Allow to overwrite multiple sections in one section statement and allow for interpolation in that statement

[MFraters]

Currently sections can only overwrite one coordinate. Although this works, it can lead to very complicated input files when you have a slab which is different on every coordinate. It would therefore be useful to allow users to overwrite multiple sections of a slab at the same time and overwrite it in a way which interpolates between two defined sections.

Note there there is already a linear interpolation between sections, but that only works between two coordinates. When you need more coordinates, it requires you to do this by hand.

Current input code

	       "sections":[{"coordinate":0,
			    "segments":[{"length":100e3,"thickness":[100e3],"angle":[0,50]},
				        {"length":100e3,"thickness":[100e3],"angle":[50]}]},
			    {"coordinate":1,
			    "segments":[{"length":100e3,"thickness":[100e3],"angle":[0,40]},
				        {"length":100e3,"thickness":[100e3],"angle":[40]}]},
			   {"coordinate":2,
			    "segments":[{"length":100e3,"thickness":[100e3],"angle":[0,30]},
				        {"length":100e3,"thickness":[100e3],"angle":[30]}]},
			   {"coordinate":3,
			    "segments":[{"length":100e3,"thickness":[100e3],"angle":[0,20]},
				        {"length":100e3,"thickness":[100e3],"angle":[20]}]},
			   {"coordinate":4,
			    "segments":[{"length":100e3,"thickness":[100e3],"angle":[0,20]},
				        {"length":100e3,"thickness":[100e3],"angle":[20]}]},
                          ]

proposed input code:

	       "sections":[{"coordinate":[0,3],
			    [
                             {"segments":[{"length":100e3,"thickness":[100e3],"angle":[0,50]},
				         {"length":100e3,"thickness":[100e3],"angle":[50]}]}},
                             {"segments":[{"length":100e3,"thickness":[100e3],"angle":[0,20]},
				         {"length":100e3,"thickness":[100e3],"angle":[20]}]}
                            ],
			   [{"coordinate":4,
			    {"segments":[{"length":100e3,"thickness":[100e3],"angle":[0,20]},
				        {"length":100e3,"thickness":[100e3],"angle":[20]}]}}],
                          ]

[MFraters]

This is not going to work as I had hoped. The issue has to do with the different models (temperature, composition and grains). Although it is relatively easy to linearly interpolate between fro example two different temperature models, you can't use that to fill a new coordinate. The only way this could work if I restrict it to having the same models on both sides, which I think is reasonable.

[WenjingZhu56]

Hi @MFraters ,

I am trying to set up a subducting slab with its thickness varying along strike (here: #861). This issue seems similar with mine. Do you have some suggestion now? Thank you!

[MFraters]

Dear @WenjingZhu56
This issue is about adding a new feature, which would simplify the input file. #861 is a bug report, which seems to be resolved by #799 as pointed out by @danieldouglas92 . You can try if that pull request fixes your issues.