DDRVST2STG(3)
π NAME π
/home/abuild/rpmbuild/BUILD/lapack-static-3.12.0-build/lapack-3.12.0/TESTING/EIG/ddrvst2stg.f
okay so bestie, we're in drvst2stg.f(3) territory β that's the Library Functions Manual btw, and the whole page is literally about this one Fortran file and its favorite child, DDRVST2STG. buckle up π
β¨ SYNOPSIS β¨
Functions/Subroutines
subroutine DDRVST2STGβ(nsizes, nn, ntypes, dotype, iseed, thresh, nounit, a, lda, d1, d2, d3, d4, eveigs, wa1, wa2, wa3, u, ldu, v, tau, z, work, lwork, iwork, liwork, result, info)DDRVST2STGβ yeah she's listed twice, that's just how the index do π
π¦ Function/Subroutine Documentation π¦
subroutine DDRVST2STG
here's the full glow-up of the signature, every single argument, no skips:
subroutine DDRVST2STG (integer nsizes, integer, dimension( * ) nn, integer
ntypes, logical, dimension( * ) dotype, integer, dimension( 4 ) iseed,
double precision thresh, integer nounit, double precision, dimension(
lda, * ) a, integer lda, double precision, dimension( * ) d1, double
precision, dimension( * ) d2, double precision, dimension( * ) d3,
double precision, dimension( * ) d4, double precision, dimension( * )
eveigs, double precision, dimension( * ) wa1, double precision,
dimension( * ) wa2, double precision, dimension( * ) wa3, double
precision, dimension( ldu, * ) u, integer ldu, double precision,
dimension( ldu, * ) v, double precision, dimension( * ) tau, double
precision, dimension( ldu, * ) z, double precision, dimension( * ) work,
integer lwork, integer, dimension( * ) iwork, integer liwork, double
precision, dimension( * ) result, integer info)
and the short version, for the girlies who just want the vibes:
subroutine DDRVST2STG (nsizes, nn, ntypes, dotype, iseed, thresh,
nounit, a, lda, d1, d2, d3, d4, eveigs, wa1, wa2, wa3, u, ldu, v,
tau, z, work, lwork, iwork, liwork, result, info)
π― Purpose
!>!> DDRVST2STG checks the symmetric eigenvalue problem drivers.
periodt. she is the vibe check for the symmetric eigenvalue drivers, and the cast of characters she's testing is iconic β every one of them, in order, no cap:
DSTEVβ computes all eigenvalues and, optionally, eigenvectors of a real symmetric tridiagonal matrix.DSTEVXβ computes selected eigenvalues and, optionally, eigenvectors of a real symmetric tridiagonal matrix.DSTEVRβ computes selected eigenvalues and, optionally, eigenvectors of a real symmetric tridiagonal matrix, using the Relatively Robust Representation where it can.DSYEVβ computes all eigenvalues and, optionally, eigenvectors of a real symmetric matrix.DSYEVXβ computes selected eigenvalues and, optionally, eigenvectors of a real symmetric matrix.DSYEVRβ computes selected eigenvalues and, optionally, eigenvectors of a real symmetric matrix, using the Relatively Robust Representation where it can.DSPEVβ computes all eigenvalues and, optionally, eigenvectors of a real symmetric matrix in packed storage.DSPEVXβ computes selected eigenvalues and, optionally, eigenvectors of a real symmetric matrix in packed storage.DSBEVβ computes all eigenvalues and, optionally, eigenvectors of a real symmetric band matrix.DSBEVXβ computes selected eigenvalues and, optionally, eigenvectors of a real symmetric band matrix.DSYEVDβ computes all eigenvalues and, optionally, eigenvectors of a real symmetric matrix, using a divide and conquer algorithm.DSPEVDβ computes all eigenvalues and, optionally, eigenvectors of a real symmetric matrix in packed storage, using a divide and conquer algorithm.DSBEVDβ computes all eigenvalues and, optionally, eigenvectors of a real symmetric band matrix, using a divide and conquer algorithm.
like... the whole friend group showed up π
so the way this works π β when DDRVST2STG is called, a number of matrix () and a number of matrix are specified. For each size () and each type of matrix, one matrix gets generated and used to test the appropriate drivers. and for each matrix, and each driver routine called, these three tests run:
| A - Z D Z' | / ( |A| n ulp )| I - Z Z' | / ( n ulp )| D1 - D2 | / ( |D1| ulp )
where Z is the matrix of eigenvectors returned when the eigenvector option is given, and D1 and D2 are the eigenvalues returned with and without the eigenvector option. iykyk π«Ά
the sizes are specified by an array NN(1:NSIZES) β each element NN(j) specifies one size. the types are specified by a logical array DOTYPE( 1:NTYPES ) β if DOTYPE(j) is .TRUE., then matrix type will be generated. and currently, the list of possible types is literally:
- The zero matrix.
