how exactly do you get fixed scaling of axes in Matlab plot when plotting inside a loop? My aim is to see how data is evolving inside the loop. I tried using axis manual and axis(...) with no luck. Any suggestions?
I know hold on does the trick, but I don't want to see the old data.
Answer
If you want to see your new plotted data replace the old plotted data, but maintain the same axes limits, you can update the x and y values of the plotted data using the SET command within your loop. Here's a simple example:
hAxes = axes; %# Create a set of axes
hData = plot(hAxes,nan,nan,'*'); %# Initialize a plot object (NaN values will
%# keep it from being displayed for now)
axis(hAxes,[0 2 0 4]); %# Fix your axes limits, with x going from 0
%# to 2 and y going from 0 to 4
for iLoop = 1:200 %# Loop 100 times
set(hData,'XData',2*rand,... %# Set the XData and YData of your plot object
'YData',4*rand); %# to random values in the axes range
drawnow %# Force the graphics to update
end
When you run the above, you will see an asterisk jump around in the axes for a couple of seconds, but the axes limits will stay fixed. You don't have to use the HOLD command because you are just updating an existing plot object, not adding a new one. Even if the new data extends beyond the axes limits, the limits will not change.