constants_mod.f

75 lines · 1 definitions · on GitHub (7be4133)

Python version: constants_mod.py, 48 lines, on the right (switch to Python above the code).

Variables on this page (31)

c4pi, c4pi3l, c4pil, c_2, ca3, ca3l, cavog, cc13, cc23, cdelrl, cgas, cgl, cln, clndp, clni, clnsun, clsun, clsunl, cmbol, cmixl2, cmixl3, cmkh, cmkhn, cmsun, cmsunl, cpi, crsun, crsunl, csecyr, csig, csigl

Purpose

CONSTANTS_MOD holds the physical and mathematical constants (solar units, $\ln 10$, $\pi$, $G$, $\sigma$, the gas constant, and logarithms of them) shared by 89 routines. It replaces COMMON/CONST/, /CONST1/, /CONST2/ and /CONST3/ of rp_1, first merged into COMMON/CONSTANTS/ and then made a module (MHP via Claude, 10/14/26), without CMIXL (now passed as an argument) and with C_2 from COMMON/CWIND/. All members are REAL*8.

What its variables hold, who sets them, who reads them.

CAVOG: Avogadro's number, defined as the reciprocal of the atomic mass unit, $N_A = 1/(1.6605402\times10^{-24}\ \mathrm{g})$, the scale on which ENGEB gives its nuclear masses ANUC. The one PARAMETER (a fixed value, never set at run time); read by ENGEB and DEUTRATE in the deuterium-burning rate, where it replaces the hard-coded $6.023\times10^{23}$.
CLSUN, CRSUN: the solar luminosity and radius (cgs), with initial values 3.8515D33 and 6.9598D10 moved from PARMIN's DATA statement; both are in the PHYSICS namelist read by PARMIN, so a run can change them.
Set once in SETUPS (its comments name them): CLNDP and CLN ($\ln 10$), CLNI ($1/\ln 10$), CLSUNL, CMSUNL, CRSUNL (log of the solar luminosity, mass, radius), CLNSUN ($\ln 10/L_\odot$), CMSUN (1.9891D33 g), CMBOL (the Sun's bolometric magnitude, 4.79), CSECYR (seconds per year, 3.1558D7), CC13, CC23 (1/3, 2/3), CPI, C4PI, C4PIL ($\log 4\pi$), C4PI3L ($\log 4\pi/3$), CSIG and CSIGL (Stefan–Boltzmann), CA3 $=4\sigma/3c$ ($a/3$) and CA3L, CGAS (the gas constant), CGL ($\log G$), CMKH ($\log[(2\pi m_e)^{3/2}k^{5/2}/h^3]$, for the Saha equation), CDELRL $= -\log(4\pi/3) - \log\sigma - \log 16$ (the radiative gradient), CMIXL2 (1/3) and CMIXL3 $=16\sqrt2\,\sigma$ (mixing length).
CLN, CC13, CC23 are also set in PARMIN (to the same values, before SETUPS runs) and written in its DERIVED namelist to the .short file. C_2 (0.0506, the centrifugal term of the Matt et al. wind law) is set in PARMIN and read by MWIND and MCOWIND.
Readers: nearly every physics routine; CLN alone by 68 files, CGL by 34.
CMKHN is set and read nowhere (line 67 ↗; unused?); CA3L and CMSUNL are set (setups.f, line 162 ↗, setups.f, line 142 ↗) but never read (unused?).

Design

A blanket USE CONSTANTS_MOD in each routine. Apart from CAVOG, the constants are module variables set at run time rather than PARAMETERs, so a routine run before SETUPS would see them undefined.

