Post Content Post Content i need help… MATLAB Answers — New Questions

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Hello everyone,
I designed a Bandpass Filter using the filterDesigner app. It is an 18th order IIR filter.
Then I export the filter both as df2sos object and "SOS and G" matrices.
Afterwards, I try filtering my data with:
y = filtfilt(Hd,x);
It gives the error: Not enough input arguments.
Well. Why don’t I use:
y = filtfilt(Hd.sosMatrix,Hd.scaleValues,x);
% or
y = filtfilt(SOS,G,x);
These do not work for my filter; they result in unstable filters. Even though my originally designed filter is stable, they give unstable results. Here is the MATLAB page for this issue.
So, how to use FiltFilt function with my df2sos object or my "SOS and G" matrices, without getting an unstable result? I’d really appreaciate some help.
Regards,
Berk

Additional Details:
Here is the code to generate my filter object:
Fstop1 = 0.0001; % First Stopband Frequency
Fpass1 = 0.0004; % First Passband Frequency
Fpass2 = 0.08; % Second Passband Frequency
Fstop2 = 0.12; % Second Stopband Frequency
Astop1 = 50; % First Stopband Attenuation (dB)
Apass = 0.5; % Passband Ripple (dB)
Astop2 = 50; % Second Stopband Attenuation (dB)

h = fdesign.bandpass(‘fst1,fp1,fp2,fst2,ast1,ap,ast2’, Fstop1, Fpass1, …
Fpass2, Fstop2, Astop1, Apass, Astop2);

Hd = designfilt(h, ‘cheby2’, …
‘MatchExactly’, ‘stopband’, …
‘SystemObject’, true);
and the screenshot from the filterDesigner app:Hello everyone,
I designed a Bandpass Filter using the filterDesigner app. It is an 18th order IIR filter.
Then I export the filter both as df2sos object and "SOS and G" matrices.
Afterwards, I try filtering my data with:
y = filtfilt(Hd,x);
It gives the error: Not enough input arguments.
Well. Why don’t I use:
y = filtfilt(Hd.sosMatrix,Hd.scaleValues,x);
% or
y = filtfilt(SOS,G,x);
These do not work for my filter; they result in unstable filters. Even though my originally designed filter is stable, they give unstable results. Here is the MATLAB page for this issue.
So, how to use FiltFilt function with my df2sos object or my "SOS and G" matrices, without getting an unstable result? I’d really appreaciate some help.
Regards,
Berk

Additional Details:
Here is the code to generate my filter object:
Fstop1 = 0.0001; % First Stopband Frequency
Fpass1 = 0.0004; % First Passband Frequency
Fpass2 = 0.08; % Second Passband Frequency
Fstop2 = 0.12; % Second Stopband Frequency
Astop1 = 50; % First Stopband Attenuation (dB)
Apass = 0.5; % Passband Ripple (dB)
Astop2 = 50; % Second Stopband Attenuation (dB)

h = fdesign.bandpass(‘fst1,fp1,fp2,fst2,ast1,ap,ast2’, Fstop1, Fpass1, …
Fpass2, Fstop2, Astop1, Apass, Astop2);

Hd = designfilt(h, ‘cheby2’, …
‘MatchExactly’, ‘stopband’, …
‘SystemObject’, true);
and the screenshot from the filterDesigner app: Hello everyone,
I designed a Bandpass Filter using the filterDesigner app. It is an 18th order IIR filter.
Then I export the filter both as df2sos object and "SOS and G" matrices.
Afterwards, I try filtering my data with:
y = filtfilt(Hd,x);
It gives the error: Not enough input arguments.
Well. Why don’t I use:
y = filtfilt(Hd.sosMatrix,Hd.scaleValues,x);
% or
y = filtfilt(SOS,G,x);
These do not work for my filter; they result in unstable filters. Even though my originally designed filter is stable, they give unstable results. Here is the MATLAB page for this issue.
So, how to use FiltFilt function with my df2sos object or my "SOS and G" matrices, without getting an unstable result? I’d really appreaciate some help.
Regards,
Berk

