Error in script Subscript indices must either be real positive integers or logicals.

I am trying to calculate the mean, max and min values from an array under some condition and at some specific case i get a very "strange" error

Subscript indices must either be real positive integers or logicals.

Error in MeanHourlyTOC (line 31)
                minTOC = min(dummy);

since i am able to calculate the max and mean values and this error is referred just in the min value. My code is as follow

l=0;

for i=1982:2012
    for j=1:12
        for k=1:24

              idx=find(Yr==i&M==j&T==k);
              dummy=TOC(idx);
              dummy(isnan(dummy))=[];

              if ~isempty(dummy)
                  l=l+1;
                  mTOC = mean(dummy);
                  sTOC = std(dummy);
                  maxTOC = max(dummy);
                  minTOC = min(dummy);
                  dy = decyear(i,j,15,k,0,0);
                  Output.hTOCMonthlyMean(l,:) = [dy i j k mTOC sTOC maxTOC minTOC length(dummy)];
              end
          end
      end
  end

and the moment the script terminates the array dummy is

>> dummy

dummy =

    368.8352
    334.5709
    341.9396

I would appreciate any help to resolve this issue

Answer 1

[Matt J]

Put

clear min

just prior to the for-loop. Preferably also, avoid using "min" as the name of one of your variables.

[Kostas]

Thanks a lot it worked!

Answer 2

[Adam]

Do you have a variable named min further up the code?

The error message is typical of such a scenario where the code thinks that the instruction

minTOC = min(dummy);

is trying to index into a variable called 'min' using whatever is in dummy as indices rather than call the 'min' function.

Variables always take precedence over functions and will hide them if you reuse the name of a function as a variable.

which min

at the appropriate point will tell you whether you have such a variable. If you don't it will point you to where the builtin function is, if you have a variable it will just say:

min is a variable.

[Kostas]

Thank you for your reply, i had no variable called min. When i used the option

clear min

as Matt J suggested, then my script worked fine

[Adam]

That is interesting.

clear min

would normally clear a variable called min and thus work in that way. It would also clear any other functions and other detritus in its cache called min, but that is quite surprising that you got such behaviour with no variable called min.

[Matt J]

I am skeptical that Kostas did not have a variable called 'min'.