How do I display negative values through geostats?

[andrewtrobec]

Hello,

I'm busy mapping temperatures for locations around the world and in some cases the value is negative. Unfortunately negative values are not displayed in the map through the geostats command, so I was wondering how to enable them? I've tried setting the marker sizes so that it is the same for all values:

<option name="mapping.markerLayer.markerMaxSize">10</option>
<option name="mapping.markerLayer.markerMinSize">10</option>

But this only makes positive values the same size, negative values are still missing...

Any ideas?

Thank you!

Andrew

[martin_mueller · Accepted solution]

That would make the value the number of cities underneath the marker with that temperature, and would make the label the temperature.

[andrewtrobec]

This is great! The negative value now appears, thank you so much! I can't make this comment the answer... is there a way for you to move it to be an answer?

[martin_mueller]

Try this:

base search | eval category = case(TEMP < 0, "freezing", TEMP < 15, "cold", TEMP < 25, "temperate", TEMP < 35, "hot", true(), "boiling")
| geostats latfield=LAT longfield=LON count by category

[martin_mueller]

You could round to whole degrees, and do a count by TEMP... then colour all reasonable values accordingly.

As long as the negative temperature is considered a value and not a split-by field, this visualization will attempt to draw a pie slice of negative area. Geometry doesn't do that.

[andrewtrobec]

I'm not sure what you mean by "round to whole degrees. and do a count by TEMP" . Wouldn't this still make every value 1?

[andrewtrobec]

Hey Martin,

This makes it visible since it's a count (a positive value) and not the temperature (negative value). I'd like to have the marker so that when I put by cursor on it, it shows the temperature and not the count.

Is this possible you think?

[martin_mueller]

The marker is a pie chart of your various temperature categories, with the temperature used as the size of that category's slice. If you have a negative temperature, you're drawing a pie slice of negative size.

Zoom way out, to let two markers merge into one - you should see the pie.

[martin_mueller]

Maybe it's just me, but I cannot picture a pie slice or marker with a negative-sized area.

KelvinFTW

[andrewtrobec]

I know what you mean, but I don't want the marker to expand or contract based on the value being displayed. I want it to be a constant size despite being a positive or negative value.