Mapping Toolbox

maskm

Replace entries of a matrix map specified by a mask matrix

Syntax

• mapout = maskm(map,mask)
  mapout = maskm(map,mask,newcode)
  

Description

mapout = maskm(map,mask,newcode) returns a matrix map mapout identical to the matrix map, map, except that every element corresponding to a 1 in mask is replaced with the scalar value newcode. mask is a matrix of 1s and 0s, the same size as map. The mask can be the result of a logical operation on the variable map (e.g., mask = (map>100)). When no newcode is supplied, NaNs are inserted.

Examples

Invent a map:

• map = magic(3)
  map =
       8     1     6
       3     5     7
       4     9     2
  

Use a logical test on the map as a mask. Replace with the default value (NaN):

• mapout = maskm(map,(map>5))
  mapout =
     NaN     1   NaN
       3     5   NaN
       4   NaN     2
  

See Also

changem

Replace certain values in a matrix map

maptrims

mat2dms