Definitions

moduleCONSTANTS_MOD

lines 37–75 · GitHub

Used by (89 units)

(file level), AMCALC, CALCAD, CHKSCAL, CODIFF, COEFFT, COWIND, CRRECT, DBURNM, DEUTRATE, ENGEB, ENVINT, EQRELV, EQSAHA, EQSCVE, EQSCVG, EQSTAT, EQSTAT2, FPFT, FUNC, GETALEX06, GETFC, GETGRID, GETMODEL2, GETNEWENV, GETQUA, GETTAU, GETW, GETYREC7, GRSETT, HPOINT, HSUBP, HTIMER, INTMOM, LAX_WENDROF1, LAX_WENDROF2, LIBURN, LIBURN2, LIRATE88, MASSLOSS, MCOWIND, MDOT, MICRODIFF_COD, MICRODIFF_RUN, MICRODIFF_SETUP, MIDMOD, MIX, MIXGRID, MOMI, MU, MWIND, OEQOS06, OVERSH, PARMIN, PHYSIC, PUTMODEL2, PUTSTORE, PUTYREC7, QATM, QENV, RATES, REDUCE, ROTGRID, ROTMIX, RSCALE, SCONVEC, SECULR, SETSCAL, SETSCV, SETUPS, SETUPV, SETUP_GRSETT, SHAPE, STARIN, STITCH, SURFBC, TAUCAL, TAUINT, TAUINTNEW, TPGRAD, VCIRC, VISCOS, WCZIMP, WIND, WRTMIL, WRTMOD, WRTOUT, XTIME, YTIME

Change log

The changes since rp_1

Changed since rp_1. New file: COMMON/CONST/–/CONST3/ as one module, without CMIXL, with C_2 from /CWIND/, and the defaults of CLSUN, CRSUN moved from PARMIN.

Changed since 09c3b9b. New PARAMETER CAVOG (Avogadro's number as $1/m_u$), used by ENGEB and DEUTRATE for the deuterium-burning rate.

1C 2C 3C$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$ 4C CONSTANTS_MOD 5C$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$ 6C 10/14/26 MHP via Claude 7C code changed to convert COMMON/CONSTANTS/ into this module. 8C 9C Imported with a blanket USE, the convention for the conversion. 10C All 90 files declared this block identically, so the USE 11C imports exactly the names the declaration already made global in 12C each scoping unit and cannot change meaning. 13C 14C The types restate what the implicit rules supplied: L is 15C LOGICAL*4, I/J/K/M/N are INTEGER*4, everything else REAL*8. 16C SAVE is explicit rather than relying on module variables being 17C implicitly saved, which holds only from Fortran 2008 while ifort 18C Classic predates it. That matches COMMON's semantics. 19C CLSUN and CRSUN carry initializers, migrated from parmin.f's 20C DATA CLSUN,CRSUN/3.8515D33,6.9598D10/ 21C because DATA on a USE-associated name is rejected. Both are PHYSICS 22C namelist variables, so the DATA statement supplied a default the 23C namelist read could override; a module initializer is applied once at 24C load time, before PARMIN runs, which is the same thing. The derived 25C CLSUNL and CRSUNL are set later still, in setups.f, so the order 26C initializer -> namelist read -> derivation is unchanged. 27C 28C The other 28 members have no initializer because none had DATA: they 29C are set by executable assignment in parmin.f and setups.f, which needs 30C no change under USE association. 31C 10/27/26 MHP via Claude 32C code changed to add CAVOG, Avogadro's number, defined as the 33C reciprocal of the atomic mass unit 1.6605402D-24 g (the scale ANUC 34C is expressed on in engeb.f). It replaces the hardcoded 6.023D23 in 35C the deuterium burning rates of engeb.f and deutrate.f. A PARAMETER, 36C since unlike the members below it is never set at run time. 37 MODULE CONSTANTS_MOD 38 39 IMPLICIT NONE 40 SAVE 41 42 REAL*8, PARAMETER :: CAVOG = 1.0D0/1.6605402D-24 43 44 REAL*8 :: CLSUN = 3.8515D33 45 REAL*8 :: CLSUNL 46 REAL*8 :: CLNSUN 47 REAL*8 :: CMSUN 48 REAL*8 :: CMSUNL 49 REAL*8 :: CRSUN = 6.9598D10 50 REAL*8 :: CRSUNL 51 REAL*8 :: CMBOL 52 REAL*8 :: CLN 53 REAL*8 :: CLNI 54 REAL*8 :: C4PI 55 REAL*8 :: C4PIL 56 REAL*8 :: C4PI3L 57 REAL*8 :: CC13 58 REAL*8 :: CC23 59 REAL*8 :: CPI 60 REAL*8 :: CGAS 61 REAL*8 :: CA3 62 REAL*8 :: CA3L 63 REAL*8 :: CSIG 64 REAL*8 :: CSIGL 65 REAL*8 :: CGL 66 REAL*8 :: CMKH 67 REAL*8 :: CMKHN 68 REAL*8 :: CDELRL 69 REAL*8 :: CMIXL2 70 REAL*8 :: CMIXL3 71 REAL*8 :: CLNDP 72 REAL*8 :: CSECYR 73 REAL*8 :: C_2 74 75 END MODULE CONSTANTS_MOD

