Horizontal First Differencer on a Matrix
Have a look on the help and documentation to diff. For this case use: y = diff(x,[],2); % or explicitly 1st difference: y = d...

alrededor de 2 meses ago | 0

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How to remove space between subplots of heatmaps?
If you use the axes-handle output from subplot you can then set any of their properties as you desire: sph = subplot(3,1,1); %...

alrededor de 2 meses ago | 0

If a structure exists in a file
You can explicitly check for the existense of a variable in a .mat-file: qwe = whos('-file','your-filename.mat','cDA_External_S...

alrededor de 2 meses ago | 0

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help debugging 3-D plot code
You have to get your equations for x, y and z right: x = a*cos(phi).*sin(theta); y = b*sin(phi).*sin(theta); z = b*cos(theta)...

alrededor de 2 meses ago | 1

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Combined mean monthly values from 24 years of monthly data
Something like this perhaps: BV = table2array(baseline_values); clf subplot(2,1,1) imagesc(reshape(BV(:,4),12,[])') % Illust...

alrededor de 2 meses ago | 0

Plotting negative values on an histogram
It seems likely that you've mixed up BinCounts and BinEdges - it doesn't make much sense to have a negative number of something ...

alrededor de 2 meses ago | 0

M-point averaging filter to an image
Read the help and documentation for conv2. HTH

alrededor de 2 meses ago | 0

Why doesn't the ode15s solver work when I switch 'k1q','k2q','k12q' from a single value into vectors(more values)?
When k1q is an array you will get an error when you try to assign the product of that array with the scalar C(1) to dCdt(1) whic...

alrededor de 2 meses ago | 1

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i am getting error in line 18 of invalid use of operator.please help me solving this
OK, so you want to solve 3 coupled equations of motion for some harmonically varying solution. First you have to understand the ...

alrededor de 2 meses ago | 0

make a better map
You should try: shading flat instead of the interp option. You will have to accept the fact that you only have data in a 32-by...

2 meses ago | 0

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Solving differential equations to get accurate plot as shown.
Since you get an oscillatory behaviour of (primarily) Cecm and Crec it is very likely that you have a bug for some of the reacti...

2 meses ago | 0

How to use chebop function?
Have you installed the chebfun package? Have you added the chebfun install directory to the matlab-path? If you have it install...

2 meses ago | 0

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Improving speed of readtable
It is a rather large data-file to read. You might reduce the read-time if you use load instead of readtable - that should reduce...

2 meses ago | 0

How to create and plot an oloid in MATLAB
Have a look at the help and documentation of the convhull function. That should give you a solution for this task - in the sense...

2 meses ago | 0

Multidimensional integration in matlab
Have a look at the help and documentation for integral2. That should be the function to do 2-D integrals, that sounds like the f...

2 meses ago | 1

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Why does version R2020b gives errors when running functions such as fmincon, when version R2019a runs properly.
Have you installed the optimization toolbox in your 2020b install? If not that is where that function resides. Check the existe...

2 meses ago | 0

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Simulation of Shepp Logan phaton dataset
The phantom-function is a standard .m-function available in source-code, so you can read it clean and plain. It is simply a func...

2 meses ago | 2

Different line types for multiple curves
Maybe you'll have to accept looping a little: lstl = {'-','--'}; for i1 = 1:4, set(p(i1),'linestyle',lstl{rem(i1,2)+1}) en...

2 meses ago | 0

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Inputs must be floats, namely single or double.
When you integrate an ODE numerically there is no need whatsoever to introduce a declaration of T as a symbolic variable (the wa...

2 meses ago | 1

error occurring while solving odes using ode15s
Check your mass-matrix E and make sure it looks exactly like you expect. The 3 off-diagonal 1s looks peculiar to me. Then you ha...

2 meses ago | 0

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Find Peaks error - Expected X to be strictly increasing
Check that your X-variable is actually monotonically increasing (you might have replicate points, which then messes everything u...

2 meses ago | 0

The legend does not show the right marker:
When using legend it is always preferable to use an array of handles returned from the plotting functions. Try something like: ...

2 meses ago | 0

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stft for complex data
Shouldn't that be as simle as: Acmplx = I + 1i*Q; spec = fft(Acmplx); % or spectrogram etc HTH

2 meses ago | 0

How do I interpolate in 5d?
Have a look at the help and documentation for interpn. HTH

2 meses ago | 0

Sparse matrix from the columns of an initial matrix
Something like this might work: vals = []; idx1 = []; idx2 = []; for j = 1:n idx1 = [idx1,1:n]; c...

2 meses ago | 0

Is there a way to adaptively sample 2-D surfaces ?
It is not entirely clear what your "problem situation" or "design desires" are. These might be very important for what type of s...

2 meses ago | 0

Error using odearguments (line 21) When the first argument to ode23s is a function handle, the tspan argument must have at least two elements.
Your t variable will only have one component as you define it. My guess is that you want 100 elements between 0 and 1. If that's...

3 meses ago | 0

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F(N) versus N plot for logistic differential equation
To solve for N you simply have to implement the ODE as a matlab-function, either as in an m-file or as an anonymous function-han...

3 meses ago | 0