function [sum_den]=den(x,vl,table) %%denominator of firing rate formula
sum_den=0;
for i=1:length(table)
sum_den=sum_den+gaussian(norm(table(i,:)-x),vl);
end
end
function [result]=gaussian(x,vl) %truncated gaussian
d=1.5*vl; %distance threshold beyond which is zero
std=vl;
if x<d
exponent=(-0.5 * x)/std; %gaussian value 0 after distance d=1.5 voxels
result=exp(exponent);
else
result=0;
end
end