Sat down with someone and worked it out together:
num_rows = length(a); num_columns = 22;
b = zeros(num_rows,num_columns); c = zeros(num_rows,num_columns);
for i = 1:num_rows
count = a(i,13);
int_c(i,:) = (0:1/(num_columns - 1):1)*c(i,count);
int_b(i,:) = interp1(b(i,1:count), b(i,1:count), new_thick(i,:),'spline');
end
end