Additional Details:
Here is the code to generate my filter object:
Fstop1 = 0.0001; % First Stopband Frequency
Fpass1 = 0.0004; % First Passband Frequency
Fpass2 = 0.08; % Second Passband Frequency
Fstop2 = 0.12; % Second Stopband Frequency
Astop1 = 50; % First Stopband Attenuation (dB)
Apass = 0.5; % Passband Ripple (dB)
Astop2 = 50; % Second Stopband Attenuation (dB)

h = fdesign.bandpass(‘fst1,fp1,fp2,fst2,ast1,ap,ast2’, Fstop1, Fpass1, …
Fpass2, Fstop2, Astop1, Apass, Astop2);

Hd = designfilt(h, ‘cheby2’, …
‘MatchExactly’, ‘stopband’, …
‘SystemObject’, true);
and the screenshot from the filterDesigner app: filterdesigner, signalprocessingtoolbox, filtfilt, filter, unstable, df2sos, iir filter, sos g MATLAB Answers — New Questions

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Hi everyone,
I am working on a robot model in SolidWorks 2021 and have exported it to MATLAB 2023b for simulation in Simscape. However, I encountered an issue where the coordinate system of my robot seems to be flipped or mismatched compared to the one I set up in SolidWorks. Specifically, the Z-axis appears to be inverted in MATLAB.
Here are some details about my setup:
I used the Simscape Multibody Link plugin to export the SolidWorks model.
The transform settings in MATLAB use an arbitrary axis rotation and Cartesian translation, as exported.
I have verified the axis and angle values, but the coordinate system doesn’t match the original SolidWorks model.
My questions are:
How can I ensure that the coordinate systems in MATLAB/Simscape exactly match those in SolidWorks?
Are there specific settings during the export or import process that I need to check to avoid this mismatch?
If the coordinate system is flipped, what adjustments should I make in MATLAB to correct it without breaking the simulation?
Any guidance or tips would be greatly appreciated! Thank you in advance.Hi everyone,
I am working on a robot model in SolidWorks 2021 and have exported it to MATLAB 2023b for simulation in Simscape. However, I encountered an issue where the coordinate system of my robot seems to be flipped or mismatched compared to the one I set up in SolidWorks. Specifically, the Z-axis appears to be inverted in MATLAB.
Here are some details about my setup:
I used the Simscape Multibody Link plugin to export the SolidWorks model.
The transform settings in MATLAB use an arbitrary axis rotation and Cartesian translation, as exported.
I have verified the axis and angle values, but the coordinate system doesn’t match the original SolidWorks model.
My questions are:
How can I ensure that the coordinate systems in MATLAB/Simscape exactly match those in SolidWorks?
Are there specific settings during the export or import process that I need to check to avoid this mismatch?
If the coordinate system is flipped, what adjustments should I make in MATLAB to correct it without breaking the simulation?
Any guidance or tips would be greatly appreciated! Thank you in advance. Hi everyone,
I am working on a robot model in SolidWorks 2021 and have exported it to MATLAB 2023b for simulation in Simscape. However, I encountered an issue where the coordinate system of my robot seems to be flipped or mismatched compared to the one I set up in SolidWorks. Specifically, the Z-axis appears to be inverted in MATLAB.
Here are some details about my setup:
I used the Simscape Multibody Link plugin to export the SolidWorks model.
The transform settings in MATLAB use an arbitrary axis rotation and Cartesian translation, as exported.
I have verified the axis and angle values, but the coordinate system doesn’t match the original SolidWorks model.
My questions are:
How can I ensure that the coordinate systems in MATLAB/Simscape exactly match those in SolidWorks?
Are there specific settings during the export or import process that I need to check to avoid this mismatch?
If the coordinate system is flipped, what adjustments should I make in MATLAB to correct it without breaking the simulation?
Any guidance or tips would be greatly appreciated! Thank you in advance. simscape, solidworks, multibody, coordinate-system, model MATLAB Answers — New Questions

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The spring is to exert some force on the fluid inside the cyinder, thus pressurizing it. I want to find out the response rate (outlet flowrate) of the fluid when pushed out by the spring with different stiffness rates? Can anyone help? How to model this block in SimHydraulics?The spring is to exert some force on the fluid inside the cyinder, thus pressurizing it. I want to find out the response rate (outlet flowrate) of the fluid when pushed out by the spring with different stiffness rates? Can anyone help? How to model this block in SimHydraulics? The spring is to exert some force on the fluid inside the cyinder, thus pressurizing it. I want to find out the response rate (outlet flowrate) of the fluid when pushed out by the spring with different stiffness rates? Can anyone help? How to model this block in SimHydraulics? simhydraulics, simulink, matlab MATLAB Answers — New Questions

