pm_mathExp::isIntPow Interface Reference

Generate and return .true. if and only if the input positive integer is a whole-number (integer) power of the specified integer base. More...

Detailed Description

Generate and return .true. if and only if the input positive integer is a whole-number (integer) power of the specified integer base.

The procedures of this generic interface rely on the binary representation of numbers to determine if the number is a power of base two.
For all other cases, an iterative division approach is used to determine the output.

Parameters

[in]	absx	: The input scalar (or array of the same rank, shape, and size as other array-like arguments) of, type integer of kind any supported by the processor (e.g., IK, IK8, IK16, IK32, or IK64), representing the absolute value of the number for which the next integer exponent in specified base must be computed.
[in]	base	: The input positive scalar (or array of the same rank, shape, and size as other array-like arguments), of the same type and kind as absx, representing the base of the exponentiation. (optional, default = 2)

Returns

powisint : The output scalar (or array of the same rank, shape, and size as other array-like arguments), of the type logical of default kind LK that is .true. if and only if the input absx is an integer power of the input absx.

Possible calling interfaces ⛓

use pm_mathExp, only: isIntPow
logical(LK) :: powisint
 
powisint = isIntPow(absx)
powisint = isIntPow(absx, base)

Warning

The condition 0 < absx must hold.
The condition 1 <= base must hold.
These conditions are verified only if the library is built with the preprocessor macro CHECK_ENABLED=1.

The pure procedure(s) documented herein become impure when the ParaMonte library is compiled with preprocessor macro CHECK_ENABLED=1.
By default, these procedures are pure in release build and impure in debug and testing builds.

Remarks

The procedures under discussion are elemental.

See also

isIntPow
getExpNext
getExpPrev

Example usage ⛓

program example
 
    use pm_kind, only: SK, IK, LK
    use pm_mathExp, only: isIntPow
    use pm_io, only: display_type
 
    implicit none
 
    integer(IK), allocatable :: expNext(:)
 
    type(display_type) :: disp
    disp = display_type(file = "main.out.F90")
 
    allocate(expNext(1))
 
    call disp%skip()
    call disp%show("isIntPow(1)")
    call disp%show( isIntPow(1) )
    call disp%show("isIntPow(abs([1, -2, 3, -4, 5, 9, 519]))")
    call disp%show( isIntPow(abs([1, -2, 3, -4, 5, 9, 519])) )
    call disp%show("isIntPow(abs([1, -2, 3, -4, 5, 9, 519]), base = 3)")
    call disp%show( isIntPow(abs([1, -2, 3, -4, 5, 9, 519]), base = 3) )
    call disp%skip()
 
end program example

Example Unix compile command via Intel ifort compiler ⛓

#!/usr/bin/env sh
rm main.exe
ifort -fpp -standard-semantics -O3 -Wl,-rpath,../../../lib -I../../../inc main.F90 ../../../lib/libparamonte* -o main.exe
./main.exe

Example Windows Batch compile command via Intel ifort compiler ⛓

del main.exe
set PATH=..\..\..\lib;%PATH%
ifort /fpp /standard-semantics /O3 /I:..\..\..\include main.F90 ..\..\..\lib\libparamonte*.lib /exe:main.exe
main.exe

Example Unix / MinGW compile command via GNU gfortran compiler ⛓

#!/usr/bin/env sh
rm main.exe
gfortran -cpp -ffree-line-length-none -O3 -Wl,-rpath,../../../lib -I../../../inc main.F90 ../../../lib/libparamonte* -o main.exe
./main.exe

Example output ⛓

 
isIntPow(1)
T
isIntPow(abs([1, -2, 3, -4, 5, 9, 519]))
T, T, F, T, F, F, F
isIntPow(abs([1, -2, 3, -4, 5, 9, 519]), base = 3)
F, F, T, F, F, T, F
 
 

Test:

test_pm_mathExp

Final Remarks ⛓

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For details on the naming abbreviations, see this page.
For details on the naming conventions, see this page.
This software is distributed under the MIT license with additional terms outlined below.

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Help us justify its continued development and maintenance by acknowledging its benefit to society, distributing it, and contributing to it.

Copyright

Computational Data Science Lab

Author:

Amir Shahmoradi, April 25, 2015, 2:21 PM, National Institute for Fusion Studies, The University of Texas Austin

Definition at line 113 of file pm_mathExp.F90.

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The documentation for this interface was generated from the following file:

• src/fortran/main/pm_mathExp.F90