- The identity matrix.
- A diagonal matrix with evenly spaced eigenvalues
1, ..., ULPand random signs. (ULP = (first number larger than 1) - 1) - A diagonal matrix with geometrically spaced eigenvalues
1, ..., ULPand random signs. - A diagonal matrix with eigenvalues
1, ULP, ..., ULPand random signs. - Same as (4), but multiplied by
SQRT( overflow threshold ) - Same as (4), but multiplied by
SQRT( underflow threshold ) - A matrix of the form
U' D U, whereUis orthogonal andDhas evenly spaced entries1, ..., ULPwith random signs on the diagonal. - A matrix of the form
U' D U, whereUis orthogonal andDhas geometrically spaced entries1, ..., ULPwith random signs on the diagonal. - A matrix of the form
U' D U, whereUis orthogonal andDhas entries1, ULP,..., ULPwith random signs on the diagonal. - Same as (8), but multiplied by
SQRT( overflow threshold ) - Same as (8), but multiplied by
SQRT( underflow threshold ) - Symmetric matrix with random entries chosen from
(-1,1). - Same as (13), but multiplied by
SQRT( overflow threshold ) - Same as (13), but multiplied by
SQRT( underflow threshold ) - A band matrix with half bandwidth randomly chosen between
0andN-1, with evenly spaced eigenvalues1, ..., ULPwith random signs. - Same as (16), but multiplied by
SQRT( overflow threshold ) - Same as (16), but multiplied by
SQRT( underflow threshold )
eighteen whole matrix types?? she's committed π and we're not done β there's more page coming, so don't go anywhere bestie π¦β¨
NSIZESβ INTEGER. The number of sizes of matrices to use. If it's zero,DDRVST2STGliterally does nothing (it's giving unemployed, respectfully π ). It must be at least zero. Not modified.NNβ INTEGER array, dimension (NSIZES). The array holding the sizes to use for the matrices. Zero values get skipped, so don't come for them. The values must be at least zero. Not modified.NTYPESβ INTEGER. The number of elements inDOTYPE. If it's zero,DDRVST2STGdoes nothing again (clocked out, no notes π«Ά). It must be at least zero. If it'sMAXTYP+1andNSIZESis 1, then an extra type gets defined,MAXTYP+1, which is your "just use whatever matrix is already chilling inA" option. That one's only useful ifDOTYPE(1:MAXTYP)is.FALSE.andDOTYPE(MAXTYP+1)is.TRUE.. Not modified.DOTYPEβ LOGICAL array, dimension (NTYPES). IfDOTYPE(j)is.TRUE., then for every size inNNa matrix of that size and of typejwill be generated. IfNTYPESis smaller than the max number of types defined (that'sPARAMETER MAXTYP), then typesNTYPES+1throughMAXTYPjust won't be generated. And ifNTYPESis larger thanMAXTYP, thenDOTYPE(MAXTYP+1)throughDOTYPE(NTYPES)get ignored, they're not beating the allegations. Not modified.ISEEDβ INTEGER array, dimension (4). On entry,ISEEDspecifies the seed of the random number generator β¨. The array elements should be between 0 and 4095; if they're not, they get reduced mod 4096, no cap. Also,ISEED(4)must be odd (bestie, fr fr, keep it odd). The RNG uses a linear congruential sequence limited to small integers, so it should produce machine independent random numbers π. The values ofISEEDchange on exit and can be used in the next call toDDRVST2STGto keep the same random number sequence going. Modified.THRESHβ DOUBLE PRECISION. A test counts as (a fail) if the (error), computed as described above, exceedsTHRESH. The original page is lowkey glitching here and the words are literally missing β that's canon, not me π. Anyway: the error is scaled to beO(1), soTHRESHshould