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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.
author Jason Riedy <jason@acm.org>
date Mon, 09 Mar 2009 17:49:13 -0400
parents 82be108cc558
children
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      SUBROUTINE CBUNK(Z, FNU, KODE, MR, N, Y, NZ, TOL, ELIM, ALIM)
C***BEGIN PROLOGUE  CBUNK
C***REFER TO  CBESK,CBESH
C
C     CBUNK COMPUTES THE K BESSEL FUNCTION FOR FNU.GT.FNUL.
C     ACCORDING TO THE UNIFORM ASYMPTOTIC EXPANSION FOR K(FNU,Z)
C     IN CUNK1 AND THE EXPANSION FOR H(2,FNU,Z) IN CUNK2
C
C***ROUTINES CALLED  CUNK1,CUNK2
C***END PROLOGUE  CBUNK
      COMPLEX Y, Z
      REAL ALIM, AX, AY, ELIM, FNU, TOL, XX, YY
      INTEGER KODE, MR, N, NZ
      DIMENSION Y(N)
      NZ = 0
      XX = REAL(Z)
      YY = AIMAG(Z)
      AX = ABS(XX)*1.7321E0
      AY = ABS(YY)
      IF (AY.GT.AX) GO TO 10
C-----------------------------------------------------------------------
C     ASYMPTOTIC EXPANSION FOR K(FNU,Z) FOR LARGE FNU APPLIED IN
C     -PI/3.LE.ARG(Z).LE.PI/3
C-----------------------------------------------------------------------
      CALL CUNK1(Z, FNU, KODE, MR, N, Y, NZ, TOL, ELIM, ALIM)
      GO TO 20
   10 CONTINUE
C-----------------------------------------------------------------------
C     ASYMPTOTIC EXPANSION FOR H(2,FNU,Z*EXP(M*HPI)) FOR LARGE FNU
C     APPLIED IN PI/3.LT.ABS(ARG(Z)).LE.PI/2 WHERE M=+I OR -I
C     AND HPI=PI/2
C-----------------------------------------------------------------------
      CALL CUNK2(Z, FNU, KODE, MR, N, Y, NZ, TOL, ELIM, ALIM)
   20 CONTINUE
      RETURN
      END