NAME

zoptimal_workspace - Get the optimal amount of workspace for the last routine called that supports varying length

#include <sunperf.h>

double complex workspace. 
 

SYNOPSIS

doublecomplex ∗zoptimal_workspace(void);

PURPOSE

Many LAPACK routines require workspace parameters to provide temporary storage for intermediate results.  Some routines allow varying amounts of workspace to be passed in.  A choice is made between multiple algorithms, using the most efficient method which can operate given the amount of workspace.  The following lapack routines all support varying amounts of real workspace:
 
cgebrd    cgees     cgeesx    cgeev     cgeevx
cgegs     cgegv     cgehrd    cgelqf    cgels
cgelss    cgeqlf    cgeqrf    cgerqf    cgesvd
cgetri    cggglm    cgglse    cggqrf    cggrqf
chbevd    cheev     cheevd    cheevx    chegv
chesv     chesvx    chetrd    chetrf    chgeqz
chpevd    chseqr    clarfb    cstedc    csysv
csysvx    csytrf    ctrsen    ctrsna    cungbr
cunghr    cunglq    cungql    cungqr    cungrq
cungtr    cunmbr    cunmhr    cunmlq    cunmql
cunmqr    cunmrq    cunmtr    dgebrd    dgees
dgeesx    dgeev     dgeevx    dgegs     dgegv
dgehrd    dgelqf    dgels     dgelss    dgeqlf
dgeqrf    dgerqf    dgesvd    dgetri    dggglm
dgglse    dggqrf    dggrqf    dhgeqz    dhseqr
dlarfb    dorgbr    dorghr    dorglq    dorgql
dorgqr    dorgrq    dorgtr    dormbr    dormhr
dormlq    dormql    dormqr    dormrq    dormtr
dsbevd    dspevd    dstedc    dstevd    dsyev
dsyevd    dsyevx    dsygv     dsysv     dsysvx
dsytrd    dsytrf    dtrsen    dtrsna    sgebrd
sgees     sgeesx    sgeev     sgeevx    sgegs
sgegv     sgehrd    sgelqf    sgels     sgelss
sgeqlf    sgeqrf    sgerqf    sgesvd    sgetri
sggglm    sgglse    sggqrf    sggrqf    shgeqz
shseqr    slarfb    sorgbr    sorghr    sorglq
sorgql    sorgqr    sorgrq    sorgtr    sormbr
sormhr    sormlq    sormql    sormqr    sormrq
sormtr    ssbevd    sspevd    sstedc    sstevd
ssyev     ssyevd    ssyevx    ssygv     ssysv
ssysvx    ssytrd    ssytrf    strsen    strsna
zgebrd    zgees     zgeesx    zgeev     zgeevx
zgegs     zgegv     zgehrd    zgelqf    zgels
zgelss    zgeqlf    zgeqrf    zgerqf    zgesvd
zgetri    zggglm    zgglse    zggqrf    zggrqf
zhbevd    zheev     zheevd    zheevx    zhegv
zhesv     zhesvx    zhetrd    zhetrf    zhgeqz
zhpevd    zhseqr    zlarfb    zstedc    zsysv
zsysvx    zsytrf    ztrsen    ztrsna    zungbr
zunghr    zunglq    zungql    zungqr    zungrq
zungtr    zunmbr    zunmhr    zunmlq    zunmql
zunmqr    zunmrq    zunmtr
 
The C LAPACK interfaces do not require the user to provide workspace.  Tempory storage is dynamically allocated as needed.  By default, the C interfaces use the minimum amount of storage required.  Therefore, the computation for the routines listed above will use the algorithm that requires the least amount of workspace.  In most cases these algorithms require more time.  A larger block of memory can be supplied with the use_workspace function, allowing more time-efficient algorithms to be selected.
 
When a LAPACK routine is called that supports varying length real or complex workspaces, the optimal amount of workspace necessary is returned in the first element of the workspace. This value can be obtained for the last routine that had double complex workspace with a call to zoptimal_workspace.

SunOS WorkShop_5.0  —  Last change: 10 Dec 1998