be a reasonably small multiple of 1, e.g., 10 or 100. In particular it should not depend on the precision (single vs. double) or the size of the matrix. Must be at least zero. Not modified.NOUNITβ INTEGER. The FORTRAN unit number for printing out error messages (e.g., if a routine returnsIINFOnot equal to 0). Very "call me if anything goes wrong" energy. Not modified.Aβ DOUBLE PRECISION array, dimension (LDA,max(NN)). Holds the matrix whose eigenvalues are to be computed. On exit,Acontains the last matrix actually used β it keeps the receipts π. Modified.LDAβ INTEGER. The leading dimension ofA. It must be at least 1 and at leastmax( NN ). Not modified.D1β DOUBLE PRECISION array, dimension (max(NN)). The eigenvalues ofA, as computed byDSTEQRsimultaneously withZ. On exit, the eigenvalues inD1correspond with the matrix inA. Modified.D2β DOUBLE PRECISION array, dimension (max(NN)). The eigenvalues ofA, as computed byDSTEQRifZis not computed. On exit, the eigenvalues inD2correspond with the matrix inA. Modified.D3β DOUBLE PRECISION array, dimension (max(NN)). The eigenvalues ofA, as computed byDSTERF. On exit, the eigenvalues inD3correspond with the matrix inA. Modified.D4β DOUBLE PRECISION array, dimension (and then the original just... doesn't say π the dimension field is empty. Iconic of it.)EVEIGSβ DOUBLE PRECISION array, dimension (max(NN)). The eigenvalues as computed byDSTEV('N', ... ). And the author notes, and I quote: "(I reserve the right to change this to the output of whichever algorithm computes the most accurate eigenvalues)." We love a flexible queen π.WA1β DOUBLE PRECISION array, dimension (again, the original leaves this blank π).WA2β DOUBLE PRECISION array, dimension (blank, same deal).WA3β DOUBLE PRECISION array, dimension (blank, same deal).Uβ DOUBLE PRECISION array, dimension (LDU,max(NN)). The orthogonal matrix computed byDSYTRD+DORGTR. Modified.LDUβ INTEGER. The leading dimension ofU,Z, andV. It must be at least 1 and at leastmax( NN ). Not modified.Vβ DOUBLE PRECISION array, dimension (LDU,max(NN)). TheHousholdervectors computed byDSYTRDin reducingAto tridiagonal form (yes the original spells it like that, we stan a typo π). Modified.TAUβ DOUBLE PRECISION array, dimension (max(NN)). The Householder factors computed byDSYTRDin reducingAto tridiagonal form. Modified.Zβ DOUBLE PRECISION array, dimension (LDU,max(NN)). The orthogonal matrix of eigenvectors computed byDSTEQR,DPTEQR, andDSTEIN. Main character matrix energy. Modified.WORKβ DOUBLE PRECISION array, dimension (LWORK). Workspace. Modified.LWORKβ INTEGER. The number of entries inWORK. This must be at least
1 + 4 * Nmax + 2 * Nmax * lg Nmax + 4 * Nmax**2
where Nmax = max( NN(j), 2 ) and lg = log base 2. No shortcuts, bestie, do the math. Not modified.
IWORKβ INTEGER array, dimension (6 + 6*Nmax + 5 * Nmax * lg Nmax) whereNmax = max( NN(j), 2 )andlg = log base 2. Workspace. Modified.RESULTβ DOUBLE PRECISION array, dimension (105). The values computed by the tests described above. Right now the values are limited to1/ulp, to avoid overflow β safety first π¦. Modified.INFOβ INTEGER. If 0, then everything ran OK and we're thriving. Otherwise:-1:NSIZES < 0-2: SomeNN(j) < 0-3:NTYPES < 0-5:THRESH < 0-9:LDA < 1orLDA < NMAX, whereNMAXismax( NN(j) ).-16:LDU < 1orLDU < NMAX.-21:LWORKtoo small.
If DLATMR, DLATMS, DSYTRD, DORGTR, DSTEQR, DSTERF, or DORMTR returns an error code, the absolute value of it is returned. Modified.
