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