Manual Reference Pages - nint (3fortran)
NAME
NINT(3) - [TYPE:NUMERIC] Nearest whole number
SYNOPSIS
result = nint( a [,kind] )
elemental integer(kind=KIND) function nint(a, kind )real(kind=**),intent(in) :: a integer(kind=**),intent(in),optional :: KIND
CHARACTERISTICS
o a kind designated as ** may be any supported kind for the type o A is type real of any kind o KIND is a scalar integer constant expression o The result is default integer kind or the value of KIND if KIND is present.
DESCRIPTION
NINT(3) rounds its argument to the nearest whole number with its sign preserved.
The user must ensure the value is a valid value for the range of the KIND returned. If the processor cannot represent the result in the kind specified, the result is undefined.
If A is greater than zero, NINT(A) has the value INT(A+0.5).
If A is less than or equal to zero, NINT(A) has the value INT(A-0.5).
OPTIONS
o A : The value to round to the nearest whole number o KIND : can specify the kind of the output value. If not present, the output is the default type of integer.
RESULT
The result is the integer nearest A, or if there are two integers equally near A, the result is whichever such integer has the greater magnitude.
The result is undefined if it cannot be represented in the specified integer type.
EXAMPLES
Sample program:
program demo_nint implicit none integer,parameter :: dp=kind(0.0d0) real,allocatable :: in(:) integer,allocatable :: out(:) integer :: i real :: x4 real(kind=dp) :: x8Results:! basic use x4 = 1.234E0 x8 = 4.721_dp print *, nint(x4), nint(-x4) print *, nint(x8), nint(-x8)
! elemental in = [ -2.7, -2.5, -2.2, -2.0, -1.5, -1.0, -0.5, -0.4, & & 0.0, & & +0.04, +0.5, +1.0, +1.5, +2.0, +2.2, +2.5, +2.7 ] out = nint(in) do i=1,size(in) write(*,*)in(i),out(i) enddo
! dusty corners ISSUES: block use,intrinsic :: iso_fortran_env, only : int8, int16, int32, int64 integer :: icheck ! make sure input is in range for the type returned write(*,*)’Range limits for typical KINDS:’ write(*,’(1x,g0,1x,g0)’) & & int8,huge(0_int8), & & int16,huge(0_int16), & & int32,huge(0_int32), & & int64,huge(0_int64)
! the standard does not require this to be an error ... x8=12345.67e15 ! too big of a number icheck=selected_int_kind(ceiling(log10(x8))) write(*,*)’Any KIND big enough? ICHECK=’,icheck print *, ’These are all wrong answers for ’,x8 print *, nint(x8,kind=int8) print *, nint(x8,kind=int16) print *, nint(x8,kind=int32) print *, nint(x8,kind=int64) endblock ISSUES
end program demo_nint
> 1 -1 > 5 -5 > -2.700000 -3 > -2.500000 -3 > -2.200000 -2 > -2.000000 -2 > -1.500000 -2 > -1.000000 -1 > -0.5000000 -1 > -0.4000000 0 > 0.0000000E+00 0 > 3.9999999E-02 0 > 0.5000000 1 > 1.000000 1 > 1.500000 2 > 2.000000 2 > 2.200000 2 > 2.500000 3 > 2.700000 3 > Range limits for typical KINDS: > 1 127 > 2 32767 > 4 2147483647 > 8 9223372036854775807 > Any KIND big enough? ICHECK= -1 > These are all wrong answers for 1.234566949990144E+019 > 0 > 0 > -2147483648 > -9223372036854775808
STANDARD
FORTRAN 77 , with KIND argument - Fortran 90
SEE ALSO
AINT(3), ANINT(3), INT(3), SELECTED_INT_KIND(3), CEILING(3), FLOOR(3)
fortran-lang intrinsic descriptions (license: MIT) @urbanjost
| Nemo Release 3.1 | nint (3fortran) | April 28, 2024 |
