Why do I receive "Inf" when I use the PROJINV function to determine latitude/longitude in the Mapping Toolbox 1.3 (R13SP1)?

Why do I receive "Inf" when I use the PROJINV function to determine latitude/longitude in the Mapping Toolbox 1.3 (R13SP1)?

When I use the PROJINV function to determine the latitude and longitude of a particular location, I receive "Inf".

Answer 1

[MathWorks Support Team]

In order to use the PROJINV function, the geoid field must be filled in. It is this structure which determines the surface type of the geoid, and the units which are used.

The following code can serve as an example to show the correct initialization of the "mstruct" and its use within PROJINV:

al = defaultm('eqaconic');

al.geoid = almanac('earth','sphere','m');

al.falsenorthing = -4e6;

al.mapparallels = [34 40.5];

al.origin = [0 -120 0];

[lat,long] = projinv( al, 4.5e4, 2.5e5)