πΈ Some Local Variables and Parameters πΈ
ZERO,ONEβ Real 0 and 1. Simple. Elegant. Slay.MAXTYPβ The number of types defined.NTESTβ The number of tests performed, or which can be performed so far, for the current matrix.NTESTTβ The total number of tests performed so far.NMAXβ Largest value inNN.NMATSβ The number of matrices generated so far.NERRSβ The number of tests which have exceededTHRESHso far (computed byDLAFTS).COND,IMODEβ Values to be passed to the matrix generators.ANORMβ Norm ofA; passed to matrix generators.OVFL,UNFLβ Overflow and underflow thresholds.ULP,ULPINVβ Finest relative precision and its inverse.RTOVFL,RTUNFLβ Square roots of the previous 2 values.
The following four arrays decode JTYPE:
KTYPE(j)β The general type (1-10) for type . (the original leaves the type number blank here too, love that for us π)KMODE(j)β TheMODEvalue to be passed to the matrix generator for type . (same blank situation)KMAGN(j)β The order of magnitude (O(1),O(overflow^(1/2) ),O(underflow^(1/2) )
π The tests performed are π
1= | A - U S U' | / ( |A| n ulp )β routine tested:DSTEV('V', ... )2= | I - U U' | / ( n ulp )β routine tested:DSTEV('V', ... )3= |D(with Z) - D(w/o Z)| / (|D| ulp)β routine tested:DSTEV('N', ... )4= | A - U S U' | / ( |A| n ulp )β routine tested:DSTEVX('V','A', ... )5= | I - U U' | / ( n ulp )β routine tested:DSTEVX('V','A', ... )6= |D(with Z) - EVEIGS| / (|D| ulp)β routine tested:DSTEVX('N','A', ... )7= | A - U S U' | / ( |A| n ulp )β routine tested:DSTEVR('V','A', ... )8= | I - U U' | / ( n ulp )β routine tested:DSTEVR('V','A', ... )9= |D(with Z) - EVEIGS| / (|D| ulp)β routine tested:DSTEVR('N','A', ... )10= | A - U S U' | / ( |A| n ulp )β routine tested:DSTEVX('V','I', ... )11= | I - U U' | / ( n ulp )β routine tested:DSTEVX('V','I', ... )12= |D(with Z) - D(w/o Z)| / (|D| ulp)β routine tested:DSTEVX('N','I', ... )13= | A - U S U' | / ( |A| n ulp )β routine tested:DSTEVX('V','V', ... )14= | I - U U' | / ( n ulp )β routine tested:DSTEVX('V','V', ... )15= |D(with Z) - D(w/o Z)| / (|D| ulp)β routine tested:DSTEVX('N','V', ... )16= | A - U S U' | / ( |A| n ulp )β routine tested:DSTEVD('V', ... )17= | I - U U' | / ( n ulp )β routine tested:DSTEVD('V', ... )18= |D(with Z) - EVEIGS| / (|D| ulp)β routine tested:DSTEVD('N', ... )19= | A - U S U' | / ( |A| n ulp )β routine tested:DSTEVR('V','I', ... )20= | I - U U' | / ( n ulp )β routine tested:DSTEVR('V','I', ... )21= |D(with Z) - D(w/o Z)| / (|D| ulp)β routine tested:DSTEVR('N','I', ... )22= | A - U S U' | / ( |A| n ulp )β routine tested:DSTEVR('V','V', ... )23= | I - U U' | / ( n ulp )β routine tested:DSTEVR('V','V', ... )24= |D(with Z) - D(w/o Z)| / (|D| ulp)β routine tested:DSTEVR('N','V', ... )25= | A - U S U' | / ( |A| n ulp )β routine tested:DSYEV('L','V', ... )26= | I - U U' | / ( n ulp )β routine tested:DSYEV('L','V', ... )27= |D(with Z) - D(w/o Z)| / (|D| ulp)β routine tested:DSYEV_2STAGE('L','N', ... )
