Mapping archives

[CommonClimate]

LinkedEarth has a high-level discussion going on about converging on some graphics conventions for proxy archives, so they appear reasonably similar whether users map things on the LiPDverse site, in Pyleoclim, GeoChronR, etc. We've been asked to provide input since Python has some limitations that don't exist in Java (where any PNG can be used as a marker).

Background: a lot of this started here

Choices are subjective of course, but a few observations seem sensible:

• one should use similar shapes and color tones for related archives: e.g. same shape for corals and sclerosponges; with a similar tone (e.g. orange vs red).
• We are somewhat limited by these shape options in Matplotlib: https://matplotlib.org/stable/api/markers_api.html
• A non-negotiable is upward green triangles for trees/wood!
• Similarly, ice could be asterisks (~snowflakes) of different shades of blue for different types of ice (Glacier, ground, etc). This can be achieved with marker=(6, 2, 0), color='tab:cyan'
• It makes sense for sediments to be brown, though with the proliferation of types (Marine, Lake, Fluvial, Terrestrial) we need relatively clear differentiators on shape.
• Color choices abound, but color-blindness is a significant concern. This theme has many options.

For reference, these is our current defaults:

PLOT_DEFAULT = {'GroundIce': ['#86CDFA', 'h'],
                     'Borehole': ['#00008b', 'h'],
                     'Coral': ['#FF8B00', 'o'],
                     'Documents': ['#f8d568', 'p'],
                     'GlacierIce': ['#86CDFA', 'd'],
                     'Hybrid': ['#808000', '*'],
                     'LakeSediment': ['#8A4513', '^'],
                     'MarineSediment': ['#8A4513', 's'],
                     'Sclerosponge': ['r', 'o'],
                     'Speleothem': ['#FF1492', 'd'],
                     'Wood': ['#32CC32', '^'],
                     'MolluskShell': ['#FFD600', 'h'],
                     'Peat': ['#2F4F4F', '*'],
                     'Midden': ['#824E2B', 'o'],
                     'FluvialSediment': ['#4169E0','d'],
                     'TerrestrialSediment': ['#8A4513','o'],
                     'Shoreline': ['#add8e6','o'],
                     'Instrumental' : ['#8f21d8', '*'],
                     'Model' : ['#b4a7d6', "d"],
                     'Other': ['k', 'o']
                    }