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# Bjorn Gustavsson

### UIT, the Arctic University of Norway

Last seen: 2 dagar 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...

3 dagar ago | 0

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

8 dagar 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 dagar 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 dagar 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....

11 dagar 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...

12 dagar 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...

12 dagar 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)...

13 dagar 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 dagar 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 dagar 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 dagar 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...

16 dagar 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...

19 dagar 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....

19 dagar 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 dagar 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 dagar 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...

20 dagar 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...

20 dagar 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 dagar 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.

22 dagar 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...

23 dagar 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(...

23 dagar 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...

23 dagar 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 ...

27 dagar 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'],...

27 dagar 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

27 dagar 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...

29 dagar 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...

30 dagar 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...

ungefär en månad ago | 0

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