Select part of a signal

Hello,

I have a 6xN matrix and a 1 dimension vector (made of 0 and 1) (ex: 000000000000000111110000000000.) I need to select part of the matrix, in correspondence of the "1" in the vector. (they temporally start together), and divide the selected signal in blocks.

What I have is:

DStimData = diff(round(StimData)); 

blockonoff = find(DStimData~=0);

%Where StimData is my "1-0" vector.

blockonoff = blockonoff(find(flagblockonoff));

          trialonset = intersect(find(DStimData>0),blockonoff);
          trialoffset = intersect(find(DStimData<-0),blockonoff);

          t = 1;

          for k = 1:length(trialonset)

              onsettime = trialonset(k);
              OffOnDiff = trialoffset - onsettime;
              GoodOffset = trialoffset(find(OffOnDiff>0));
              if ~isempty(GoodOffset),
                  offsettime = min(GoodOffset);
                  onsettime = onsettime + 1;
                  segmentONtime = max(1,onsettime-pretimeN);
                  segmentOFFtime = min(offsettime+posttimeN,size(ForceData,2));
                  segmentlength = segmentOFFtime - segmentONtime + 1;

On these parts of signal I apply my analysis.

Now I need an improvement: after plotting my selected signal, in some cases, I need to do the analysis again, excluding some part of the signal, even when the "1" is present. How can I be more flexible in the selection of my signal? Is there a better way also to improve the old code?

Thank You in advance