complex.js
function() {

      /**
       * exp(a + i*b) - 1
       = exp(a) * (cos(b) + j*sin(b)) - 1
       = expm1(a)*cos(b) + cosm1(b) + j*exp(a)*sin(b)
       */

      var a = this['re'];
      var b = this['im'];

      return new Complex(
              Math.expm1(a) * Math.cos(b) + cosm1(b),
              Math.exp(a) * Math.sin(b));
    }
function() {

      /**
       * exp(a + i*b) - 1
       = exp(a) * (cos(b) + j*sin(b)) - 1
       = expm1(a)*cos(b) + cosm1(b) + j*exp(a)*sin(b)
       */

      var a = this['re'];
      var b = this['im'];

      return new Complex(
              Math.expm1(a) * Math.cos(b) + cosm1(b),
              Math.exp(a) * Math.sin(b));
    }
function ( ) { /**
       * exp(a + i*b) - 1
       = exp(a) * (cos(b) + j*sin(b)) - 1
       = expm1(a)*cos(b) + cosm1(b) + j*exp(a)*sin(b)
       */ var a = this [ 're' ] ; var b = this [ 'im' ] ; return new Complex ( Math . expm1 ( a ) * Math . cos ( b ) + cosm1 ( b ) , Math . exp ( a ) * Math . sin ( b ) ) ; }
Calculate the complex exponent and subtracts one.

This may be more accurate than `Complex(x).exp().sub(1)` if
`x` is small.

@returns {Complex}
Calculate the complex exponent and subtracts one .