image/ imagesc of matrix

Hi,

I couldn't figure out how to use "image" or "imagesc" to plot my data, hope you can give me a hint on this issue:

My data consist of collected data over time for several experiments (e.g 100): X1=f(t); ....; X100=f(t)

if i create a matrix as A=[X1;X2;X3;...;X100]; then using " Image(A)" , will give a color plot which y-axis is number of experiments (here 100), x-axis is number of data (length of Xi), and color indicates value of X .

My question:

what i need to do : to change x-axis to value of time, instead of numbering length of X? ( X and Time vector have the same length)

Thanks in advance,

Answer 1

[Junaid]

could you share your code.

For quick answer. You can change the x label by this.

xlabel('This is the label caption');

and if you want to change the Ticks values, then ;

set(gca,'XTick',[1:5]);% something like this

in above command, your X tick values will be from 1 to 5, you can set as you like.

[karlo gonzales]

Hi,

Thanks Junaid for your reply. but it doesn't work that way. consider

A=randn(100,200);  T=linespace(1,10,200); imagesc(A)

 set( gca,'XTick', T );

will not generate the image i was looking for! or maybe i misunderstood your suggestion.

[Junaid]

A=randn(100,200);  T=linspace(1,40,200); 
imagesc(A)
   datefmt = 'HH:MM';  %adjust as appropriate
  xticks = 1:20:200;  %adjust as appropriate, positive integers only
  xlabels = cellstr( datestr( T(xticks), datefmt ) );  %time labels
  % xlabels = num2str( ( T(xticks)) ); % you don't need this 
  set(gca, 'XTick', 1:20:200, 'XTickLabel', xlabels);

Now try, as you were contaminating the xlabels. I hope this works now.

Answer 2

[Walter Roberson]

datefmt = 'HH:MM';  %adjust as appropriate
xticks = 1:10:100;  %adjust as appropriate, positive integers only
xlabels = cellstr( datestr( MyTimeVector(Xticks), datefmt ) );  %time labels
set(gca, 'XTick', 1:10:100, 'XTickLabel', xlabels);

[karlo gonzales]

unfortunately, still i couldn't get the good result from the cods

A=randn(100,200);  T=linspace(1,40,200); 
imagesc(A)

   datefmt = 'HH:MM';  %adjust as appropriate
  xticks = 1:20:200;  %adjust as appropriate, positive integers only
  xlabels = cellstr( datestr( T(xticks), datefmt ) );  %time labels
  xlabels = num2str( ( T(xticks)) );
  set(gca, 'XTick', 1:20:200, 'XTickLabel', xlabels);

any idea, what's wrong here?