function concentration = cs(t, cs0)
%CS Soma concentration as a function of time.
% Input function to axon_growth_simulation_with_time_and_space_scaling.m.
% CS defines the soma concentration as a function of original time t. This
% file describes an example soma concentration with jumps between two
% different values. The user should modify this function to fit their
% t: The time point (in original time) to evaluate the soma
% cs0: An optional parameter describing the initial soma concentration.
% Can be used for easy scaling of the soma profile from the main
% concentration: The soma concentration at time point t (original time).
% Erik Henningsson
% March, 2016
% Lund University, Sweden
a = cs0;
b = cs0/4;
period = 2e8;
count = 0;
while t >= 0
t = t - period;
count = count + 1;
if mod(count,2) == 1 || count >= 4
concentration = a;
concentration = b;