table of contents
| la_constants(3) | LAPACK | la_constants(3) | 
NAME¶
la_constants - LA_CONSTANTS is a module for the scaling constants for the compiled Fortran single and double precisions
SYNOPSIS¶
Variables¶
integer, parameter sp = kind(1.e0)
  
  real(sp), parameter szero = 0.0_sp
  
  real(sp), parameter shalf = 0.5_sp
  
  real(sp), parameter sone = 1.0_sp
  
  real(sp), parameter stwo = 2.0_sp
  
  real(sp), parameter sthree = 3.0_sp
  
  real(sp), parameter sfour = 4.0_sp
  
  real(sp), parameter seight = 8.0_sp
  
  real(sp), parameter sten = 10.0_sp
  
  complex(sp), parameter czero = ( 0.0_sp, 0.0_sp )
  
  complex(sp), parameter chalf = ( 0.5_sp, 0.0_sp )
  
  complex(sp), parameter cone = ( 1.0_sp, 0.0_sp )
  
  character *1, parameter sprefix = 'S'
  
  character *1, parameter cprefix = 'C'
  
  real(sp), parameter sulp = epsilon(0._sp)
  
  real(sp), parameter seps = sulp * 0.5_sp
  
  real(sp), parameter ssafmin = real(radix(0._sp), sp)**max(
    minexponent(0._sp)-1, 1-maxexponent(0._sp) )
  
  real(sp), parameter ssafmax = sone / ssafmin
  
  real(sp), parameter ssmlnum = ssafmin / sulp
  
  real(sp), parameter sbignum = ssafmax * sulp
  
  real(sp), parameter srtmin = sqrt(ssmlnum)
  
  real(sp), parameter srtmax = sqrt(sbignum)
  
  real(sp), parameter stsml = real(radix(0._sp), sp)**ceiling(
    (minexponent(0._sp) - 1) * 0.5_sp)
  
  real(sp), parameter stbig = real(radix(0._sp), sp)**floor(
    (maxexponent(0._sp) - digits(0._sp) + 1) * 0.5_sp)
  
  real(sp), parameter sssml = real(radix(0._sp), sp)**( - floor(
    (minexponent(0._sp) - digits(0._sp)) * 0.5_sp))
  
  real(sp), parameter ssbig = real(radix(0._sp), sp)**( - ceiling(
    (maxexponent(0._sp) + digits(0._sp) - 1) * 0.5_sp))
  
  integer, parameter dp = kind(1.d0)
  
  real(dp), parameter dzero = 0.0_dp
  
  real(dp), parameter dhalf = 0.5_dp
  
  real(dp), parameter done = 1.0_dp
  
  real(dp), parameter dtwo = 2.0_dp
  
  real(dp), parameter dthree = 3.0_dp
  
  real(dp), parameter dfour = 4.0_dp
  
  real(dp), parameter deight = 8.0_dp
  
  real(dp), parameter dten = 10.0_dp
  
  complex(dp), parameter zzero = ( 0.0_dp, 0.0_dp )
  
  complex(dp), parameter zhalf = ( 0.5_dp, 0.0_dp )
  
  complex(dp), parameter zone = ( 1.0_dp, 0.0_dp )
  
  character *1, parameter dprefix = 'D'
  
  character *1, parameter zprefix = 'Z'
  
  real(dp), parameter dulp = epsilon(0._dp)
  
  real(dp), parameter deps = dulp * 0.5_dp
  
  real(dp), parameter dsafmin = real(radix(0._dp), dp)**max(
    minexponent(0._dp)-1, 1-maxexponent(0._dp) )
  
  real(dp), parameter dsafmax = done / dsafmin
  
  real(dp), parameter dsmlnum = dsafmin / dulp
  
  real(dp), parameter dbignum = dsafmax * dulp
  
  real(dp), parameter drtmin = sqrt(dsmlnum)
  
  real(dp), parameter drtmax = sqrt(dbignum)
  
  real(dp), parameter dtsml = real(radix(0._dp), dp)**ceiling(
    (minexponent(0._dp) - 1) * 0.5_dp)
  
  real(dp), parameter dtbig = real(radix(0._dp), dp)**floor(
    (maxexponent(0._dp) - digits(0._dp) + 1) * 0.5_dp)
  
  real(dp), parameter dssml = real(radix(0._dp), dp)**( - floor(
    (minexponent(0._dp) - digits(0._dp)) * 0.5_dp))
  
  real(dp), parameter dsbig = real(radix(0._dp), dp)**( - ceiling(
    (maxexponent(0._dp) + digits(0._dp) - 1) * 0.5_dp))
  
  
Detailed Description¶
LA_CONSTANTS is a module for the scaling constants for the compiled Fortran single and double precisions
Author
Date
Contributors:
Further Details:
Anderson E. (2017)
Algorithm 978: Safe Scaling in the Level 1 BLAS
ACM Trans Math Softw 44:1--28
https://doi.org/10.1145/3061665
Blue, James L. (1978)
A Portable Fortran Program to Find the Euclidean Norm of a Vector
ACM Trans Math Softw 4:15--23
https://doi.org/10.1145/355769.355771
Author¶
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| Thu Aug 7 2025 17:26:25 | Version 3.12.0 |