Matlab stuck at Warning about Integers

Hi people,

I need help. I'm running a code and I am getting stuck at line 51 that reads:

sortedData = sort(cutData(tstart:tend));
baseline = median(sortedData(1:((0.2)*length(cutData(tstart:tend)))));
deltaF(i) = (cutData(i) - baseline)/baseline;

This is the message I keep getting:

> In scrapAnalysis (line 51)

Warning: Integer operands are required for colon operator when used as index

[Walter Roberson]

length(cutData(tstart:tend) is going to be the same as tend-tstart+1 . But suppose that does not happen to be an exact multiple of 5, so 0.2 times the value does not turn out to be an integer?

Answer 1

[Fangjun Jiang]

With this, do you get it?

>> a=rand(1,100);
>> b=a(2:10);
>> c=a(2:0.9:10);
Warning: Integer operands are required for colon operator when used as index. 

Answer 2

[Star Strider]

Without knowing more about ‘cutData’, it’s difficult to provide a specific solution. Subscripts must be integers greater than 0, or logicals

Assuming that ‘t’ is your time vector associated with ‘cutData’, try this:

tstart =  ...;
tend = ...;
idx1 = find(t >= tstart, 1, 'first');
idx2 = find(t <= tend, 1, 'last');
sortedData = sort(cutData(idx1:idx2));

Something like that should do what you want. You will have to experiment with it with your code.

Answer 3

[Mark Dawnson]

Thanks for all the answers. I'll try these and let you know !

[Star Strider]

It would also help to know the complete error message. (Please copy all the red text in your Command Window and paste it to a Comment here).

There are at least two lines that could be throwing that error. We have no idea which one it is.