Answered

How to create a rectangular mask based on current code for making an elliptical mask

I don't understand how your current code works, but you might consider modifying the code below, as appropriate: M=256; N=256...

How to create a rectangular mask based on current code for making an elliptical mask

I don't understand how your current code works, but you might consider modifying the code below, as appropriate: M=256; N=256...

5 days ago | 0

| accepted

Answered

Backslash does not provided the solution with the smallest 2-norm

In this case, we expect that MATLAB returns the solution x which has the smallest 2-norm, right? No, the backslash operator wil...

Backslash does not provided the solution with the smallest 2-norm

In this case, we expect that MATLAB returns the solution x which has the smallest 2-norm, right? No, the backslash operator wil...

5 days ago | 2

Answered

How to resample vectors of different length into the same length?

How can I achieve that? You can use interp1 Also should I resample to the biggest size out of the vectors or bring them all to...

How to resample vectors of different length into the same length?

How can I achieve that? You can use interp1 Also should I resample to the biggest size out of the vectors or bring them all to...

5 days ago | 0

Answered

How find the row number for different elements in a column?

As an example, suppose you wanted to find the first occurrence of a 2 in each column. Then one way would be, A=randi(10,10,5) ...

How find the row number for different elements in a column?

As an example, suppose you wanted to find the first occurrence of a 2 in each column. Then one way would be, A=randi(10,10,5) ...

5 days ago | 0

Answered

Help with DFT Algorithm (No FFT)

When I carry out this calculation I get the following: . No, because 1/3 of your xx are padded zeros. This will reduce your amp...

Help with DFT Algorithm (No FFT)

When I carry out this calculation I get the following: . No, because 1/3 of your xx are padded zeros. This will reduce your amp...

6 days ago | 2

| accepted

Question

Using find() is faster than direct logical indexing?

Does it make sense that using find() instead of direct logical indexing is faster in this example: A=randi(100,5e3,5e3); tim...

6 days ago | 1 answer | 0

Answered

How to call the row number of an element?

With find, but be mindful that direct logical indexing is often faster if you are seeking to modify the matrix. Compare: %Repla...

How to call the row number of an element?

With find, but be mindful that direct logical indexing is often faster if you are seeking to modify the matrix. Compare: %Repla...

6 days ago | 0

Answered

AUC or trapz for irregular shape that intersects itself

Perhaps as follows? p=polyshape(WL_1546La, WL_1546Fa); Areas=area(regions(p))

AUC or trapz for irregular shape that intersects itself

Perhaps as follows? p=polyshape(WL_1546La, WL_1546Fa); Areas=area(regions(p))

7 days ago | 0

Answered

Is it possible to loop through and set image pixels with a parfor loop?

If you have the Image Processing Toolbox, you should use imwarp to perform an image transformation.

Is it possible to loop through and set image pixels with a parfor loop?

If you have the Image Processing Toolbox, you should use imwarp to perform an image transformation.

7 days ago | 1

Answered

Why does filtering data before PCA improve results?

PCA applied to the transformed cluster should find PC1 close to L', and therefore the projections of the images on L' should be ...

Why does filtering data before PCA improve results?

PCA applied to the transformed cluster should find PC1 close to L', and therefore the projections of the images on L' should be ...

7 days ago | 0

Answered

how can I find the max value out of iterative for loop ?

Seems to be working: count=1; while 1 for i=1:20 x(i)= randi(87);% calculations end maxvalue(cou...

how can I find the max value out of iterative for loop ?

Seems to be working: count=1; while 1 for i=1:20 x(i)= randi(87);% calculations end maxvalue(cou...

8 days ago | 0

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Answered

Store m iterations of a variable in for loop

Perhaps as follows: ivals=1:step:m; J=numel(ivals); [LAT_3,LON_3,ALT_3]=deal(nan(1,J)); for j = 1:J i=ivals...

Store m iterations of a variable in for loop

Perhaps as follows: ivals=1:step:m; J=numel(ivals); [LAT_3,LON_3,ALT_3]=deal(nan(1,J)); for j = 1:J i=ivals...

8 days ago | 0

| accepted

Answered

How to generate a smooth derivative after fitting a curve to the data?

You can try some different choices of the smoothing parameter, load Data % using cubic spline pp = spline(x,y); derX= fnde...

How to generate a smooth derivative after fitting a curve to the data?

You can try some different choices of the smoothing parameter, load Data % using cubic spline pp = spline(x,y); derX= fnde...

8 days ago | 0

Answered

Using structures with Functions

@Stephen23's answer might be what you are looking for, but if you need the struct in scalar form for some reason, then the attac...

Using structures with Functions

@Stephen23's answer might be what you are looking for, but if you need the struct in scalar form for some reason, then the attac...

8 days ago | 1

Answered

How do I combine 3 figures into a single plot and compare them?

Perhaps this is what you mean. Start with 3 plots, colors={'r','g','m'} for i=1:3 figure(i); h(i)=plot((0:4)+i,colors{i}); y...

How do I combine 3 figures into a single plot and compare them?

