATLAB Answers — New Questions
how can I take Dynamic Voltage Restorer Block from library browser in matlab simulink ?
I am searching the Dynamic Voltage Restorer (DVR) block in library browser but I am not getting the block.please provide me the steps to find out the DVR block from library browser in matlab simulink.I am searching the Dynamic Voltage Restorer (DVR) block in library browser but I am not getting the block.please provide me the steps to find out the DVR block from library browser in matlab simulink. I am searching the Dynamic Voltage Restorer (DVR) block in library browser but I am not getting the block.please provide me the steps to find out the DVR block from library browser in matlab simulink. dvr MATLAB Answers — New Questions
how to fuse two png images with equal tranparency and with proper positioning in the final image?
Hello there,
I need to mix two pictures in a way so that one is placed over the other. But both should have equal transparency. Also the location of the first picture over the second should be determinable. is there any way we can do this using imfuse or any other function in MATLAB? whenevr I use this script one gets faded and is located in one of the corners which are not desirable. Can we fix this?Hello there,
I need to mix two pictures in a way so that one is placed over the other. But both should have equal transparency. Also the location of the first picture over the second should be determinable. is there any way we can do this using imfuse or any other function in MATLAB? whenevr I use this script one gets faded and is located in one of the corners which are not desirable. Can we fix this? Hello there,
I need to mix two pictures in a way so that one is placed over the other. But both should have equal transparency. Also the location of the first picture over the second should be determinable. is there any way we can do this using imfuse or any other function in MATLAB? whenevr I use this script one gets faded and is located in one of the corners which are not desirable. Can we fix this? imfuse, transparency, blend MATLAB Answers — New Questions
How to obtain the State Transition Matrix from Simscape Multibody model?
I need to include the Dynamic of the robot I’m using, imported from an URDF file, to a Extended Kalman Filter as the State Transition Function in order to estimate the states of the system. I tried to put all the simscape model inside a Simulink Function, but it brings Error1 saying I can’t put the solver configuration block (from the robot’s body tree) inside a subsystem. I came back and also tried taking the solver configuration block out of the Simulink Function and brin it in using a Connection Port, but it sends now Error2 saying all the elements of the body tree must be in the same level.
Error1: "’brazo_2dof/Simulink Function/Solver Configuration’ has been placed in the function call subsystem ‘brazo_2dof/Simulink Function’ but does not support this configuration. Move the block out of the function call subsystem."
Error2: "Connections of the Physical Network cross nonvirtual boundaries. If any blocks in a Physical Network are within a nonvirtual subsystem, then all blocks of that network must be in the same nonvirtual subsystem. Either move affected blocks out of the nonvirtual subsystem, move network blocks into exactly one nonvirtual subsystem, or reconfigure affected nonvirtual subsystems to be virtual subsystems."
How else could I include the dynamics of my system, imported from the URDF, as the StateTransitionFunction?I need to include the Dynamic of the robot I’m using, imported from an URDF file, to a Extended Kalman Filter as the State Transition Function in order to estimate the states of the system. I tried to put all the simscape model inside a Simulink Function, but it brings Error1 saying I can’t put the solver configuration block (from the robot’s body tree) inside a subsystem. I came back and also tried taking the solver configuration block out of the Simulink Function and brin it in using a Connection Port, but it sends now Error2 saying all the elements of the body tree must be in the same level.
Error1: "’brazo_2dof/Simulink Function/Solver Configuration’ has been placed in the function call subsystem ‘brazo_2dof/Simulink Function’ but does not support this configuration. Move the block out of the function call subsystem."
Error2: "Connections of the Physical Network cross nonvirtual boundaries. If any blocks in a Physical Network are within a nonvirtual subsystem, then all blocks of that network must be in the same nonvirtual subsystem. Either move affected blocks out of the nonvirtual subsystem, move network blocks into exactly one nonvirtual subsystem, or reconfigure affected nonvirtual subsystems to be virtual subsystems."
How else could I include the dynamics of my system, imported from the URDF, as the StateTransitionFunction? I need to include the Dynamic of the robot I’m using, imported from an URDF file, to a Extended Kalman Filter as the State Transition Function in order to estimate the states of the system. I tried to put all the simscape model inside a Simulink Function, but it brings Error1 saying I can’t put the solver configuration block (from the robot’s body tree) inside a subsystem. I came back and also tried taking the solver configuration block out of the Simulink Function and brin it in using a Connection Port, but it sends now Error2 saying all the elements of the body tree must be in the same level.
