Module Math_Constants_Module
! This file:
! http://ftp.aset.psu.edu/pub/ger/fortran/hdk/MathConstnts.f95
!
! by J.E. Akin: http://www.owlnet.rice.edu/~mech517/Books/oop2.pdf.
! Also see Table of Constants to 50 Places at:
! http://numbers.computation.free.fr/Constants/Miscellaneous/digits.html
! Special thanks to Howard W. Ludwig.
Implicit none
 integer, public, parameter :: DP = selected_real_kind(15)

 real(kind=DP), public, parameter::              &
 Deg_Per_Rad  = 57.2957795130823208767981548_DP, &
 Rad_Per_Deg  = 0.01745329251994329576923691_DP, &

 e_Value      =  2.7182818284590452353602287_DP, &
 e_Recip      =  0.3678794411714423215955238_DP, &
 e_Squared    =  7.3890560989306502272304275_DP, &
 Log10_of_e   =  0.4342944819032518276511289_DP, &

 Euler        =  0.5772156649015328606065121_DP, &
 Euler_Log    = -0.5495393129816448223376617_DP, &
 Gamma        =  0.5772156649015328606065121_DP, &
 Gamma_Log    = -0.5495393129816448223376617_DP, &
 Golden_Ratio =  1.6180339887498948482045868_DP, &

 Ln_2         =  0.6931471805599453094172321_DP, &
 Ln_10        =  2.3025850929940456840179915_DP, &
 Log10_of_2   =  0.3010299956639811952137389_DP, &

 pi_Value     =  3.1415926535897932384626434_DP, &
 pi_Ln        =  1.1447298858494001741434273_DP, &
 pi_Log10     =  0.4971498726941338543512683_DP, &
 pi_Over_2    =  1.5707963267948966192313217_DP, &
 pi_Over_3    =  1.0471975511965977461542145_DP, &
 pi_Over_4    =  0.7853981633974483096156608_DP, &
 pi_Recip     =  0.3183098861837906715377675_DP, &
 pi_Squared   =  9.8696044010893586188344910_DP, &
 pi_Sq_Root   =  1.7724538509055160272981675_DP, &

 Sq_Root_of_2 =  1.4142135623730950488016887_DP, &
 Sq_Root_of_3 =  1.7320508075688772935274463_DP

End Module Math_Constants_Module

program print_pi

use math_constants_module

print *, pi_Value

end program print_pi