okay so the test list continues and it's giving "I have 69 tests and I'm not afraid to use them" energy. here's the rest, verbatim, no cap:
!> 28= | A - U S U' | / ( |A| n ulp ) DSYEVX('L','V','A', ... )
!> 29= | I - U U' | / ( n ulp ) DSYEVX('L','V','A', ... )
!> 30= |D(with Z) - D(w/o Z)| / (|D| ulp) DSYEVX_2STAGE('L','N','A', ... )
!> 31= | A - U S U' | / ( |A| n ulp ) DSYEVX('L','V','I', ... )
!> 32= | I - U U' | / ( n ulp ) DSYEVX('L','V','I', ... )
!> 33= |D(with Z) - D(w/o Z)| / (|D| ulp) DSYEVX_2STAGE('L','N','I', ... )
!> 34= | A - U S U' | / ( |A| n ulp ) DSYEVX('L','V','V', ... )
!> 35= | I - U U' | / ( n ulp ) DSYEVX('L','V','V', ... )
!> 36= |D(with Z) - D(w/o Z)| / (|D| ulp) DSYEVX_2STAGE('L','N','V', ... )
!> 37= | A - U S U' | / ( |A| n ulp ) DSPEV('L','V', ... )
!> 38= | I - U U' | / ( n ulp ) DSPEV('L','V', ... )
!> 39= |D(with Z) - D(w/o Z)| / (|D| ulp) DSPEV('L','N', ... )
!> 40= | A - U S U' | / ( |A| n ulp ) DSPEVX('L','V','A', ... )
!> 41= | I - U U' | / ( n ulp ) DSPEVX('L','V','A', ... )
!> 42= |D(with Z) - D(w/o Z)| / (|D| ulp) DSPEVX('L','N','A', ... )
!> 43= | A - U S U' | / ( |A| n ulp ) DSPEVX('L','V','I', ... )
!> 44= | I - U U' | / ( n ulp ) DSPEVX('L','V','I', ... )
!> 45= |D(with Z) - D(w/o Z)| / (|D| ulp) DSPEVX('L','N','I', ... )
!> 46= | A - U S U' | / ( |A| n ulp ) DSPEVX('L','V','V', ... )
!> 47= | I - U U' | / ( n ulp ) DSPEVX('L','V','V', ... )
!> 48= |D(with Z) - D(w/o Z)| / (|D| ulp) DSPEVX('L','N','V', ... )
!> 49= | A - U S U' | / ( |A| n ulp ) DSBEV('L','V', ... )
!> 50= | I - U U' | / ( n ulp ) DSBEV('L','V', ... )
!> 51= |D(with Z) - D(w/o Z)| / (|D| ulp) DSBEV_2STAGE('L','N', ... )
!> 52= | A - U S U' | / ( |A| n ulp ) DSBEVX('L','V','A', ... )
!> 53= | I - U U' | / ( n ulp ) DSBEVX('L','V','A', ... )
!> 54= |D(with Z) - D(w/o Z)| / (|D| ulp) DSBEVX_2STAGE('L','N','A', ... )
!> 55= | A - U S U' | / ( |A| n ulp ) DSBEVX('L','V','I', ... )
!> 56= | I - U U' | / ( n ulp ) DSBEVX('L','V','I', ... )
!> 57= |D(with Z) - D(w/o Z)| / (|D| ulp) DSBEVX_2STAGE('L','N','I', ... )
!> 58= | A - U S U' | / ( |A| n ulp ) DSBEVX('L','V','V', ... )
!> 59= | I - U U' | / ( n ulp ) DSBEVX('L','V','V', ... )
!> 60= |D(with Z) - D(w/o Z)| / (|D| ulp) DSBEVX_2STAGE('L','N','V', ... )
!> 61= | A - U S U' | / ( |A| n ulp ) DSYEVD('L','V', ... )
!> 62= | I - U U' | / ( n ulp ) DSYEVD('L','V', ... )
!> 63= |D(with Z) - D(w/o Z)| / (|D| ulp) DSYEVD_2STAGE('L','N', ... )
!> 64= | A - U S U' | / ( |A| n ulp ) DSPEVD('L','V', ... )
!> 65= | I - U U' | / ( n ulp ) DSPEVD('L','V', ... )
!> 66= |D(with Z) - D(w/o Z)| / (|D| ulp) DSPEVD('L','N', ... )
!> 67= | A - U S U' | / ( |A| n ulp ) DSBEVD('L','V', ... )