Error1: "’brazo_2dof/Simulink Function/Solver Configuration’ has been placed in the function call subsystem ‘brazo_2dof/Simulink Function’ but does not support this configuration. Move the block out of the function call subsystem."
Error2: "Connections of the Physical Network cross nonvirtual boundaries. If any blocks in a Physical Network are within a nonvirtual subsystem, then all blocks of that network must be in the same nonvirtual subsystem. Either move affected blocks out of the nonvirtual subsystem, move network blocks into exactly one nonvirtual subsystem, or reconfigure affected nonvirtual subsystems to be virtual subsystems."
How else could I include the dynamics of my system, imported from the URDF, as the StateTransitionFunction? simscape, extended kalman filter, state transition function, multibody, estimate states MATLAB Answers — New Questions
I want to create a following matrix using nested loops
Matrix[1,2,3,4,5;2,4,7,11,16;3,7,14,25,41] Here every row has different logic.How do I use for loop?Matrix[1,2,3,4,5;2,4,7,11,16;3,7,14,25,41] Here every row has different logic.How do I use for loop? Matrix[1,2,3,4,5;2,4,7,11,16;3,7,14,25,41] Here every row has different logic.How do I use for loop? #nestedloop #matrix MATLAB Answers — New Questions
Organization Sign-in portal not popping up
When I try to open Matlab Desktop 2024a it asks me to sign in and when i type my email it says "Sign into your organization’s portal to proceed." but there is not Organization portal popping up for me to sign inWhen I try to open Matlab Desktop 2024a it asks me to sign in and when i type my email it says "Sign into your organization’s portal to proceed." but there is not Organization portal popping up for me to sign in When I try to open Matlab Desktop 2024a it asks me to sign in and when i type my email it says "Sign into your organization’s portal to proceed." but there is not Organization portal popping up for me to sign in login, sign-in MATLAB Answers — New Questions
Extracting metrics from cellular pattern
I’m trying to determine the width, height, area, and centroid of an scaly pattern shown in the attached image. I’ve tried using a gradient filter, edge detection, (see attached images) and various other functions, but the problem is I’m not able to get the edges to meet up and complete the cell pattern to where I can discern each cell as a separate object using, say, the regionprops function. I was hoping to get some guidance as to whether there are specific functions or established pre-processing steps I need in order to get the image in this format. Thanks in advance for any help!I’m trying to determine the width, height, area, and centroid of an scaly pattern shown in the attached image. I’ve tried using a gradient filter, edge detection, (see attached images) and various other functions, but the problem is I’m not able to get the edges to meet up and complete the cell pattern to where I can discern each cell as a separate object using, say, the regionprops function. I was hoping to get some guidance as to whether there are specific functions or established pre-processing steps I need in order to get the image in this format. Thanks in advance for any help! I’m trying to determine the width, height, area, and centroid of an scaly pattern shown in the attached image. I’ve tried using a gradient filter, edge detection, (see attached images) and various other functions, but the problem is I’m not able to get the edges to meet up and complete the cell pattern to where I can discern each cell as a separate object using, say, the regionprops function. I was hoping to get some guidance as to whether there are specific functions or established pre-processing steps I need in order to get the image in this format. Thanks in advance for any help! image processing, regionprops, edge detection, image segmentation MATLAB Answers — New Questions
How to create tiledlayout grid in vertical order
Hello,
How to create tiledlayout grid in vertical order?
Let’s say I want to create a tiledlayout(3,2), matlab default order is
1 2
3 4
5 6
But I want the lay out to be:
1 4
2 5
3 6
How do I do that?
Thanks,
PingHello,
How to create tiledlayout grid in vertical order?
Let’s say I want to create a tiledlayout(3,2), matlab default order is
1 2
3 4
5 6
But I want the lay out to be:
1 4
2 5
3 6
How do I do that?
Thanks,
Ping Hello,
How to create tiledlayout grid in vertical order?
