how to find max and min values of the plot

Hi,

Im plotting some data and I want to separate sections with colours. I am doing that with 'patch' but i want it to fill to maximal and minimal value of the plot window, for a section of the x-axis that I choose. My code:

figure; hold on;
I1 = power(7000:end);
t1 = time(7000:end);
plot(t1,I1,'.'); grid; 
time1 = '15:48:30';
time2 = '15:51:30';
p=patch([datenum(time1,'HH:MM:SS') datenum(time2,'HH:MM:SS') ...
    datenum(time2,'HH:MM:SS') datenum(time1,'HH:MM:SS')],...
    [0.06 0.06 0.105 0.105],'r'); % x, Y coord
  set(p,'FaceAlpha',0.1);

I don't want to enter these numbers manually. How can it find the max and min the plot with plot the data with and automatically size the patch to fill along the y-axis for entered x values?

Answer 1

[Guillaume]

You can get the axis range from its XLim and YLim properties, which you can query with either get(gca, 'YLim') or simply ylim:

p = patch([datenum(time1,'HH:MM:SS') datenum(time2,'HH:MM:SS') ...
  datenum(time2,'HH:MM:SS') datenum(time1,'HH:MM:SS')],...
  reshape([ylim; ylim], 1, []),'r');

[captainmariah]

Hi, Im getting the following error when using this code: reshape([ylim; ylim], 1, []),'r');

Error: File: processdata.m Line: 46 Column: 48 Expression or statement is incorrect--possibly unbalanced (, {, or [.