Perhaps this is what you mean. Start with 3 plots, colors={'r','g','m'} for i=1:3 figure(i); h(i)=plot((0:4)+i,colors{i}); y...

8 days ago | 0

Answered

How to remove thin lines from the following image?

Perhaps bwpropfilt(bW,'Eccentricity',____)

How to remove thin lines from the following image?

Perhaps bwpropfilt(bW,'Eccentricity',____)

8 days ago | 0

Answered

Using bwpropfilt after imrotate

The reason, I suspect, that the number of objects seems to decrease when you imrotate is that you have several objects that are ...

Using bwpropfilt after imrotate

The reason, I suspect, that the number of objects seems to decrease when you imrotate is that you have several objects that are ...

9 days ago | 0

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Answered

how can I solve this problem

Are N and W known variables? Your code does not provide them, but if they are known, you can reorganize as a polynomial and use ...

how can I solve this problem

Are N and W known variables? Your code does not provide them, but if they are known, you can reorganize as a polynomial and use ...

9 days ago | 1

Answered

How to generate and store in different sizes vectors or cells in a loop?

Use cell arrays. interval=cell(1,length(Vneg)); for con=1:length(Vneg); interval{con}=A(A(:,1)>=Fneg(con2) & A(:,1...

How to generate and store in different sizes vectors or cells in a loop?

Use cell arrays. interval=cell(1,length(Vneg)); for con=1:length(Vneg); interval{con}=A(A(:,1)>=Fneg(con2) & A(:,1...

9 days ago | 0

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Answered

Using Curve Fitter, computing Local Maximum (y) and corresponding (x) and export x y of fitted curve to external format (Excel)

If all you're after is the local max, I would skip the curve fitting app and use polyfit. keep=~(isnan(x)|isnan(y)); x=x(keep)...

Using Curve Fitter, computing Local Maximum (y) and corresponding (x) and export x y of fitted curve to external format (Excel)

If all you're after is the local max, I would skip the curve fitting app and use polyfit. keep=~(isnan(x)|isnan(y)); x=x(keep)...

9 days ago | 0

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Answered

Exponential curve fitting with nonlinearleastsquares methood

Use fminspleas from the File Exchange, which only requires an initial guess of T1. https://www.mathworks.com/matlabcentral/file...

Exponential curve fitting with nonlinearleastsquares methood

Use fminspleas from the File Exchange, which only requires an initial guess of T1. https://www.mathworks.com/matlabcentral/file...

9 days ago | 0

Answered

How can I delete a row based on the value of the previous row?

It'll have to be done with a loop, A=[10, 11.5, 13.3 13.5 13.7 17]; i=2; while i<=numel(A) if A(i)<A(i-1)+2 ...

How can I delete a row based on the value of the previous row?

It'll have to be done with a loop, A=[10, 11.5, 13.3 13.5 13.7 17]; i=2; while i<=numel(A) if A(i)<A(i-1)+2 ...

10 days ago | 0

Answered

How can I delete a row based on the value of the previous row?

rowstodelete = diff([inf;A])<2;

How can I delete a row based on the value of the previous row?

rowstodelete = diff([inf;A])<2;

10 days ago | 0

Answered

how to convert 4D into 3D?

If you mean you want the i-th 3D frame of the 4D data, then, frame_i=cropVol(:,:,i)

how to convert 4D into 3D?

If you mean you want the i-th 3D frame of the 4D data, then, frame_i=cropVol(:,:,i)

10 days ago | 0

Answered

Retrieve cartesian coordinates from a 3D shape surface

Call ellipsoid with outputs, [X,Y,Z] = ellipsoid(xc,yc,zc,xr,yr,zr)

Retrieve cartesian coordinates from a 3D shape surface

Call ellipsoid with outputs, [X,Y,Z] = ellipsoid(xc,yc,zc,xr,yr,zr)

10 days ago | 1

| accepted

Answered

Calculating the value, excluding nan

subset=1993<=y & y<=2021; datasub=data_crsp(subset,7); ysub=y(subset)-1992; stockreturn=splitapply(@(z)mean(z,'omitnan'),...

Calculating the value, excluding nan

subset=1993<=y & y<=2021; datasub=data_crsp(subset,7); ysub=y(subset)-1992; stockreturn=splitapply(@(z)mean(z,'omitnan'),...

10 days ago | 0

Answered

How do I set coefficient variables in Fittype that was generated in Fitting toolbox?

Instead of a fitType object, use an anonymous function like in this example, https://www.mathworks.com/help/curvefit/fit.html#b...

How do I set coefficient variables in Fittype that was generated in Fitting toolbox?

Instead of a fitType object, use an anonymous function like in this example, https://www.mathworks.com/help/curvefit/fit.html#b...

11 days ago | 0

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Answered

How to detect corners of irregular binary shape?

You might try pgonCorners from the File Exchange: https://www.mathworks.com/matlabcentral/fileexchange/74181-find-vertices-in-i...

How to detect corners of irregular binary shape?

You might try pgonCorners from the File Exchange: https://www.mathworks.com/matlabcentral/fileexchange/74181-find-vertices-in-i...

11 days ago | 0

| accepted