While loop not working

Hi

I need help with creating a while loop that works. I have SCADA data which I need to average from 6 sensors, taken at 5 minute intervals. I need to calculate the average of all 6 sensors, find the deviation of each entry from the average and then "discard" values greater than 5%. This calculation needs to continue until none of the entries have a deviation greater than 5% from the average. So far I have come up with the code below, it doesn't seem to be working and I believe it has to do with my condition for starting and ending the while loop. Please help

%Average Pyr Irradiance for the 6 selected pyranometers at Kathu PV

%Clear variables
clear counter;
clear i;
clear j;

%Average data from 5-miute to 15-minute intervals
%Make sure correct monthly data is being analysed

PyrData=zeros(size(Pyr_Mar16,1)/3, size(Pyr_Mar16,2));

counter = 1;
for i=1:3:size(Pyr_Mar16,1)
    for j=1:size(Pyr_Mar16,2)

      K=Pyr_Mar16(i:i+3-1,j);    

      PyrData(counter,j)=mean(K(~isnan(K))); %take the average of all the non "Not-A-Number" values 

      end
  counter=counter + 1;
  end

%Round down any values less than 1 to 0 so that negative and close-to-zero
%numbers are removed

for i=1:size(PyrData,1)
    for j=1:size(PyrData,2)

          if PyrData(i,j)<0.1
              PyrData(i,j)=0;
          end

      end
   end

% Total Average for all pyranometers
RealPyrAvg=zeros(size(PyrData,1),1);
for i=1:size(PyrData,1)
    K=PyrData(i,1:size(PyrData,2));
    RealPyrAvg(i,1) =mean(K(~isnan(K)));
end

%Check Pyranometer Irradiation Deviation and
checkPyrDEV=zeros(size(PyrData,1),size(PyrData,2));
FiveperThresh=zeros(size(PyrData,1),size(PyrData,2));
for i=1:size(PyrData,1)
    countcol=0;
     Z=1;
    for j=1:size(PyrData,2)

          while Z==1
          countcol=countcol+1;
          %Step 1: Check deviation percentage

          if ~isnan(PyrData(i,j))
              checkPyrDEV(i,j)=(abs(PyrData(i,j)-RealPyrAvg(i,1))/RealPyrAvg(i,1))*100;
          else
              checkPyrDEV(i,j)=NaN;
          end

          %Step 2: Flag as 1 if > 5% and 0 if equal to or less than 5%
          if checkPyrDEV(i,j)>5
              FiveperThresh(i,j)=1;
          else
              FiveperThresh(i,j)=0;
          end

          if countcol==size(PyrData,2)

              if sum(FiveperThresh(i,:))>0
                  A=max(checkPyrDEV(i,:));
                  B=find(checkPyrDEV(i,:)==A);
                  PyrData(i,B)=NaN;
                  K=PyrData(i,1:size(PyrData,2));
                  RealPyrAvg(i,1) =mean(K(~isnan(K)));

              elseif sum(FiveperThresh(i,:))==0
                  Z=0;
              end

          end
          end

       end

   end

%Corrected Average

CorrAvgPyr=zeros(size(PyrData,1),1);
for i=1:size(PyrData,1)

      CorrAvgPyr(i,1)=RealPyrAvg(i,1);

end