As a reference, Matlab functions can only return a single output variable; the alternate return syntax is simply not supported.
Call the function and save the variables in another variable first before calling grpstats is the only option.
BTW, in your function, I'd compute a logical vector and use it instead of doing the test twice...
function [CutOffMean, CutOffStd] = CutOffForPctile(InData, Pctile)
CutOff = prctile(InData,Pctile);
idx=InData<=CutOff;
CutOffMean = mean(InData(idx));
CutOffStd = std(InData(idx));
end
Not sure if the JIT optimizer can find the common expression or not...
ADDENDUM
OK, I admit my lack of familiarity with grpstats led me to not fully consider the use of the function handle; I was thinking one could simply substitute a set of values; clearly that isn't so, agreed...
Checking with the documentation for grpstats, a valid function to use a function handle for additional statistics in grpstats must return either a column vector or an array of nvals-by- ncols. So, I think you need to rewrite your function as
function [CutOffStats] = CutOffForPctile(InData, Pctile)
CutOff = prctile(InData,Pctile);
idx=InData<=CutOff;
CutOffstats = [mean(InData(idx));
std(InData(idx))];
end
You'll need to ensure proper orientation of InData, of course, so that variables are by column and the statistics are row vectors.
