MODULE Numeric_Kinds_Module
!=========================================================================================
! This module defines types and constants to be used throughout other codes. Here is 
! defined the real type wp_kind (working precision) that defines the real type of all
! declared real variables. 
!
! D. A. Brue
!=========================================================================================
IMPLICIT NONE

! Define compiler-dependent type constants as parameters
INTEGER, PARAMETER :: i1_kind = SELECTED_INT_KIND(2)  ! -128, 127
INTEGER, PARAMETER :: i2_kind = SELECTED_INT_KIND(4)  ! 
INTEGER, PARAMETER :: i4_kind = SELECTED_INT_KIND(9)
INTEGER, PARAMETER :: i8_kind = SELECTED_INT_KIND(12)

INTEGER, PARAMETER :: sp_kind = SELECTED_REAL_KIND(p=6,r=30)    ! single precision
INTEGER, PARAMETER :: dp_kind = SELECTED_REAL_KIND(p=14,r=300)  ! double precision
INTEGER, PARAMETER :: qp_kind = SELECTED_REAL_KIND(p=30,r=4000) ! quadruple precision
! note above real kind types also work for complex declarations

! Select real kind to be used throughout the rest of code
INTEGER, PARAMETER :: WP_Kind = dp_kind
INTEGER, PARAMETER :: IW_Kind = i4_kind

! Numbers  ===============================================================================
INTEGER, PARAMETER :: ione      = 1
INTEGER, PARAMETER :: itwo      = 2
INTEGER, PARAMETER :: ithree    = 3
INTEGER, PARAMETER :: ifour     = 4
REAL(Kind=WP_Kind), PARAMETER :: zero   =  0.0_wp_kind
REAL(Kind=WP_Kind), PARAMETER :: one    =  1.0_wp_kind
REAL(Kind=WP_Kind), PARAMETER :: two    =  2.0_wp_kind
REAL(Kind=WP_Kind), PARAMETER :: three  =  3.0_wp_kind
REAL(Kind=WP_Kind), PARAMETER :: four   =  4.0_wp_kind
REAL(Kind=WP_Kind), PARAMETER :: five   =  5.0_wp_kind
REAL(Kind=WP_Kind), PARAMETER :: six    =  6.0_wp_kind
REAL(Kind=WP_Kind), PARAMETER :: seven  =  7.0_wp_kind
REAL(Kind=WP_Kind), PARAMETER :: eight  =  8.0_wp_kind
REAL(Kind=WP_Kind), PARAMETER :: nine   =  9.0_wp_kind
REAL(Kind=WP_Kind), PARAMETER :: ten    = 10.0_wp_kind
REAL(Kind=WP_Kind), PARAMETER :: eleven = 11.0_wp_kind
REAL(Kind=WP_Kind), PARAMETER :: twelve = 12.0_wp_kind
REAL(Kind=WP_Kind), PARAMETER :: thirteen = 13.0_wp_kind
REAL(Kind=WP_Kind), PARAMETER :: fourteen = 14.0_wp_kind
REAL(Kind=WP_Kind), PARAMETER :: fifteen  = 15.0_wp_kind

! Fractions
REAL(Kind=WP_Kind), PARAMETER :: half   = 0.50_wp_kind

! Common Reals
REAL(Kind=WP_Kind), PARAMETER :: pi=four*ATAN(one)

! Numerics ===============================================================================
REAL(Kind=WP_Kind), PARAMETER :: wp_Small  = TINY(one)  ! smallest number
REAL(Kind=WP_Kind), PARAMETER :: wp_Large  = HUGE(one)  ! largest number
REAL(Kind=WP_Kind), PARAMETER :: wp_Epsilon= EPSILON(one) ! smallest difference
INTEGER, PARAMETER :: wp_Prec   = PRECISION(one)    ! number of digits of precision
INTEGER, PARAMETER :: wp_minexp = MINEXPONENT(one)  ! smallest exponent
INTEGER, PARAMETER :: wp_maxexp = MAXEXPONENT(one)  ! largest exponent

END MODULE Numeric_Kinds_Module