How to plot spectrogram on log frequency scale?

I've just starting using the spectrogram function, but I can not get it to plot on a log scale for the frequency axis that mimics the plot generated by logy.

Here's the basic spectrogram I am running:

%%Wv is wave signal of the word shore
% fs = 14700; 
% framelen_samples = (20/1000)*fs;
% noverlap = 0.3* framelen_samples;
% NFFT = 2^nextpow2(framelen_samples);
% spectrogram(Wv,hamming(framelen_samples),floor(noverlap),NFFT,fs,'yaxis');
% colorbar;

Any suggestions?

[alexis]

set(gca,'Yscale','log')

Answer 1

[Star Strider]

You have to get the data spectrogram produces and plot it separately:

T = 0:0.001:2;
X = chirp(T,100,1,200,'q');
[S,F,T] = spectrogram(X,128,120,128,1E3,'yaxis');

figure(1)
surf(T,F,abs(S))
view([0 90])
axis tight
xlabel('Time')
ylabel('Frequency')
set(gca,'YScale','log')
title 'Quadratic chirp'

This is the chirp signal from the spectrogram documentation. See the ‘Examples’ section for the linear scale of the same signal.