Mapping Toolbox

sizem

Determine row and column dimensions needed for a regular matrix map

Syntax

• [r,c] = sizem(latlim,lonlim,scale)
  rc = sizem(latlim,lonlim,scale)
  [r,c,maplegend] = sizem(latlim,lonlim,scale)
  

Description

[r,c] = sizem(latlim,lonlim,scale) returns the required size for a regular matrix map lying between the latitude and longitude limits specified by the two-element input vectors latlim and lonlim, which are of the form [south-limit north-limit] and [west-limit and east-limit], respectively. The scale is the desired "cells-per-degree" measure of the desired matrix map.

rc = sizem(latlim,lonlim,scale) returns the size of the matrix in one two-element vector.

[r,c,maplegend] = sizem(latlim,lonlim,scale) also returns the map legend vector for the desired regular matrix map.

Examples

How large a matrix would be required for a map of the world at a scale of 25 matrix cells per degree? (That's 25x25=625 cells per "square" degree.)

• [r,c] = sizem([90,-90],[-180,180],25)
  r =
          4500
  c =
          9000
  

Bear in mind for memory purposes - 9000x4500=4.05x10⁷ entries!

See Also

findm	Coordinates of nonzero map entries
limitm	Matrix map limits
map legend vector	Data structure for describing regular matrix maps
nanm onem spzerom zerom	Create special maps

    

showm

sm2deg, sm2km, sm2nm, sm2rad