Index exceeds matrix dimensions.

I get error message 'Index exceeds matrix dimensions' wiht the following code. I will appreciate help.

for i = 1:length( Vmean ),
     GroupMean = GroupMean + Vmean{i}.Y(1,strt:fnsh);
     GroupStd = GroupStd   + Vstd{i}.Y(1,strt:fnsh);

Answer 1

[Matt J]

"fnsh" is greater than the length of either Vmean{i}.Y or Vstd{i}.Y

Hence, there is nothing there for Vmean{i}.Y(fnsh) or or Vstd{i}.Y(fnsh) to grab.

Use

      >>dbstop if error

to find the offending i.

[Rajendra]

Thanks.. can you suggets a fix?

[Matt J]

I suggested that you use DBSTOP, which should have led you to the fix.

[Rajendra]

Thanks Matt. I changed the script to: GroupMean = GroupMean ./ length( Vmean ); GroupStd = GroupStd ./ length(Vmean ); It resolved the issue at this point but get another error message downstream the following script:

oldTimes = [ (min(V.start_times ) - .5 ) ... (V.start_times + .5 * duration) ... (max(V.start_times + duration ) + .5 ) ];

Error: Error using + Matrix dimensions must agree.

Error in interpT_VOL (line 26) oldTimes = [ (min(V.start_times ) - .5 ) ...

I think matrix dimensions are OK. I will very much appreciate any suggestion.

Answer 2

[Image Analyst]

I suggest you make fnsh not more than the number of columns in Y. What does this say

theYarray = Vmean{1}.Y;
whos theYarray

The whos command will tell you how many rows and columns are in Y. See if the number of columns is less than fnsh. If it is, then you need to figure out why you're trying to specify fnsh with the value that you did.

Here's another suggestion: http://blogs.mathworks.com/videos/2012/07/03/debugging-in-matlab/

[Rajendra]

Thanks.. for some reason it resturns error message: Undefined variable "V.mean". I however chnaged the script and as mentioned above, got another message. I am copying my comment above: I changed the script to: GroupMean = GroupMean ./ length( Vmean ); GroupStd = GroupStd ./ length(Vmean ); It resolved the issue at this point but get another error message downstream the following script:

oldTimes = [ (min(V.start_times ) - .5 ) ... (V.start_times + .5 * duration) ... (max(V.start_times + duration ) + .5 ) ];

Error: Error using + Matrix dimensions must agree.

Error in interpT_VOL (line 26) oldTimes = [ (min(V.start_times ) - .5 ) ...

I think matrix dimensions are OK. I will very much appreciate any suggestion.

[Rajendra]

oldTimes = [(min(V.start_times ) - .5 ) ...
             (V.start_times + .5 * duration) ...
             (max(V.start_times + duration ) + .5 ) ];

[Rajendra]

This is the code which is returning the matrix error

[Image Analyst]

You called it Vmean, not V.mean. Anyway, did you try my second/last suggestion (the link)?

[Rajendra]

I did try the tips on the link.. very helpful but still not easy to locate the probelm when you are dealing with multiple scripts.. if you think there is no syntazx error in the code, I will keep looking for pther leads.. it is frustrating. I very much appreciate your help though..

[Image Analyst]

We can't really do much more unless you upload the program and the data so we can then use the debugger to step through your code (same as what I asked you to do). Using the debugger and finding out what the dimensions and indexes are is the way to solve this problem. If you can't do it then we/someone might do it for you but we require code and data.