How to normalize a matrix such that the maximum value is 1?

I have 2 matrices. I plot them against a common x-axis

.

Now I like to normalize both signal such that the largest peak of each signal is 1 so that I can compare the signals.

How should I go about doing it?

Answer 1

[Azzi Abdelmalek]

If you have Image Processing Toolbox

new_y1=mat2gray(y1); 
new_y2=mat2gray(y2);
% new_y1 and new_y2  have both the same minimum equal to 0  and maximum equal to 1

[hithere]

Im not sure if I have Image Processing Toolbox, as Im using an institution computer. How can I check?

[Azzi Abdelmalek]

You can begin by running the code. You can also type in Matlab windows command:

ver

[hithere]

Thanks alot for you help!

Anyway, if i have a matrix 25 x n

How can i normalize it row by row.

So it will normalize row 1, row 2 ... etc. then end up in a 25 x n matrix at the end.

[Azzi Abdelmalek]

out=cell2mat(arrayfun(@(x) mat2gray(A(x,:)),(1:size(A,1))','un',0))

[Thamires Lima]

And, If, do I have an errorbar (y2) associated to y1 how should I write this new errrorbar (new_y2), after normalizing y1 to new_y1?

Answer 2

[Matt J]

signal = signal/norm(signal,inf) ;

Answer 3

[Image Analyst]

What about the min? Do you want that to be mapped to 0, or whatever it ends up being? If it's whatever, then (untested):

y1Normalized = y1 / max(y1);
p1 = subplot(1, 2, 1);
plot(x1, y1Normalized );
% Find what it picked as the nice ranges for the y axis:
yAxis1 = ylim();

y2Normalized = y2 / max(y2);
p2 = subplot(1, 2, 2);
plot(x2, y2Normalized);
% Find what it picked as the nice ranges for the y axis:
yAxis2 = ylim();

% Figure out what the y axis range needs to be to accomodate both plots.
yMin = min([yAxis1, yAxis2]);
yMax = max([yAxis1, yAxis2]);
% Set a common y axis range for both of them.
ylim(p1, [yMin, yMax]);
ylim(p2, [yMin, yMax]);