Run difficulty analyses

[dhimmel]

We don't currently include run difficulty in our analyses. Some possible options would be:

• Run counts or combined vertical by difficulty, perhaps with a pie chart to show the difficulty distribution for a ski area
• Distributions of max slope (or average slope) by run difficulty.
• Orientation histograms where bars are stacked by difficulty (or perhaps steepness bins). Suggested by the head of patrol at Saskaden Six, Tim McGreevy, while on a backcountry tour of Skidoo Mountain VT today.

[dhimmel]

Tracking progress:

• dd4580c

[dhimmel]

Note that we currently only have elevation at each run coordinate and not at any intermediate coordinates. OpenSkiMap appears to compute elevation and slope at interpolated points along the runs, which makes several slope-based analyses much stronger.

Update: the elevation profiles are actually available in the runs.geojson download at properties.elevationProfile!

[dhimmel]

https://steepseeker.com/about performs analyses of run difficulty based on steepness.