Manual control of tick locations

[jbfaden]

On Autoplot there's been a ticket about manual positioning of the ticks (https://sourceforge.net/p/autoplot/feature-requests/469/), and this should really be in the das2java project. There's a consistent method for specifying tick locations with the tickValues property of the axes. This can be:

• "" default is automatic
• "+15deg" make a tick every degrees
• "0,15,30,45,60,75,90" explicit tick positions
• "+15minute" make a tick every 15 minutes
• "2015-001T00:00,2015-001T04:00"
• *10 ticks at 1,10,100,1000 etc
• "+15deg/5" every 15 degrees with 5 minor tick intervals.

[jbfaden]

This is used in other places, too like:

• contour plots to specify contour locations

[jbfaden]

GraphUtil.calculateManualTicks is where this logic lives.

[jbfaden]

Ali commented that 0.0,30.0,60.0 is used as the format when 0,30,60 would be preferred. I'm correcting this now.

[jbfaden]

• *2 for ticks at 2,4,8,16,32,64

[jbfaden]

This has been working nicely, but we just noticed that +3hr/+1hr for "2022-03-04" resolves incorrectly. The divisor mode works fine (+3hr/3), but it looks like when the + mode is used two time locations' doubles are added together.

Autoplot script to demo:

setScriptDescription('Demos new bug with https://github.com/das-developers/das2java/issues/24')

from org.das2.graph import GraphUtil
ticks= GraphUtil.calculateManualTicks( '+3hr/+1hr',datumRange('2022-03-04'),False)

print ticks.getMajorTicks().get(0)  #2022-03-04T00:00:00.000Z
print ticks.getMinorTicks().get(0)  #2044-05-05T00:00:00.000Z

[jbfaden]

• "10/2,5,8" means minor ticks at "20,50,80,200,500,800,2000,5000,8000" This is a special case to support log axes.
• "+100/20,40,80" means minor ticks at "20,40,80" and that's it. A list of numbers is explicit tick locations.

[jbfaden]

the Contours plot now supports minor ticks.