The function has two components, y[1] decreasing and y[2] increasing.
For
0 &le t < t_relax y[1] decreases exponentially from 1 to 0 y[2] increases exponentially from 0 to 1For
t < 0 and t &ge t_relax y[1] = 0 y[2] = 1i.e. for negative t y takes its asymptotic values.
function relaxation
extends Icons.Function;
input Real t "relative time";
input Real t_char "charcteristic time";
input Real beta(min = 2) "power of exponent";
output Real[2] y "relaxation function {decreasing, increasing}";
end relaxation;