plotting multiple histograms from data saved as double

hey guys..

I am trying to get 30 subplots with each 3 (differently coloured) histograms from column 1:3 of each row of the attached dataset saved as double.

tried hist but this wouldnt let me change the colour....histogram didnt work with double/cell array i think.

I am new to matlab...anyone could help? using matlab 2019b.

thanks!

Answer 1

[Ameer Hamza]

There are 29 rows in the cell array you attached.

colors = [1 0 0;
          0 1 0;
          0 0 1];
fig = figure();
ax = gobjects(1, 30);
for i = 1:size(P_RTpertrial,1)
    ax(i) = subplot(10,3,i);
    hold(ax(i));
    for j = 1:size(M, 2)
        histogram(P_RTpertrial{i,j}, 'FaceColor', colors(j,:), 'FaceAlpha', 0.3);
    end
end
fig.WindowState = 'maximized';

[Steffi]

hey thanks a lot for your answer...

hmmm unfortunately I get an error code "Error using histogram, Too many input arguments."

also I wonder...they should all look different...

is it ...

M = [P_RTpertrial{i,:}]; ?

but even then I get an error in the histogram line...(see above)

grrrr

[Ameer Hamza]

Yes, you are correct. It should have been

M = [P_RTpertrial{i,:}];

but this won't work because matrices have a different number of rows. I have updated the code, try it now.

[Steffi]

I have now also replace M with P_RTpertrial....but I still get "Error using histogram, Too many input arguments." when I get to the "histogram"-line. :(

[Ameer Hamza]

Can you show the output of

which histogram

[Steffi]

shows me the path to the following file:

function [result,descriptor]=histogram(x,descriptor)

% HISTOGRAM Computes the frequency histogram of the row vector x.

% [RESULT,DESCRIPTOR] = HISTOGRAM(X) or

% [RESULT,DESCRIPTOR] = HISTOGRAM(X,DESCRIPTOR) or

%where

% DESCRIPTOR = [LOWER,UPPER,NCELL]

%

% RESULT : A row vector containing the histogram

% DESCRIPTOR: The used descriptor

%

%   X         : The row vector be analyzed
%   DESCRIPTOR: The descriptor of the histogram
%     LOWER   : The lowerbound of the histogram
%     UPPER   : The upperbound of the histogram
%     NCELL   : The number of cells of the histogram
%
%   See also: http://www.cs.rug.nl/~rudy/matlab/
 
%   R. Moddemeijer 
%   Copyright (c) by R. Moddemeijer
%   $Revision: 1.2 $  $Date: 2001/02/05 09:54:29 $
 
 
if nargin <1
   disp('Usage: RESULT = HISTOGRAM(X)')
   disp('       RESULT = HISTOGRAM(X,DESCRIPTOR)')
   disp('Where: DESCRIPTOR = [LOWER,UPPER,NCELL]')
   return
end
 
% Some initial tests on the input arguments
 
[NRowX,NColX]=size(x);
 
if NRowX~=1
  error('Invalid dimension of X');
end;
 
if nargin>2
  error('Too many arguments');
end;
 
if nargin==1
  minx=min(x);
  maxx=max(x);
  delta=(maxx-minx)/(length(x)-1);
  ncell=ceil(sqrt(length(x)));
  descriptor=[minx-delta/2,maxx+delta/2,ncell];
end;
 
lower=descriptor(1);
upper=descriptor(2);
ncell=descriptor(3);
 
if ncell<1 
  error('Invalid number of cells')
end;
 
if upper<=lower
  error('Invalid bounds')
end;
 
result(1:ncell)=0;
 
y=round( (x-lower)/(upper-lower)*ncell + 1/2 );
for n=1:NColX
  index=y(n);
  if index >= 1 & index<=ncell
    result(index)=result(index)+1;
  end;
end;
 

[Ameer Hamza]

This doesn't seem like the file provided by MATLAB. Have you placed some other function named histogram in MATLAB's path?

[Steffi]

got this version from my colleauges...have looked online to download the original version....but didnt find anything...do you know where to best get it?

[Ameer Hamza]

You cannot get it online. This only comes with the installation of MATLAB. Does the path shows that it lies somewhere like

C:\....\MATLAB\toolbox\....

or the file is placed somewhere else?

[Steffi]

just downloaded new matlab version including toolbox and it works perfectly well now!

thanks a million!

[Ameer Hamza]

Glad to be of help.