shift,shift0

shift, shift0

Shifts the value of each cell a specified number of cells in the assigned direction.

Result = shift(expression, northing, westing)

Result = shift0(expression, northing, westing)

expression

boolean, nominal, ordinal, scalar, directional, ldd, spatial

northing

scalar, non-spatial

westing

scalar, non-spatial

Result

datatype of expression, spatial

Operation

Each cell of expression is shifted a number of cells equal to the value of northing to the north (up) if northing is positive, or to the south (down) if northing is negative and each cell of expression is shifted a number of cells equal to the value of westing to the west (left) if westing is positive, or to the east (right) if westing is negative. The values of northing and southing are rounded down to the nearest integer. The shift and shift0 operation will result in a number equal to the value of northing of rows being lost on the north side of the map and created on the south side of the map. Similarly a number of columns equal to the value of westing will be lost on the west side of the map and created on the east side of the map. The newly created rows or columns will have missing values when using shift and will be assigned 0 when using shift0.

Notes

When using shift0 missing values that already exist in expression will also be assigned 0.

Examples

1. • pcrcalc

   binding

   Result = Result.map;

   Expr = Expr.map;

   initial

   report Result = shift(Expr, 1,1);

   
   

   • python

   Expr = readmap(“Expr.map”)

   Result = shift(Expr, 1,1)

   Result.map	Expr.map

   
   
2. • pcrcalc

   binding

   Result2 = Result2.map;

   Expr = Expr.map;

   initial

   report Result2 = shift(Expr, -1,-1);

   
   

   • python

   Expr = readmap(“Expr.map”)

   Result2 = shift(Expr, -1,-1)

   Result2.map	Expr.map

   
   
3. • pcrcalc

   binding

   Result1 = Result1.map;

   Expr = Expr.map;

   initial

   report Result1 = shift0(Expr, -1,-1);

   
   

   • python

   Expr = readmap(“Expr.map”)

   Result1 = shift0(Expr, -1,-1)

   Result1.map	Expr.map