Is geodesic rectangular possible for a option of "m.set_shape." ?

[yun881201]

Hello again.
Thank you very much for your work developing EOmaps. I wish for the prosperity of EOmaps.

I have a question for the options of "m.set_shape.". Currently, "m.set_shape." has no option for geodesic rectangular. Is geodesic rectangular possible for a option of "m.set_shape." ?

In my field, unit of collecting data is a 1km or 2km rectangular region of the country. So I have data of which columns are (lon, lat) of the rectangular center and measurement value on the rectangular. Currently, I can only rely on "m.set_shape.geod_circles(radius)". This gives me a enough good visualization, but there is a regret that I want it to be a rectangle.

[raphaelquast]

Hey,
thanks I wish for its prosperity too... make sure to spread the word 😄!

At the moment there is no option for "geodesic rectangles"... (If I find the time I might implement it someday... feel free to come up with a pull-request if you feel up to the task!)

However, the good thing is that EOmaps already provides a means of drawing rectangles whose dimensions can be defined in arbitrary projections... so you should be able to achieve what you want as follows:

• choose a projection that gives you distance in meters with a suitable accuracy for your region of interest
• use m.set_shape.rectangles(radius=..., radius_crs=...) to draw re-projected rectangles defined in the radius_crs projection
  • note that the rectangles are of course distorted with respect to the crs you use for plotting!
  • if the curvature of the rectangles is not "smooth" enough, you can use the n parameter to increase the number of intermediate points that are calculated between the vertices.
  • ... finally you also need to make sure that the bounding-box of the radius_crs covers your whole data (otherwise some of the rectangles might not show up because they have infinite or zero radius!)

To give you an example how this would work:
(I'll try to put this in the docs properly as soon as I find the time)

from eomaps import Maps, MapsGrid
import numpy as np
lon, lat = np.meshgrid(np.linspace(11, 14, 10), np.linspace(46.5, 48.5, 10))
data = lon+lat

mg = MapsGrid(1, 2, crs=(4326, 31287), figsize=(8, 4))
for m in mg:
    m.add_feature.preset.countries(lw=1, ec="k")
    
    m.set_shape.rectangles(radius=10000, radius_crs=31287, n=500)
    m.set_data(data, lon, lat)
    m.plot_map()
    
    
    m.set_shape.geod_circles(radius=10000, n=500)
    m.plot_map(fc="none", ec="k", lw=0.25)

mg.subplots_adjust(top=0.85)
mg.f.suptitle("Setting shape dimensions in a selected projection.")
mg.m_0_0.ax.set_title("plot epsg=4326 (radius=10km in epsg 31287)", fontsize=8)
mg.m_0_1.ax.set_title("plot epsg=31287 (radius=10km in epsg 31287)", fontsize=8)
mg.m_0_1.add_logo()

[yun881201]

Thank you for answer! The unit of radius in parameters of rectangles is set to be meter like geod_circles if radius_crs=31287?

[raphaelquast]

epsg 31287 is a projection specific for austria... you'd have to find one that suits your data!
(https://epsg.io/31287)