dec2hex (Matlab function) Decimal to hexadecimal number conversion

## Matlab/Scilab equivalent

Matlab | Scilab
    dec2hex
    dec2hex

## Particular cases

Empty matrix input:

  In Matlab dec2hex returns "" when input is [] but Scilab dec2hex returns [].

Complex inputs:

  In Matlab dec2hex automatically removes complex part of input but not in Scilab.

Two inputs:

  In Matlab dec2hex can have two inputs, in Scilab mtlb_dec2hex emulates this case.