create gsplot class

[jordansread]

decision to make S3 or S4, then implement.

Advantage of S3 is more flexibility (and sloppiness), easier debugging, faster coding. Can do
points.gsplot(x,y,...) to create the method for points(gsplot,x,y,...)

Advantage of S4 is more explicit code and rigidity in structure, and supports multiple arg dispatch.

[jordansread]

here is an example of S4: https://github.com/USGS-R/geoknife/blob/master/R/02-webgeom-obj.R
here is an example of S3: https://github.com/USGS-R/glmtools/blob/master/R/nml.R

[jordansread]

For completeness, R6 looks pretty sweet http://cran.r-project.org/web/packages/R6/vignettes/Introduction.html

[jordansread]

my vote is S3

[ldecicco-USGS]

S3

[ldecicco-USGS]

Now the issue is to implement the gsplot S3 class.

[jiwalker-usgs]

Calling this good, may need to make minor tweaks as things come up.