How to extract the maximum value of an area of a figure?

I have a figuret that I want to extract the maximum value fro

m a particular area on the plot from. I am quite new to matlab and have searched online for help but cannot find a way round this problem.

My current code to extract the area I want is

% Load file
load opfile.mat

% open figure
open opfile.fig
hold on
fig = gcf;

zoomedpoint = rectangle('Position',[491075 492065 4384740 4385580]);
axis([491075 492065 4384740 4385580]);
% Save the plot
saveas(gcf, 'zoomedpoint.fig')

This produces a figure of the selcted area but I cannot seem to extacct the maximum value from this.

I have also tried using the below lin eof code; however, when entered it comes up with the below error, despite these being the values I used to create the figure.

"Index in position 1 exceeds array bounds. Index must not exceed 988.

Error in Fig4_analysis (line 24)

mHs = max(hrms(491075:492065,438474:438558));"

mHs = max(hrms(491075:492065,438474:438558));

Any help would be very much approcated. Thank you

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Answer 1

[Mathieu NOE]

hello

so your data is a matrix (hrms)

what is the dimension of hrms ? you are probably confused between the range of that you want to display (hrms) and the size of the data , which is generating the error

So it may be worth to share as well the mat & fig files along with your code.

FYI , you can find the row and column index of the max value by this method :

• here in my example the data matrix is A
• M is the max value of A and row and col are the x, y indexes of the max value (if you need them)
• of course , M = A(row,col) , you can double check !

A = [1 2 3; 7 8 9]  % dummy data matrix
[M,ind] = max(A,[],'all','linear') % max value of matrix 
[row,col] = ind2sub(size(A),ind) ; % Convert linear indices to subscripts

So , in your code , you can do :

A = hrms(491075:492065,438474:438558);  % !! check for indexes here !!
[M,ind] = max(A,[],'all','linear') % max value of matrix 
[row,col] = ind2sub(size(A),ind) ; % Convert linear indices to subscripts