function [top,bot,lft,rgt] = halfspot_fluc(M,spotr,spotc,thresh)
%HALFSPOT_FLUC Inputs a 3D array of Hartmann sensor images, along with an
%approximate spot location and intensity threshhold. Finds a spot on the
%first image near (spotc,spotr) and defines boundary of spot near an
%intensity of 'thresh'. Outputs fluctuations of the intensity sums of the
%top, bottom, left and right halves of the spot about their means, and
%graphs these against each other automatically.

[I,r0,c0]=spotfind(M,thresh,spotr,spotc);
[r,c]=singspotcent(I);
[top,bot,lft,rgt]=hemiadd(I,r,c)

subplot(2,1,1)
title(['Spot centered at (' num2str(round(c0+c)) ',' num2str(round(r0+r)) '):' 'Intensity Deviation of Top/Bottoms Halves'])
end