Answered
How to convert an optimization variable to symbolic variable?
You can use the evaluate() command to substitute in values.

2 days ago | 0

Answered
Set elements in a 3D array to zero based on a condition
Qr=max(Qr,0);

3 days ago | 0

Answered
Set elements in a 3D array to zero based on a condition
Qr(Qr<0)=0;

3 days ago | 0

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Answered
reduction variables and evaluation order
First remember that each worker is assigned some consecutive subset of loop iterations. The worker will execute the iterations w...

3 days ago | 0

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Answered
max value of a function
In general I use: x= double(solve(diff(func))); This assumes there are no local min/max or saddle points. if i try to use max...

3 days ago | 0

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Answered
Fastest way to compute a multiplication of matrices times a sequence of kronecker products
With this FEX package https://www.mathworks.com/matlabcentral/fileexchange/25969-efficient-object-oriented-kronecker-product-ma...

3 days ago | 0

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Answered
for loop storing the same variable
Because in every pass through the loop, you assign the result to the same location. Perhaps you meant, demodulated_power_vector...

3 days ago | 0

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Answered
Error when using sptensor in parfor
You could try with ndSparse() instead of sptensor() https://www.mathworks.com/matlabcentral/fileexchange/29832-n-dimensional-sp...

6 days ago | 0

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Answered
Calculate the mean of nonzero pixels and setting a threshold
fun=@(z) nanmean(z(z<99)); my_mean = accumarray(double(mask(:))+1, my_array(:),[], fun)

6 days ago | 1

Answered
Can I use a nearest neighbor extrapolation strategy with interp1?
If you want to mix interpolation and extrapolation methods, use griddedInterpolant instead: F=griddedInterpolant(1:5,'linear','...

7 days ago | 0

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Answered
Find unique number sets
A = [1 4; 2 3; 3 2; 1 4]; [B,iA]=unique(sort(A,2),'rows')

7 days ago | 0

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Answered
How to find all possible 8x8 submatrices of a 13x8 matrix?
Using this File Exchange tool set, https://www.mathworks.com/matlabcentral/fileexchange/115340-block-transposition-permutation-...

7 days ago | 1

Answered
Plotting graph for specific columns and rows
plot(yourTable{1:4000,20}, yourTable{1:4000,60})

7 days ago | 0

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Answered
Class implementation such that assignment x=MyObj does in fact x=MyObj.prop1
You can't have precisely what you have asked for, but you can do this, classdef TestClass < handle properties pro...

7 days ago | 0

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Answered
How to create a rectangular mask based on current code for making an elliptical mask
You could also just use poly2mask. This would avoid the overhead of imrotate. M=256; N=256; %Image dimensions diamMax=60; ...

7 days ago | 0

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...

7 days ago | 0

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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...

7 days ago | 2

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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...

7 days ago | 0

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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) ...

7 days ago | 0

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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...

8 days ago | 2

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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...

8 days ago | 1 answer | 0

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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...

8 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))

9 days ago | 0

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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.

9 days ago | 1

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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 ...

9 days ago | 0

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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...

10 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...

10 days ago | 0

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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...

10 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...

10 days ago | 1

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