Computes the psi function for real arguments. The psi
function takes only a single argument
y = psi(x)
where x
is either a float
or double
array. The output
vector y
is the same size (and type) as x
.
The psi function is defined as
and for integer arguments, is equivalent to the factorial function.
Here is a plot of the psi function over the range [-5,5]
.
--> x = linspace(-5,5); --> y = psi(x); --> plot(x,y); xlabel('x'); ylabel('psi(x)');
which results in the following plot.