Community Profile # Bjorn Gustavsson

### UIT, the Arctic University of Norway

Last seen: 3 days ago Active since 2001

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operating Matlab via Ubuntu terminal
It should be possible to do things like this from any standard unix-terminal: \$ matlab -nodesktop -nosplash -r YOUR-SCRIPT You...

4 days ago | 0

Value dash outside a 2D plot
You can do this: set(gca,'TickDir','out') HTH

8 days ago | 0

Creating a graph with error bars
You can use the errorbar function for plots like this. Check the help and documentation for that function. If that function does...

8 days ago | 0

How to extract values within a circular region from a griddata?
You "simply" only ask for the values inside that circular region. You can do it at least two different ways: N = 100; xv = lin...

10 days ago | 0

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2 equations, 2 unknowns - fminsearch(), fminunc() applied on numerical data
From your description you have 800-by-1300 linear equations of the type: a + x = b + y and you want to solve for both x and y....

12 days ago | 0

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Local variance estimation for image filtering
You get that result because medfilt2 will select the median value of the pixel-intensities of your region, and completely discar...

13 days ago | 0

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How to read the coordinated from the plot in MATLAB 2018 version?
If you make a simple graph: ph = plot(X,Y); Then you can always extract the data-points from the plot-handle ph: xGraph = get...

13 days ago | 0

How to calculate the L2 (Euclidean) and L1 (cityblock, or we say Manhattan distance) distance based on longitude and latitude?
It seems to me that there is no obvious good definition of a Manhattan-distance on a spherical surface (even less so on a geoid)...

14 days ago | 0

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Colorbars belonging to more than one subplot/axis
perhaps something like this: figure(1) cx_12 = [min(min(var1(:)),min(var2(:))),max(max(var1(:)),max(var2(:)))]; cx_34 = [min(...

14 days ago | 0

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Processing large matrix faster
This ought to be done in one go: coods = M(:,M(:,3)<-80); In the case you cannot do it in a vectorized way and cannot determ...

14 days ago | 0

From char to double for plotting
First you should store the data-sets in some kind of array. For the most tolerant storage (that doesn't care about different dim...

15 days ago | 1

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Find 2D intersection in lat lon between curve (rivers) and satellite traces (2D polygon) on a map
If you have a single-pass of the satellite you could check what "river-points" are inside the ground-track with the inpolygon fu...

17 days ago | 0

Is there a way in MATLAB to guess the values of a matrix just like in the EES software?
You can easily initialize your variable to a fixed-valued array: a = 17; t = 16.05*ones([1,round(a)]); If you want a function...

20 days ago | 0

Mass of a wire in shape of helix
The symbolic tools make the default interpretation that all variables are complex. Therefore it cannot make that simplification....

20 days ago | 0

Diagnose Infeasibility of Simple 3-DoF Trajectory Optimization
Why not write the equation of motion component-by-component instead: function dydtd2ydt2 = dfu(~,y) g = 9.81; dydtd2ydt2 = ze...

20 days ago | 0

Create a surface with separate contours from other plots
Just concatenate all your n-by-3 data into a large many-by-3 array and then check up the help and documentation of scatteredInte...

20 days ago | 0

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How can I find rank of matrix?
First use pen (pencil) and paper to rewrite your equations into a normal matrix-form: Where M is a 4-by-4 matrix x is an arra...

21 days ago | 1

how to solve 3dof point mass equations of motion of flight vehicle
A three-degrees-of-freedom dynamic system in three spatial coordinates doesn't have yaw and pitch degrees of freedom. It is effe...

21 days ago | 0

Finding intersection between two 3D lines
You can do this rather automatic with geometry and linear algebra if you write your the positions and along lines as: If a...

21 days ago | 0

How to create mono phasic square waves with certain amplitude, pulse width and frequency for a certain time period
you could use square - for details check the help and documentation of that function. HTH.

23 days ago | 0

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Full surface from scatter by griddata!!!
This is "just" a pixellation-problem. You can see how it comes about by varying the resolution of your grid: [xq,yq] = meshgrid...

24 days ago | 1

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How to convert long to scientific e format in plots legend?
You could be a bit more explicit in the call to legend: txt = ['lambda = ',num2str(lambda(check))]; ph = plot(1:100, abs(Arec(...

24 days ago | 0

how to make polar plot with N x M matrix
You can have a look at these file-exchange contributions: pcolor-in-polar-coordinates, perfect-polar-plots, 3d-polar-plot. Or y...

24 days ago | 0

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Mutiple colorbars for mutiple scatter plots in the same figure
Have a look at the file exchange contribution newcolorbar-multiple-colormaps-in-the-same-axes. It seems as it should let you do ...

28 days ago | 0

How to change the colours of bars in a histogram with multiple data
If you take the output from hist and plot that with bar, you can do something like this: [phH1,phH2] = hist([re_low' re_high'],...

28 days ago | 0

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Three nonlinear equation with initial guess
Have a look at the help and documentation of fsolve. That should be the function for this task HTH

28 days ago | 0

Spectral Resampling from hyperspectral to multispectral
If you have a hyper-spectral image, I_hs, on the format [n_y x n_x x n_lambda] and you want to reduce the number of wavelength-c...

30 days ago | 0

2D data fit lsqcurvefit with NaN in grid
You could try doing this with lsqnonlin: x = [1 2 4 6 8 10 13 17 21 25]; y = [0.2 0.5 1 2 4 7 10 14 18 22]; z =[1,0.6844,0.30...

1 month ago | 0

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Calculation of consistent initial conditions for ODE
@Fabio Freschi, OK, now we're at least in the same general region of worrying. If I read decic correctly the use of the QR-outpu...

1 month ago | 0

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