function [topsum,botsum,leftsum,ritsum] = hemiadd(MB,rcd,ccd)
%HEMIADD inputs a 3D image matrix and centroid location and finds the difference of
%the sums of the top half, bottom half, left half and right half at each time
%compared to their means over that time

%round coordinates of centroid
rc=round(rcd);
cc=round(ccd);

%subtract approximate background
M=abs(MB-mean(mean(min(MB))));

%initialize values
[rn,cn,tn]=size(M);
t=1;
topsum=[];
botsum=[];
leftsum=[];
ritsum=[];

%sum each half-plane for each image
while t<(tn+1)
topM=M(1:(rc-1),:,t);
botM=M((rc+1):rn,:,t);
lftM=M(:,1:(cn-1),t);
ritM=M(:,(cc+1):cn,t);
topsum=cat(1,topsum,sum(sum(topM)));
botsum=cat(1,botsum,sum(sum(botM)));
leftsum=cat(1,leftsum,sum(sum(lftM)));
ritsum=cat(1,ritsum,sum(sum(ritM)));
t=t+1;
end
topsum=topsum-mean(topsum);
botsum=botsum-mean(botsum);
leftsum=leftsum-mean(leftsum);
ritsum=ritsum-mean(ritsum);

%Plot and Label
subplot(2,1,1)
plot(topsum)
hold;
plot(botsum,'Color','Red')
hold;
subplot(2,1,2)
plot(leftsum)
hold;
plot(ritsum,'Color','Red')
hold;
subplot(2,1,1)
title('Intensity Deviation of Top/Bottoms Halves')
xlabel('Time(arb. units)')
ylabel('Diff. of intensity from mean (arb units)')
legend('Top Half','Bottom Half')
subplot(2,1,2)
title('Intensity Deviation of Left/Right Halves')
xlabel('Time(arb. units)')
ylabel('Diff. of intensity from mean (arb units)')
legend('Left Half', 'Right Half')
end