What is the role of the referencing matrix/vector when passed as an input to CONTOURM in the Mapping Toolbox 2.7.1 (R2008b)?

The documentation for CONTOURM mentions that "contourm(Z,R) creates a contour plot of the regular M-by-N data grid, Z. R is a referencing matrix or referencing vector".

I would like to know the role of R and why I need to pass this to CONTOURM.

Answer 1

[MathWorks Support Team]

This change has been incorporated into the documentation in Release 2009b (R2009b). For previous releases, read below for any additional information:

The referencing matrix or vector is required to describe the scaling, orientation, and placement of the data grid on the globe. For a given referencing matrix, R, one of the following relations holds between rows and columns and coordinates (depending on whether the grid is based on map coordinates or geographic coordinates, respectively):

[x y] = [row col 1] * R, or

[long lat] = [row col 1] * R

More information about the role of the referencing matrix or vector is available under the "Understanding Raster Geodata" section in the Mapping Toolbox documentation:

 <http://www.mathworks.com/access/helpdesk/help/toolbox/map/f20-18717.html>