Data limits (colourbar min/max scale) option to --use_regional_limits

[dvalters]

Colourbar/data min max limits are set from the 98th percentile of the global region (global as in the whole input domain)

Regional masks are effectively zoomed-in areas, so the colourbar is not rescaled to match this. Would be nice to have the option such as --use_regional_limits

[dvalters]

Currently, you can fix limits in a hacky kind of way for temporary figure creation by modding line 368/377/394 in Confrontation.py (Replace min/max calculation with a hard-coded value... 😱)

e.g. lines that calculate min/max in Confrontation.py:

- vabs =  max(abs(limits[pname]["min"]),abs(limits[pname]["min"]))
+ vabs = 40.0# max(abs(limits[pname]["min"]),abs(limits[pname]["min"]))

[dvalters]

Suggested interface from Nathan:

functionality could work like --limit_type KEYWORD:PERCENTILE. Where KEYWORD could be, say, {'global','regional'} and then PERCENTILE would be (0,100) and represent the limits defined by the middle percentile of the data. For example:

--limit_type global:100 would be plotting by global min/max limits
--limit_type regional:98 would be plotting by the [1,99]th percentile across all models but by regions