REF: Use compute complex

Use compute complex for DRY pruposes

Author: bashtage

randomstate/randomstate.pyx

@@ -1849,12 +1849,8 @@ cdef class RandomState:
                     random_gauss_fill(&self.rng_state, 1, &f_real)
                     random_gauss_fill(&self.rng_state, 1, &f_imag)
 
-                f_imag *= sqrt(1 - f_rho * f_rho)
-                f_imag += f_rho * f_real
-                f_real *= sqrt(0.5 * f_v_real)
-                f_imag *= sqrt(0.5 * f_v_imag)
-                
-                return PyComplex_FromDoubles(floc_r + f_real, floc_i + f_imag)
+                compute_complex(&f_real, &f_imag, floc_r, floc_i, f_v_real, f_v_imag, f_rho)
+                return PyComplex_FromDoubles(f_real, f_imag)
 
             randoms = <np.ndarray>np.empty(size, np.complex128)
             randoms_data = <double *>np.PyArray_DATA(randoms)
@@ -1880,7 +1876,6 @@ cdef class RandomState:
                         randoms_data[j] = floc_r + r_scale * f_real
                         j += 2
 
-
             return randoms
 
         gpc = ogamma + orelation