How to change the scale of the x-axis & y-axis?

I have written a code which used to plot the spectrogram of a signal. This line was to get the spectrogram:

[s,f2,t] = spectrogram(xc,win,noverlap,FFT_LENGTH,fs,'yaxis');

Then I used imagesc to plot the spectrogram: imagesc(t,f2,20*log10(abs(s)));

Everything is working fine except I want to decrease the scale of the x-axis & y-axis. How can I do that?

[Adam]

Decrease the scale from what to what?

doc xlim
doc ylim

change the axis limits, but I don't know what you mean by 'change the scale', it is very ambiguous. Do you mean change between linear and logarithmic?

Answer 1

[Kevin Chng]

you may use xlimit() or ylimit() to rescale your plot.

https://www.mathworks.com/help/matlab/ref/xlim.html

[Sultan Al-Hammadi]

that's used to set limits, but I actually want to change the scale of x-axis for example (in this case, I want to shrink my graph).

[Kevin Chng]

Shrink your graph?Make your graph/axes/figure look smaller?

[Sultan Al-Hammadi]

What I was trying to say is that how to change the scale for the thing circled by a red line [looks like steps] to make it looks like a straight line (not like steps)? (please see the attached spectrogram)

[Kevin Chng]

Try

h.figure
w = h.Position;
%plot your graph
h.Position = [w(1) w(2) w(3)*1.5 w(4)]

Will it work for you?

Answer 2

[Adam]

doc interp2

is likely what you need if you want finer resolution to get rid of step-like features, but how was anyone to interpret that from you just keep repeating 'change the scale'? You need to be a lot more precise to get a faster answer.

Or since you are creating a spectrogram you could just use a finer discretisation of the frequencies and/or the times used to compute it.

Answer 3

[Aron Magesh]

For changing the axis scale use the following function:

for example low=10,high=100 and interval=5

set(gca,'xtick', 10:5:100)