spatial reference transformation issue with the new cross-section plot class

[flydream0428]

The new cross-section class doesn't do spatial transformation even when the spatial reference information has been configured through DIS and modelgrid class.
For example, let's say I have loaded a model mf, then I configure the spatial reference,

mf.modelgrid.set_coord_info(xoff=xoff, yoff=yoff, angrot=0)

Then, I do the plot,
flopy.plot.PlotCrossSection(model=mf, line=line={'Row': 10})

The cross-section plot still starts from 0 rather than xoff.

[jlarsen-usgs]

@flydream0428, I'll take a look at this issue.

[jlarsen-usgs]

The issue in the plotting code. Currently the plotting code is translating the modelgrid to model coordinates (i.e. xoffset=0, yoffset=0, and angrot=0). I'm working on a patch for this and will submit a PR to translate the cross sections back to geographic coordinates.

[jlarsen-usgs]

@flydream0428, I've added a new feature to the PlotCrossSection class that allows the user to plot in geographic coordinates. The default behavior was, and still is, to plot cross sections with the cross sectional distance on the x-axis. This behavior is useful for arbitrary cross sections, because the code does not have to choose a projection direction to display the data from.

To plot using geographic coordinates you can use

pxc = PlotCrossSection(model=mf, line={"column": 10}, geographic_coords=True)

Examples can be found in the flopy3_PlotCrossSection_demo.ipynb