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I’m not sure how to add vectors that visualize the effect of data set parameters to an NMDS plot.
Using the example provided by matlab for function mdscale (shown below), I can create the figure with points for each observation (i.e. cerials of a certain brand). How would I go about adding vectors to the plot for each of the parameters included in the analysis, where the length of the vector indicates the strength of effect on the ordination. For the cerial example, these vectors would represent calories, protien, fat, sodium, fiber, carbo, sugars, shelf, potass, and vitamins. If you could show my how to do this in the sample below, that would be really helpful!

load cereal.mat
X = [Calories Protein Fat Sodium Fiber …
Carbo Sugars Shelf Potass Vitamins];
% Take a subset from a single manufacturer
mfg1 = strcmp(‘G’,cellstr(Mfg));
X = X(mfg1,:);
dissimilarities = pdist(zscore(X),’cityblock’);
[Y,stress] =…
mdscale(dissimilarities,2,’criterion’,’stress’);
plot(Y(:,1),Y(:,2),’o’,’LineWidth’,2);
gname(Name(mfg1))I’m not sure how to add vectors that visualize the effect of data set parameters to an NMDS plot.
Using the example provided by matlab for function mdscale (shown below), I can create the figure with points for each observation (i.e. cerials of a certain brand). How would I go about adding vectors to the plot for each of the parameters included in the analysis, where the length of the vector indicates the strength of effect on the ordination. For the cerial example, these vectors would represent calories, protien, fat, sodium, fiber, carbo, sugars, shelf, potass, and vitamins. If you could show my how to do this in the sample below, that would be really helpful!

load cereal.mat
X = [Calories Protein Fat Sodium Fiber …
Carbo Sugars Shelf Potass Vitamins];
% Take a subset from a single manufacturer
mfg1 = strcmp(‘G’,cellstr(Mfg));
X = X(mfg1,:);
dissimilarities = pdist(zscore(X),’cityblock’);
[Y,stress] =…
mdscale(dissimilarities,2,’criterion’,’stress’);
plot(Y(:,1),Y(:,2),’o’,’LineWidth’,2);
gname(Name(mfg1)) I’m not sure how to add vectors that visualize the effect of data set parameters to an NMDS plot.
Using the example provided by matlab for function mdscale (shown below), I can create the figure with points for each observation (i.e. cerials of a certain brand). How would I go about adding vectors to the plot for each of the parameters included in the analysis, where the length of the vector indicates the strength of effect on the ordination. For the cerial example, these vectors would represent calories, protien, fat, sodium, fiber, carbo, sugars, shelf, potass, and vitamins. If you could show my how to do this in the sample below, that would be really helpful!

load cereal.mat
X = [Calories Protein Fat Sodium Fiber …
Carbo Sugars Shelf Potass Vitamins];
% Take a subset from a single manufacturer
mfg1 = strcmp(‘G’,cellstr(Mfg));
X = X(mfg1,:);
dissimilarities = pdist(zscore(X),’cityblock’);
[Y,stress] =…
mdscale(dissimilarities,2,’criterion’,’stress’);
plot(Y(:,1),Y(:,2),’o’,’LineWidth’,2);
gname(Name(mfg1)) nmds MATLAB Answers — New Questions

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On simscape Multibody, I would like to simulate solid material (i.e. solid fertilizer) flowing from a container to another container, initially by gravity. Any ideas how can I do this? I could not find a way to model this material. Initially I tough about modeling hundreds of spheres with spatial block contacts, but not sure if this is possible or maybe another approach.On simscape Multibody, I would like to simulate solid material (i.e. solid fertilizer) flowing from a container to another container, initially by gravity. Any ideas how can I do this? I could not find a way to model this material. Initially I tough about modeling hundreds of spheres with spatial block contacts, but not sure if this is possible or maybe another approach. On simscape Multibody, I would like to simulate solid material (i.e. solid fertilizer) flowing from a container to another container, initially by gravity. Any ideas how can I do this? I could not find a way to model this material. Initially I tough about modeling hundreds of spheres with spatial block contacts, but not sure if this is possible or maybe another approach. simscape multibody MATLAB Answers — New Questions

