asech
Inverse hyperbolic secant.
y=asech(x)
Inputs
x An array of real or complex numbers.
Outputs
y An array of same size as x . Each element of the output is the inverse hyperbolic secant of the corresponding element of the input.


Example
>>a=complexRandn(2,3)
>>s=sech(a)
>>as=asech(s)
>>a
      -0.4376 -      0.483i         -0.5339 +     1.4239i          0.1282 +     0.3776i   
       0.3364 +     0.1496i         -0.0047 -     0.3858i          0.4737 -     0.1015i   

>>as
       0.4376 +      0.483i          0.5339 -     1.4239i          0.1282 +     0.3776i   
       0.3364 +     0.1496i          0.0047 +     0.3858i          0.4737 -     0.1015i   

>>norm(sech(a)-sech(as))
       3.3307e-016