eoshift(3I)

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, IRIX systems

     CF90, MIPSpro 7 Fortran 90

STANDARDS
     Fortran

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 for the printed version of this
     man page.