Let’s say I want to create a tiledlayout(3,2), matlab default order is
1 2
3 4
5 6
But I want the lay out to be:
1 4
2 5
3 6
How do I do that?
Thanks,
Ping tiledlayout, order MATLAB Answers — New Questions
Est-ce que possible de transformer image niveau de gris en image RGB? Si oui pouvez-vous me donner un code qui fait cette transformation.
Est-ce que possible de transformer image niveau de gris en image RGB? Si oui pouvez-vous me donner un code qui fait cette transformation.Est-ce que possible de transformer image niveau de gris en image RGB? Si oui pouvez-vous me donner un code qui fait cette transformation. Est-ce que possible de transformer image niveau de gris en image RGB? Si oui pouvez-vous me donner un code qui fait cette transformation. transformer image niveau de gris en image rgb? MATLAB Answers — New Questions
Problem with integration: there is a pole on a contour
I have a problem with calculation of the complex integral
The integrand has a pole in z=1 and z=-1 lying on the unit circle.
My code are as following:
t = @(theta) exp(1i*theta);
f = @(t) (t^2+3*t+2*1i)/(t+4)/(t-1)/(t+1);
integrand = @(theta) f(t(theta))*1i*exp(1i*theta);
integral_result = integral(integrand, 0, 2*pi, ‘ArrayValued’, true, ‘AbsTol’, 1e-12, ‘RelTol’, 1e-12);
result = (1/(2*pi*1i)) * integral_result;
I_num=result;
disp([‘numerical solution=’,num2str(I_num)])
How do i fix it…I have a problem with calculation of the complex integral
The integrand has a pole in z=1 and z=-1 lying on the unit circle.
My code are as following:
t = @(theta) exp(1i*theta);
f = @(t) (t^2+3*t+2*1i)/(t+4)/(t-1)/(t+1);
integrand = @(theta) f(t(theta))*1i*exp(1i*theta);
integral_result = integral(integrand, 0, 2*pi, ‘ArrayValued’, true, ‘AbsTol’, 1e-12, ‘RelTol’, 1e-12);
result = (1/(2*pi*1i)) * integral_result;
I_num=result;
disp([‘numerical solution=’,num2str(I_num)])
How do i fix it… I have a problem with calculation of the complex integral
The integrand has a pole in z=1 and z=-1 lying on the unit circle.
My code are as following:
t = @(theta) exp(1i*theta);
f = @(t) (t^2+3*t+2*1i)/(t+4)/(t-1)/(t+1);
integrand = @(theta) f(t(theta))*1i*exp(1i*theta);
integral_result = integral(integrand, 0, 2*pi, ‘ArrayValued’, true, ‘AbsTol’, 1e-12, ‘RelTol’, 1e-12);
result = (1/(2*pi*1i)) * integral_result;
I_num=result;
disp([‘numerical solution=’,num2str(I_num)])
How do i fix it… numerical integration, cauthy, matlab code MATLAB Answers — New Questions
Get expected DataType for Inherit:auto port
Hi,
I am trying to find out if there is a way programatically to check which is the expected data type of a port which is normally defined as Inherit:auto. The only parameter which lists the data type I know of is "OutDataTypeStr" which in such cases only says "Inherit:auto". Is there a programatic way to apply the inheritance rules and check what is the expected type for this port?Hi,
I am trying to find out if there is a way programatically to check which is the expected data type of a port which is normally defined as Inherit:auto. The only parameter which lists the data type I know of is "OutDataTypeStr" which in such cases only says "Inherit:auto". Is there a programatic way to apply the inheritance rules and check what is the expected type for this port? Hi,
I am trying to find out if there is a way programatically to check which is the expected data type of a port which is normally defined as Inherit:auto. The only parameter which lists the data type I know of is "OutDataTypeStr" which in such cases only says "Inherit:auto". Is there a programatic way to apply the inheritance rules and check what is the expected type for this port? simulink, programming MATLAB Answers — New Questions
Header files not generated
#include "rtw_continuous.h"
#include "rtw_solver.h"
these header files are not generated in MATLAB.
Is there any options to know that.#include "rtw_continuous.h"
#include "rtw_solver.h"
these header files are not generated in MATLAB.
