Bjorn Gustavsson

Last seen: Today

UIT, the Arctic University of Norway

911 total contributions since 2001

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Answered
Random set of vectors and sort them via the x axis
Have a look at the help and documentation of the function sortrows. Also (if this is a educational programming task) read the he...

6 hours ago | 0

Answered
How to control color and the intensity in a pcolor figure?
You could try something like this: lambda = 400:700; % Wavelengths in nm. I_of_lambda = % Solar-spectral intensity as a functi...

1 day ago | 1

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Answered
Error using ode45
Perhaps your calling has become too "traditional" and is not properly supported. In that case (and in general) it might be enoug...

1 day ago | 0

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Adding Harmonics of a sine wave together
You have to take into account that the fft returns complex Fourier-coefficient - that is both real and imaginary components. So ...

2 days ago | 0

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How to plot scatter graph with colourmap functon
To make it short and simple couldn't you just use scatter and let it automatically scale the values? scatter(x,y,23,myVal,'fill...

2 days ago | 0

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Double integral with rectangle transformation
No. Check things like this by simply doing things like this: [x,y] = meshgrid(linspace(-2,2,401)); pcolor(x,y,abs(x)+abs(y)),s...

2 days ago | 0

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ODE with time dependant variable
Go to the help and then online documentation for ODE45, there you will find illustrated examples for both multiple coupled ODEs ...

2 days ago | 0

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Equal Axis reduce the plot size
That is a terrible problen, what happens in your case, with increasingly narrow axes is (likely) unavoidable when you get very d...

2 days ago | 0

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solving a coupled differential equations using ODE45
You have to put both ODEs together and integrate the pair at once. Let's look at an example equation: That pair of equations ...

2 days ago | 1

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Answered
Let other applications use Matlab's version of the CUDA toolkit
0: I have no idea about legalities. 1, I found a lot with unix find: $ find ./ -iname \*cuda\*.so\* ./R2020a/bin/glnxa64/libo...

3 days ago | 0

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How to more efficiently populate a sparse matrix
The general advice is to calculate and save the non-zero elements, and their array-indices, in 3 arrays and then once they've be...

3 days ago | 0

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Answered
vpaintegral() returns wrong answer for g(t) = (mod(t,5))^2
Peculiar. If you look at g(t) you will see (well in my version of matlab): g(t) = (mod(t,5))^2 g(t) = t^2 Which shows that t...

4 days ago | 0

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Answered
Why is it that Matlab has so many data types?
Partial "answer": In the beginning there were the double (32-bit?) and the char, and everything was peaceful, then they ate of...

5 days ago | 0

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how to convert light spectral / intensity to RGB value?
Well I assume that you want to convert the envelope of the coloured region into a single RGB-tripplet. In your particular case I...

5 days ago | 0

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Perform FFTW of a song
Instead of using the fft, that calculates one fourier-transform of the entire time-series, have a look at the spectrogram functi...

5 days ago | 0

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Break title into multiple lines? Part 2
This works: title1 = string('The first title-row'); title2 = string('Some Rosetta stonery'); title3 = string('Den sista titel...

5 days ago | 0

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Answered
Multiplication of tranformation matrices gives strange result
You have confused permutation-matrices with mirroring and rotation-matrices. They are not the same. Your Rccw60 is not (what I t...

8 days ago | 0

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How Do I plot Lat Long Altitude into a 2D countour
The problem you have is that you have coordinates for contours one level at a time, however since you have multiple closed loops...

9 days ago | 0

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Minimize Difference in Partition Sums from Experimental Data
Yup, you will find the algorithm and information here: partition problem (wikipedia). HTH

9 days ago | 0

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Newline in text files
When I want to explicitly write \n for new-line I include it explicitly in the string-specification: fid1 = fopen('Testfile.txt...

10 days ago | 0

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Answered
How to fix/steady the position of a counter in plot title.
Perhaps you can use the same type of zero-padding often used for filenames? Something like: tstr = sprintf('%04d',loop_idx); O...

10 days ago | 0

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Reshape data vector for a surf plot over a non-rectangular domain
If you have your x, y and z data in 1-D arrays you can use trisurf see the help and documentation for that function for usage. I...

10 days ago | 1

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2d image reconstruction from 1D images
That definitely looks like the text-book definition of the Radon-iRadon transform pair setup. The limitation here is the 10 stri...

11 days ago | 0

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Error: Index in position 1 exceeds array bounds
I think you would benefit from using the fact that there is information about the number of elements in a contour-segment in C. ...

11 days ago | 0

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Interp1-Input coordinates must be real.
Then it must be because your theta_n has become complex. How that came to be is impossible to guess based on this information. I...

11 days ago | 0

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correlation of two signal
Why do you want to use circshift? That would put some of your last samples first! That's not the way to go about this. To do th...

11 days ago | 0

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Answered
ODE solving lack of span inputs
OK, you have 2 coupled ODEs. If I expand the D/Dt(log(V(t))) to 1/V(t)*D/Dt(V(t) I'd get something like this: function dVdtdcad...

12 days ago | 0

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Answered
ODE solving lack of span inputs
The error is most likely in the second ode45-call. In that subfunction the time t will always be a scalar. You might want to cha...

12 days ago | 0

Answered
Defining ODE function as function file
The way you've coded ConcA it should solve an ODE that looks like this: That might very well be the ODE you need to solve, bu...

12 days ago | 0

Answered
How to use ODE solvers for a 2nd order differential equation with a Mass Matrix ?
As far as I understand all you have to is to do the same conversion from a system of second order ODEs to a twice as big system ...

12 days ago | 1

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