EOSHIFT(3I) Last changed: 1-6-98
NAME
EOSHIFT - Performs an end-off shift on an array expression
SYNOPSIS
EOSHIFT ([ARRAY=]array, [SHIFT=]shift [,[BOUNDARY=]boundary]
[,[DIM=]dim])
IMPLEMENTATION
UNICOS, UNICOS/mk, and IRIX systems
STANDARDS
Fortran 90
DESCRIPTION
The EOSHIFT intrinsic function performs an end-off shift on an array
expression of rank one, or it performs end-off shifts on all the
complete rank one sections along a given array expression of rank two
or greater. Elements are shifted off at one end of a section and
copies of a boundary value are shifted in at the other end. Different
sections can have different boundary values and can be shifted by
different amounts and in different directions; positive for left
shifts, negative for right shifts.
EOSHIFT accepts the following arguments:
array May be of any type. It must not be scalar.
shift Must be integer. If array has rank one, shift must be a
scalar. Otherwise, shift must be scalar or have rank n-1
and have
shape (d , d , ..., d , d , ..., d ),
1 2 dim-1 dim+1 n
where (d , d , ..., d )
1 2 n
is the shape of array.
boundary Must be of the same type and have the same type parameters
as array. Must be scalar if array has rank one; otherwise,
it must be either scalar or of rank n-1 and of
shape (d , d , ..., d , d , ..., d ),
1 2 dim-1 dim+1 n
The boundary argument can be omitted for the data types in
the following list. In these cases, the default value is
the scalar value shown:
Type of array Default Value of boundary
Integer 0
Real 0.0
Complex (0.0,0.0)
Logical false
Character(len) len blanks
The boundary data type must be present for derived data
types.
dim Must be a scalar. Must be an integer value in the range
1 <= dim <= n, where n is the rank of array. If dim is
omitted, the default value is 1.
EOSHIFT is a transformational intrinsic function. The name of this
intrinsic cannot be passed as an argument.
RETURN VALUES
The result is an array of the same type, type parameters, and shape as
array.
Element (s , s , ..., s )
1 2 n
of the result has the value
array(s , s , ..., s , s + sh, s , ..., s ),
1 2 dim-1 dim dim+1 n
where sh is shift or
shift(s , s , ..., s , s , ..., s ),
1 2 dim-1 dim+1 n
provided that the inequality
LBOUND(array,dim) <= s + sh <= UBOUND(array,dim)
dim
holds and is otherwise boundary or
boundary(s , s , ..., s , s , ..., s ).
1 2 dim-1 dim+1 n
EXAMPLES
Example 1: If V is an array [1, 2, 3, 4, 5, 6], the effect of
shifting V end-off to the left by three positions is achieved by
EOSHIFT(V, SHIFT = 3), which has the value [4, 5, 6, 0, 0, 0].
Specifying EOSHIFT(V, SHIFT = -2, BOUNDARY = 99) achieves an end-off
shift to the right by two positions with the boundary value of 99 and
has the value of [99, 99, 1, 2, 3, 4].
Example 2: The rows of an array of rank two can all be shifted by the
same amount or by different amounts and the boundary elements can be
the same or different. Assume that M is the following array:
| A B C |
| D E F |
| G H I |
The value of EOSHIFT(M, SHIFT =-1, BOUNDARY = '*', DIM = 2) is as
follows:
| * A B |
| * D E |
| * G H |
The value of EOSHIFT(M, SHIFT =(/ -1, 1, 0 /), BOUNDARY = (/ '*', '/',
'?' /), DIM = 2) is as follows:
| * A B |
| E F / |
| G H I |
The value of section EOSHIFT(M(2:3,2:3), SHIFT = -1, BOUNDARY = '*',
DIM=2) is as follows:
| * E |
| * H |
SEE ALSO
Intrinsic Procedures Reference Manual, publication SR-2138, for the
printed version of this man page.
