Three approaches to selecting a range within a spectogram
1. Simple xlim & ylim
A simple approach that will not result in the loss of data would be to set xlim and ylim.
Demo:
% Full spectrogram
N = 512;
n = 0:N-1;
x = exp(1j*pi*sin(8*n/N)*32);
figure()
spectrogram(x,32,16,64,'centered','yaxis')
title('Full Spectrogram')
rectX = [120 270]; % x limits of selected range
rectY = [-.8 .8]; % y limits of selected range
ax = gca();
axis(ax, 'tight')
rectangle(ax, 'Position', [rectX(1), rectY(1), range(rectX), range(rectY)])
% Limit the visible range
figure()
spectrogram(x,32,16,64,'centered','yaxis')
ax = gca();
rectX = [120 270]; % x limits of selected range
rectY = [-.8 .8]; % y limits of selected range
xlim(ax, rectX)
ylim(ax, rectY)
title('Limited range using xlim & ylim')
2. Maintain DataAspectRatio
figure()
spectrogram(x,32,16,64,'centered','yaxis')
ax = gca();
originalDAR = ax.DataAspectRatio;
rectX = [120 270]; % x limits of selected range
rectY = [-.8 .8]; % y limits of selected range
xlim(ax, rectX)
ylim(ax, rectY)
ax.DataAspectRatio = originalDAR;
title('Maintain data asepct ratio')
3. Maintain the region's area within the figure
figure()
spectrogram(x,32,16,64,'centered','yaxis')
ax = gca();
axis(ax, 'tight')
rectX = [120 270]; % x limits of selected range
rectY = [-.8 .8]; % y limits of selected range
% Scale axis position
axPos = ax.Position;
xl = xlim(ax);
yl = ylim(ax);
xScale = range(rectX)/range(xl);
yScale = range(rectY)/range(yl);
xShift = (rectX(1)-xl(1))/range(xl);
yShift = (rectY(1)-yl(1))/range(yl);
xlim(ax, rectX)
ylim(ax, rectY)
ax.Position(3) = axPos(3)*xScale;
ax.Position(4) = axPos(4)*yScale;
ax.Position(1) = axPos(1) + xShift;
ax.Position(2) = axPos(2) + yShift;
title('Maintain region''s area within the figure')
