MATLAB: How to decrease the number of points in a matrix

Question

Good day! So here's my code for project:

psdn = 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figure (1)
plot (psdn)
grid on
xlabel ('Frequency in kHz')
ylabel ('Power Spectral Density in dbm/kHz')
title ('Background Noise')

The size of the matrix is 1000×1, but I want to decrease the number of points into 128 points only, i.e. the desired size of the matrix is 128×1 and I still want the same figure (just a more "pixelated" version of the original one). How am I going to do this?

Answer 1

I suggest http://www.mathworks.com/help/matlab/ref/spline.html

x = 1 : length(psdn);
x128 = linspace(x(1), x(end), 128);
p128 = spline(x, psdn, x128);
plot(x128, p128);