Implement sparse * diagonal and diagonal * sparse operations, double-prec only. Date: Sun, 8 Mar 2009 16:28:18 -0400 These preserve sparsity, so eye(5) * sprand (5, 5, .2) is *sparse* and not dense. This may affect people who use multiplication by eye() rather than full(). The liboctave routines do *not* check if arguments are scalars in disguise. There is a type problem with checking at that level. I suspect we want diag * "sparse scalar" to stay diagonal, but we have to return a sparse matrix at the liboctave. Rather than worrying about that in liboctave, we cope with it when binding to Octave and return the correct higher-level type. The implementation is in Sparse-diag-op-defs.h rather than Sparse-op-defs.h to limit recompilation. And the implementations are templates rather than macros to produce better compiler errors and debugging information.

      SUBROUTINE ZSHCH(ZR, ZI, CSHR, CSHI, CCHR, CCHI)
C***BEGIN PROLOGUE  ZSHCH
C***REFER TO  ZBESK,ZBESH
C
C     ZSHCH COMPUTES THE COMPLEX HYPERBOLIC FUNCTIONS CSH=SINH(X+I*Y)
C     AND CCH=COSH(X+I*Y), WHERE I**2=-1.
C
C***ROUTINES CALLED  (NONE)
C***END PROLOGUE  ZSHCH
C
      DOUBLE PRECISION CCHI, CCHR, CH, CN, CSHI, CSHR, SH, SN, ZI, ZR,
     * DCOSH, DSINH
      SH = DSINH(ZR)
      CH = DCOSH(ZR)
      SN = DSIN(ZI)
      CN = DCOS(ZI)
      CSHR = SH*CN
      CSHI = CH*SN
      CCHR = CH*CN
      CCHI = SH*SN
      RETURN
      END