!> 68= | I - U U' | / ( n ulp ) DSBEVD('L','V', ... )
!> 69= |D(with Z) - D(w/o Z)| / (|D| ulp) DSBEVD_2STAGE('L','N', ... )
!> 70= | A - U S U' | / ( |A| n ulp ) DSYEVR('L','V','A', ... )
!> 71= | I - U U' | / ( n ulp ) DSYEVR('L','V','A', ... )
!> 72= |D(with Z) - D(w/o Z)| / (|D| ulp) DSYEVR_2STAGE('L','N','A', ... )
!> 73= | A - U S U' | / ( |A| n ulp ) DSYEVR('L','V','I', ... )
!> 74= | I - U U' | / ( n ulp ) DSYEVR('L','V','I', ... )
!> 75= |D(with Z) - D(w/o Z)| / (|D| ulp) DSYEVR_2STAGE('L','N','I', ... )
!> 76= | A - U S U' | / ( |A| n ulp ) DSYEVR('L','V','V', ... )
!> 77= | I - U U' | / ( n ulp ) DSYEVR('L','V','V', ... )
!> 78= |D(with Z) - D(w/o Z)| / (|D| ulp) DSYEVR_2STAGE('L','N','V', ... )
!>
!> Tests 25 through 78 are repeated (as tests 79 through 132)
!> with UPLO='U'
!>
!> To be added in 1999
!>
!> 79= | A - U S U' | / ( |A| n ulp ) DSPEVR('L','V','A', ... )
!> 80= | I - U U' | / ( n ulp ) DSPEVR('L','V','A', ... )
!> 81= |D(with Z) - D(w/o Z)| / (|D| ulp) DSPEVR('L','N','A', ... )
!> 82= | A - U S U' | / ( |A| n ulp ) DSPEVR('L','V','I', ... )
!> 83= | I - U U' | / ( n ulp ) DSPEVR('L','V','I', ... )
!> 84= |D(with Z) - D(w/o Z)| / (|D| ulp) DSPEVR('L','N','I', ... )
!> 85= | A - U S U' | / ( |A| n ulp ) DSPEVR('L','V','V', ... )
!> 86= | I - U U' | / ( n ulp ) DSPEVR('L','V','V', ... )
!> 87= |D(with Z) - D(w/o Z)| / (|D| ulp) DSPEVR('L','N','V', ... )
!> 88= | A - U S U' | / ( |A| n ulp ) DSBEVR('L','V','A', ... )
!> 89= | I - U U' | / ( n ulp ) DSBEVR('L','V','A', ... )
!> 90= |D(with Z) - D(w/o Z)| / (|D| ulp) DSBEVR('L','N','A', ... )
!> 91= | A - U S U' | / ( |A| n ulp ) DSBEVR('L','V','I', ... )
!> 92= | I - U U' | / ( n ulp ) DSBEVR('L','V','I', ... )
!> 93= |D(with Z) - D(w/o Z)| / (|D| ulp) DSBEVR('L','N','I', ... )
!> 94= | A - U S U' | / ( |A| n ulp ) DSBEVR('L','V','V', ... )
!> 95= | I - U U' | / ( n ulp ) DSBEVR('L','V','V', ... )
!> 96= |D(with Z) - D(w/o Z)| / (|D| ulp) DSBEVR('L','N','V', ... )
!>
and yes, it literally says "To be added in 1999" β iconic vintage behavior, we love a retro to-do list. π
Author
- Univ. of Tennessee
- Univ. of California Berkeley
- Univ. of Colorado Denver
- NAG Ltd.
Definition at line 449 of file ddrvst2stg.f.
Author
Generated automatically by Doxygen for LAPACK from the source code.
and that's a wrap, bestie! this page is from LAPACK Version 3.12.0, source file /home/abui...drvst2stg.f(3). slay. π
β¨
π¦ where this page comes from
- opensuse-leap 16.0: lapack-man 3.12.0-160000.2.2 Β· BSD-3-Clause
- opensuse-leap 16.0: lapack-man 3.12.0-160000.2.2 Β· BSD-3-Clause
- opensuse-leap 16.0: lapack-man 3.12.0-160000.2.2 Β· BSD-3-Clause
- opensuse-leap 16.0: lapack-man 3.12.0-160000.2.2 Β· BSD-3-Clause
- π girlified by deepseek-ai/DeepSeek-V4.1-Flash-1017 on : a language model's rewrite of the original, under its terms