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I have some data that is stored as a 1666×1 cell array. Each cell contains a 4×19 double. I need to extract this data and attach it to a timeseries object. Timeseries will not take a cell array directly, so I need to extract the cells.
So let’s say the cell array is named data, and the timeseries is ts. I need:
ts.Data(1) = data{1}
ts.Data(2) = data{2}
etc.
cell2mat() concatenates everything into 6664×19, and I can’t get reshape() to chop it up into the correct 4×19 blocks. I could do it in a for loop, but that’s not very satisfying in MATLAB.

I know this is a simple syntax thing, but I can’t seem to find an answer that works.I have some data that is stored as a 1666×1 cell array. Each cell contains a 4×19 double. I need to extract this data and attach it to a timeseries object. Timeseries will not take a cell array directly, so I need to extract the cells.
So let’s say the cell array is named data, and the timeseries is ts. I need:
ts.Data(1) = data{1}
ts.Data(2) = data{2}
etc.
cell2mat() concatenates everything into 6664×19, and I can’t get reshape() to chop it up into the correct 4×19 blocks. I could do it in a for loop, but that’s not very satisfying in MATLAB.

I know this is a simple syntax thing, but I can’t seem to find an answer that works. I have some data that is stored as a 1666×1 cell array. Each cell contains a 4×19 double. I need to extract this data and attach it to a timeseries object. Timeseries will not take a cell array directly, so I need to extract the cells.
So let’s say the cell array is named data, and the timeseries is ts. I need:
ts.Data(1) = data{1}
ts.Data(2) = data{2}
etc.
cell2mat() concatenates everything into 6664×19, and I can’t get reshape() to chop it up into the correct 4×19 blocks. I could do it in a for loop, but that’s not very satisfying in MATLAB.

I know this is a simple syntax thing, but I can’t seem to find an answer that works. timeseries, matrix, cell MATLAB Answers — New Questions

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Hello,
I made a previous post about a rocket simulation project I have. I am still stuck on the same project, but I managed to solve some of the problems. The current issue is some errors I get when I run problem c). My theory, after some debuging is that the issue is somwhere between row 260 and 271. Can anyone explain what these errors are from and how I can fix them?
Enter which problem ao run, a, c or d, enter problem: c
268 elseif tu<params_mini(3)
Index exceeds the number of array elements. Index must not exceed 4.

Error in testador>@(vx)(problem_main(5)*cosd(problem_param(5))-problem_main(4)*vx*V)/total_mass (line 311)
dvxdt = @(vx) (problem_main(5) * cosd(problem_param(5)) – problem_main(4) * vx * V) / total_mass;

Error in testador>Rungekutta (line 318)
k1vx = dvxdt(problem_param(3)); k1vy = dvydt(problem_param(4));

Error in testador>trajectory (line 269)
params = Rungekutta(params, user_inp, access_keys, dt_unrefined); % Runs mini rocket

Error in testador (line 32)
Height_distance = trajectory(params, user_inp, access_keys); % Pass params.c to rungekuttaHello,
I made a previous post about a rocket simulation project I have. I am still stuck on the same project, but I managed to solve some of the problems. The current issue is some errors I get when I run problem c). My theory, after some debuging is that the issue is somwhere between row 260 and 271. Can anyone explain what these errors are from and how I can fix them?
Enter which problem ao run, a, c or d, enter problem: c
268 elseif tu<params_mini(3)
Index exceeds the number of array elements. Index must not exceed 4.

Error in testador>@(vx)(problem_main(5)*cosd(problem_param(5))-problem_main(4)*vx*V)/total_mass (line 311)
dvxdt = @(vx) (problem_main(5) * cosd(problem_param(5)) – problem_main(4) * vx * V) / total_mass;

Error in testador>Rungekutta (line 318)
k1vx = dvxdt(problem_param(3)); k1vy = dvydt(problem_param(4));

Error in testador>trajectory (line 269)
params = Rungekutta(params, user_inp, access_keys, dt_unrefined); % Runs mini rocket

Error in testador (line 32)
Height_distance = trajectory(params, user_inp, access_keys); % Pass params.c to rungekutta Hello,
I made a previous post about a rocket simulation project I have. I am still stuck on the same project, but I managed to solve some of the problems. The current issue is some errors I get when I run problem c). My theory, after some debuging is that the issue is somwhere between row 260 and 271. Can anyone explain what these errors are from and how I can fix them?
Enter which problem ao run, a, c or d, enter problem: c
268 elseif tu<params_mini(3)
Index exceeds the number of array elements. Index must not exceed 4.

