github.com/gopherd/gonum@v0.0.4/mathext/internal/amos/amoslib/zshch.f (about)

     1        SUBROUTINE ZSHCH(ZR, ZI, CSHR, CSHI, CCHR, CCHI)
     2  C***BEGIN PROLOGUE  ZSHCH
     3  C***REFER TO  ZBESK,ZBESH
     4  C
     5  C     ZSHCH COMPUTES THE COMPLEX HYPERBOLIC FUNCTIONS CSH=SINH(X+I*Y)
     6  C     AND CCH=COSH(X+I*Y), WHERE I**2=-1.
     7  C
     8  C***ROUTINES CALLED  (NONE)
     9  C***END PROLOGUE  ZSHCH
    10  C
    11        DOUBLE PRECISION CCHI, CCHR, CH, CN, CSHI, CSHR, SH, SN, ZI, ZR,
    12       * DCOSH, DSINH
    13        SH = DSINH(ZR)
    14        CH = DCOSH(ZR)
    15        SN = DSIN(ZI)
    16        CN = DCOS(ZI)
    17        CSHR = SH*CN
    18        CSHI = CH*SN
    19        CCHR = CH*CN
    20        CCHI = SH*SN
    21        RETURN
    22        END