3 replies to this topic

[Luigi]

Hello map lovers...

I'm trying to come up with some maps on ArcGis 9.2 but I'm facing some problems...

The thing is:

I have a shape with the center points of some states. For each center point I have a field with the value of temperature and another for the precipitation for each year (from 1980 to 2005).

What I want to do is to plot these two informations together in a graphic to be displayed inside each state.
Plotting only temperature os precipitation is easy.

My problem is how to plot both at the same time ?

I hope you GIS fans now how to solve this one

Best regards

Luís

[ELeFevre]

Here's my favorite approach (the long way!). It works especially welll if I'm going to be applying symbology in Illustrator/Mapublisher or ArcMap.
I like this method because you end up with a single field that you can work with anywhere.

1. Classify both variables (just on paper...don't actually apply any symbology)
2. Create a new field in the table
3. Use the Attribute selection filter and select each classification range: i.e. SELECT*From STATES WHERE: "Precipitation" = 1 AND "Temperature" = 1
4. Populate the selected fields (features) with a unique identifier in the new field you created. A combination of letters and numbers works well.
5. Apply a single multivariate graphic to the "master field" in Illustrator or in ArcMap

Here's another approach using ArcMap

1. Classify the attributes of both fields and pass the class values into two new fields
2. Once that is complete, you can use "Multiple Attributes" option under the symbology menu
3. Pick one value to color by (Value field) and apply a "Symbol size" (on the right) to the other field

I'm sure there are faster and much better ways to do this. I'm looking forward to see how others handle this.

[rudy]

You could show both features as one point symbol. Size would indicate the amount of precipitation and colour could represent temperature.

If you wanted all the symbols to be the same size, you would have to produce a bivariate colour scheme - a little more complicated but you could do a simple, unrefined version using very fine hatching for one of the variables if you're dealing with area features.

[Luigi]

Thak's...I'll try and see what comes up

looks cool........