Error in testador>@(vx)(problem_main(5)*cosd(problem_param(5))-problem_main(4)*vx*V)/total_mass (line 311)
dvxdt = @(vx) (problem_main(5) * cosd(problem_param(5)) – problem_main(4) * vx * V) / total_mass;

Error in testador>Rungekutta (line 318)
k1vx = dvxdt(problem_param(3)); k1vy = dvydt(problem_param(4));

Error in testador>trajectory (line 269)
params = Rungekutta(params, user_inp, access_keys, dt_unrefined); % Runs mini rocket

Error in testador (line 32)
Height_distance = trajectory(params, user_inp, access_keys); % Pass params.c to rungekutta trajectory, matlab, differential equations MATLAB Answers — New Questions

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If one uses the data cursor on a pcolor plot, you will see three coordinates, X, Y, and Z, but the Z coordinate is always zero. It took me some time to realize that pcolor is simply a variant of the surface function, with the view fixed from above (normal to the xy plane). Inspection of the data associated with the pcolor handle will show that the "Z" values are actually stored in the CData array, and the ZData array is otherwise set to zero. This is a clever arrangement in that plot is fixed at Z = 0, and the Z values are otherwise rendered as scaled colors. The downside is that this arrangement cripples the datacursor (i.e. the Z value is not correctly reported).
One solution is to set ZData = CData (see Figure 2 produced by the code below). The datacursor will now show local Z values. The downside is that pcolor surface is now fully 3D. As a consequence, other plot elements (contours, points, lines) may be masked by this 3D surface. You can see the 3D "pcolor" surface in figure 2 by rotating the plot or by running the command "view(3)" in the command window.
The simpliest "fix" would be to add "C" values to the datacursor. (Perhaps I should suggest this as a new feature.) You will find that if you click on the contour lines, that the datacursor reports back with a variable "Level", so this kind of fix is possible. Or I could write a custom modifcation to the datacursor.
My hope is that someone out there may have found a simplier fix.
Best,
Mark

% Create data
[X,Y] = meshgrid(-2:0.2:2,-2:0.2:2);
Z = X.*exp(-X.^2 – Y.^2);
% Pcolor plot without modification. Datacursor will show Z = 0. Superimposed contours work okay.
figure(1)
hold on
hP = pcolor(X,Y,Z); shading interp;
contour(X,Y,Z, ‘Color’, ‘k’, ‘LineWidth’, 1);
datacursormode on
% PColor plot with modification (ZData = CData), Z value in data cursor works, but contours are locally masked.
figure(2)
hold on
hP = pcolor(X,Y,Z); shading interp;
hP.ZData = hP.CData;
contour(X,Y,Z, ‘Color’, ‘k’, ‘LineWidth’, 1);
datacursormode onIf one uses the data cursor on a pcolor plot, you will see three coordinates, X, Y, and Z, but the Z coordinate is always zero. It took me some time to realize that pcolor is simply a variant of the surface function, with the view fixed from above (normal to the xy plane). Inspection of the data associated with the pcolor handle will show that the "Z" values are actually stored in the CData array, and the ZData array is otherwise set to zero. This is a clever arrangement in that plot is fixed at Z = 0, and the Z values are otherwise rendered as scaled colors. The downside is that this arrangement cripples the datacursor (i.e. the Z value is not correctly reported).
One solution is to set ZData = CData (see Figure 2 produced by the code below). The datacursor will now show local Z values. The downside is that pcolor surface is now fully 3D. As a consequence, other plot elements (contours, points, lines) may be masked by this 3D surface. You can see the 3D "pcolor" surface in figure 2 by rotating the plot or by running the command "view(3)" in the command window.
The simpliest "fix" would be to add "C" values to the datacursor. (Perhaps I should suggest this as a new feature.) You will find that if you click on the contour lines, that the datacursor reports back with a variable "Level", so this kind of fix is possible. Or I could write a custom modifcation to the datacursor.
My hope is that someone out there may have found a simplier fix.
Best,
Mark