1"""Python version of constants_mod.f (YREC 7be4133): the physical and 2mathematical constants, formerly COMMON/CONST/, /CONST1/, /CONST2/, 3/CONST3/ and C_2 of /CWIND/. 4 5Translates: constants_mod.f#CONSTANTS_MOD (7be4133) 6 7Module-level names, as in the Fortran module, in lower case (all REAL*8). 8Routines that USE CONSTANTS_MOD import this module and write 9``constants_mod.<name>``. Apart from cavog, clsun and crsun, the values 10are set at run time by setups (and cln, cc13, cc23, c_2 by parmin). 11""" 12 13# Avogadro's number as the reciprocal of the atomic mass unit in g (the 14# scale of ENGEB's nuclear masses ANUC); a PARAMETER in the Fortran 15# (Fortran line 42). 16cavog = 1.0 / 1.6605402e-24 17 18# The members set at run time, or by the namelist (Fortran lines 44–73). 19clsun = 3.8515e33 # solar luminosity (initializer; PHYSICS namelist) 20clsunl = 0.0 # log10(clsun) (setups) 21clnsun = 0.0 # ln(10)/clsun (setups) 22cmsun = 0.0 # solar mass, 1.9891e33 g (setups) 23cmsunl = 0.0 # log10(cmsun) (setups; read nowhere: unused?) 24crsun = 6.9598e10 # solar radius (initializer; PHYSICS namelist) 25crsunl = 0.0 # log10(crsun) (setups) 26cmbol = 0.0 # solar bolometric magnitude, 4.79 (setups) 27cln = 0.0 # ln(10) (parmin, setups) 28clni = 0.0 # 1/ln(10) (setups) 29c4pi = 0.0 # 4 pi (setups) 30c4pil = 0.0 # log10(4 pi) 31c4pi3l = 0.0 # log10(4 pi / 3) 32cc13 = 0.0 # 1/3 (parmin, setups) 33cc23 = 0.0 # 2/3 (parmin, setups) 34cpi = 0.0 # pi (setups) 35cgas = 0.0 # gas constant (setups) 36ca3 = 0.0 # 4 sigma / (3 c) (setups) 37ca3l = 0.0 # log10(ca3) (setups; read nowhere: unused?) 38csig = 0.0 # Stefan-Boltzmann constant (setups) 39csigl = 0.0 # log10(csig) 40cgl = 0.0 # log10(G) (setups) 41cmkh = 0.0 # Saha constant (setups) 42cmkhn = 0.0 # set and read nowhere (unused?) 43cdelrl = 0.0 # constant of the radiative gradient (setups) 44cmixl2 = 0.0 # 1/3 (setups) 45cmixl3 = 0.0 # 16 sqrt(2) sigma (setups) 46clndp = 0.0 # ln(10) (setups) 47csecyr = 0.0 # seconds per year, 3.1558e7 (setups) 48c_2 = 0.0 # centrifugal factor of the wind law, 0.0506 (parmin)