Is there any options to know that. #include "rtw_continuous.h"
#include "rtw_solver.h"
these header files are not generated in MATLAB.
Is there any options to know that. embedded coder MATLAB Answers — New Questions
How to make an image grid for matlab
I am having some difficulty with MATLAB and would appreciate your help. I have a series of values, each of which generates a slice of a large grid that I want to create. I can use MATLAB to visualize each slice individually, but I am unable to generate the grid with all the slices. Could someone help me with this? The data I have from the images, the first line is 1,1,1,1 and goes up to 2,108,160,16
This is my objective his is one of the slices I can generate
I want help with a matlab code capable of joining all the slices into a single grid, as shown in the "objective" image.I am having some difficulty with MATLAB and would appreciate your help. I have a series of values, each of which generates a slice of a large grid that I want to create. I can use MATLAB to visualize each slice individually, but I am unable to generate the grid with all the slices. Could someone help me with this? The data I have from the images, the first line is 1,1,1,1 and goes up to 2,108,160,16
This is my objective his is one of the slices I can generate
I want help with a matlab code capable of joining all the slices into a single grid, as shown in the "objective" image. I am having some difficulty with MATLAB and would appreciate your help. I have a series of values, each of which generates a slice of a large grid that I want to create. I can use MATLAB to visualize each slice individually, but I am unable to generate the grid with all the slices. Could someone help me with this? The data I have from the images, the first line is 1,1,1,1 and goes up to 2,108,160,16
This is my objective his is one of the slices I can generate
I want help with a matlab code capable of joining all the slices into a single grid, as shown in the "objective" image. construct image MATLAB Answers — New Questions
Simulink crashes when running MEX functions created with Visual Studio 2022 17.10.4
We have been running MATLAB R2023B Update 7 with Simulink models using S-Functions built with VS 2022 17.9.0. When we updated to VS 2022 17.10.4 we starting having MATLAB crashes as soon as Simulink starts executing models with these MEX functions. Is this a known issue, and do we know if moving to Update 8 or 9 will fix it?We have been running MATLAB R2023B Update 7 with Simulink models using S-Functions built with VS 2022 17.9.0. When we updated to VS 2022 17.10.4 we starting having MATLAB crashes as soon as Simulink starts executing models with these MEX functions. Is this a known issue, and do we know if moving to Update 8 or 9 will fix it? We have been running MATLAB R2023B Update 7 with Simulink models using S-Functions built with VS 2022 17.9.0. When we updated to VS 2022 17.10.4 we starting having MATLAB crashes as soon as Simulink starts executing models with these MEX functions. Is this a known issue, and do we know if moving to Update 8 or 9 will fix it? mex, simulink MATLAB Answers — New Questions
“timeout” setting not work in webread function
Hi:
I use parallel loop to grab data using "webread" , I set up the timeout option to be 10 seconds,
options = weboptions;
options.Timeout = 10;
then use command like below:
timeCost=[];
parfor i=1:1:1e4
tic
webReadTmp=webread(command,options);
timeCost(i)=toc;
end
I use "timeCost" variable to record the time needed for each webread operation. however I notice there are some webread cost more than 30 second, which means the "timeout" setting is not working here.
is there any mistake with my command?
Thanks!
YuHi:
I use parallel loop to grab data using "webread" , I set up the timeout option to be 10 seconds,
options = weboptions;
options.Timeout = 10;
then use command like below:
timeCost=[];
parfor i=1:1:1e4
tic
webReadTmp=webread(command,options);
timeCost(i)=toc;
end
I use "timeCost" variable to record the time needed for each webread operation. however I notice there are some webread cost more than 30 second, which means the "timeout" setting is not working here.
is there any mistake with my command?
Thanks!
Yu Hi:
I use parallel loop to grab data using "webread" , I set up the timeout option to be 10 seconds,
options = weboptions;
options.Timeout = 10;
then use command like below:
timeCost=[];
parfor i=1:1:1e4
tic
webReadTmp=webread(command,options);
timeCost(i)=toc;
end
I use "timeCost" variable to record the time needed for each webread operation. however I notice there are some webread cost more than 30 second, which means the "timeout" setting is not working here.
is there any mistake with my command?
Thanks!
Yu "timeout" setting not work in webread function MATLAB Answers — New Questions