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mod

Remainder function which emulates the fortran "mod" intrinsic function.

Available in version 4.3.0 or later.

Prototype

load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/contributed.ncl"

	function mod (
		n  : numeric,  ; integer, float, double
		m  : numeric   
	)

	return_val  :  same type and shape as n

Arguments

n

Scalar or array variable of type integer, float, double.

m

Scalar or array variable. If an array it must be the same shape as n. Although not required, it is best if it is the same type as n.

Description

NCL has a modulus algebraic operator, % , which requires that the arguments be integers. The mod function is more general. The results are the same as those of the the GNU "gfortran" compiler. While the function allows mixed types, it is best to always use n and m of the same type.

Examples

The contributed.ncl library must be loaded prior to invoking the function:

load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/contributed.ncl"

Sample usage: numeric results and return types. Note that the returned value is the same numeric type and sign as argument n.

        mod(17,3)         = 2     type= integer

        mod(17.5,5.5)     = 1     type= float
        mod(17.5d0,5.5)   = 1     type= double
        mod(17.5d0,5.5d0) = 1     type= double
        mod(17.5,5.5d0)   = 1     type= float
             
        mod(17.5, 5 )     = 2.5   type= float
        mod(17  ,5.5)     = 2     type= integer
                
        mod(-17,3)        = -2    type= integer
        mod(-17.5,5.5)    = -1    type= float
        mod(-17.5d0,5.5)  = -1    type= double
        mod(-17.5d0,5.5d0)= -1    type= double
        mod(-17.5,5.5d0)  = -1    type= float
                
        mod(-17.5, 5 )    = -2.5  type= float
        mod(-17  ,5.5)    = -2    type= integer
                
        mod(17,-3)        = 2     type= integer
        mod(17.5,-5.5)    = 1     type= float
        mod(17.5d0,-5.5)  = 1     type= double
        mod(17.5d0,-5.5d0)= 1     type= double
        mod(17.5,-5.5d0)  = 1     type= float
                
        mod(17.5, -5 )    = 2.5   type= float
        mod(17  ,-5.5)    = 2     type= integer