Problem with horizon factor in orthographic and stereographic plots
|Target version:||Candidate for next bugfix release|
I'm trying to implement a very simple "zoom" feature by utilizing the horizon parameter of the orthographic projection (documentation excerpt below):
horizon specifies the max distance from projection center (in degrees, ⇐ 90, default 90).
Using the version 5.1.2 GMT interface, I made 2 plots with the following psbasemap parameters:
1) psbasemap -R-180/180/0/90 -JG0.000000/90.000000/90.000000/6.0i ...
2) psbasemap -R-180/180/0/90 -JG0.000000/90.000000/9.000000/6.0i ...
I had expected plot 2) to be a magnified version of plot 1) since the horizon parameter is set 10x smaller. However, the plots came out identical. This is the case with the stereographic projection as well (-JS).
However, when I used this same technique with the gnomonic projection (-JF) it produced a magnified plot as I had expected!
#1 Updated by Paul about 5 years ago
- Status changed from New to In Progress
Leaving on vacation and cannot easily follow up but: The only projection that is not from infinity is the General Perspective (-JG with a bunch of arguments; see docs). Going -JG and a size means the plot will b that size regardless of -R etc. Gnomonic is different since it actually projects from the center of the globe.