Help Articles are product support tips and information straight from the NV5 Geospatial Technical Support team developed to help you use our products to their fullest potential.

With IDL Object Graphics, plotting two graphics with different data extents in the same graphic window requires normalizing the range of the second graphic to fit the extension of the first one. If not, the two graphics will not fit within the same view.

IDL includes a routine called FILLPLOT which allows to create horizontal filled plots. However it does not support vertical filled plots:

https://www.nv5geospatialsoftware.com/docs/FILLPLOT.html

The easiest way to build vertical filled plots is then to use the POLYGON routine instead:

https://www.nv5geospatialsoftware.com/docs/POLYGON.html

QHULL is an IDL routine to apply Quick Hull algorithm for various applications.

Bibliography: “The Quickhull Algorithm for Convex Hulls,” ACM Transactions on Mathematical Software, Vol. 22, No 4, December 1996, Pages 469-483, Barber, Dobkin and Huhdanpaa

One application consists in building the largest convex polygon around a set of random points. The example below is showing how to use QHULL in such context.