% Create data
[X,Y] = meshgrid(-2:0.2:2,-2:0.2:2);
Z = X.*exp(-X.^2 – Y.^2);
% Pcolor plot without modification. Datacursor will show Z = 0. Superimposed contours work okay.
figure(1)
hold on
hP = pcolor(X,Y,Z); shading interp;
contour(X,Y,Z, ‘Color’, ‘k’, ‘LineWidth’, 1);
datacursormode on
% PColor plot with modification (ZData = CData), Z value in data cursor works, but contours are locally masked.
figure(2)
hold on
hP = pcolor(X,Y,Z); shading interp;
hP.ZData = hP.CData;
contour(X,Y,Z, ‘Color’, ‘k’, ‘LineWidth’, 1);
datacursormode on If one uses the data cursor on a pcolor plot, you will see three coordinates, X, Y, and Z, but the Z coordinate is always zero. It took me some time to realize that pcolor is simply a variant of the surface function, with the view fixed from above (normal to the xy plane). Inspection of the data associated with the pcolor handle will show that the "Z" values are actually stored in the CData array, and the ZData array is otherwise set to zero. This is a clever arrangement in that plot is fixed at Z = 0, and the Z values are otherwise rendered as scaled colors. The downside is that this arrangement cripples the datacursor (i.e. the Z value is not correctly reported).
One solution is to set ZData = CData (see Figure 2 produced by the code below). The datacursor will now show local Z values. The downside is that pcolor surface is now fully 3D. As a consequence, other plot elements (contours, points, lines) may be masked by this 3D surface. You can see the 3D "pcolor" surface in figure 2 by rotating the plot or by running the command "view(3)" in the command window.
The simpliest "fix" would be to add "C" values to the datacursor. (Perhaps I should suggest this as a new feature.) You will find that if you click on the contour lines, that the datacursor reports back with a variable "Level", so this kind of fix is possible. Or I could write a custom modifcation to the datacursor.
My hope is that someone out there may have found a simplier fix.
Best,
Mark

% Create data
[X,Y] = meshgrid(-2:0.2:2,-2:0.2:2);
Z = X.*exp(-X.^2 – Y.^2);
% Pcolor plot without modification. Datacursor will show Z = 0. Superimposed contours work okay.
figure(1)
hold on
hP = pcolor(X,Y,Z); shading interp;
contour(X,Y,Z, ‘Color’, ‘k’, ‘LineWidth’, 1);
datacursormode on
% PColor plot with modification (ZData = CData), Z value in data cursor works, but contours are locally masked.
figure(2)
hold on
hP = pcolor(X,Y,Z); shading interp;
hP.ZData = hP.CData;
contour(X,Y,Z, ‘Color’, ‘k’, ‘LineWidth’, 1);
datacursormode on pcolor, datacursor, surface MATLAB Answers — New Questions

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I have to write a relatively large cell array to excel. The text is primarily column headers but the data does have some text intertwined in it. Is there a simple way to do this?

I’ve done some digging but most everything I’ve found says use _fprintf_ and specify when data is of a specific type. This data is too large to run something like that.

The text data is in specific columns, if there were a way to identify text data as strings and just tell MATLAB that all other fields are numeric, that’s viable.I have to write a relatively large cell array to excel. The text is primarily column headers but the data does have some text intertwined in it. Is there a simple way to do this?

I’ve done some digging but most everything I’ve found says use _fprintf_ and specify when data is of a specific type. This data is too large to run something like that.

The text data is in specific columns, if there were a way to identify text data as strings and just tell MATLAB that all other fields are numeric, that’s viable. I have to write a relatively large cell array to excel. The text is primarily column headers but the data does have some text intertwined in it. Is there a simple way to do this?

I’ve done some digging but most everything I’ve found says use _fprintf_ and specify when data is of a specific type. This data is too large to run something like that.

The text data is in specific columns, if there were a way to identify text data as strings and just tell MATLAB that all other fields are numeric, that’s viable. xlswrite, fprintf, csvwrite MATLAB Answers — New Questions

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