topic Re: Mapping t values in Geoprocessing Questions

Mapping t values

ABDALLAMOHAMED — Sat, 17 Feb 2018 20:11:28 GMT

I have my data in a shapefile and I want to classify my t values into two classes using GIS: first class is t value < - 1.96, and the second class is t value > 1.96.. I'm having some difficulty doing that.. Appreciate your input

Re: Mapping t values

DanPatterson_Retired — Sat, 17 Feb 2018 20:49:30 GMT

In a table?

If so, presumably you have a field with the score values. The quickest way would be to add a new field ... maybe a text field... then query the score field for values greater than 1.96. In your new field, do a field calculation (python parser... !YourNewField! = "> 1.96") Clear the query and search for values < 1.96, repeat using "< -1.96".

You could write a function to do this, but the double query and calculate would take as much time

Re: Mapping t values

ABDALLAMOHAMED — Sat, 17 Feb 2018 21:45:15 GMT

Hi dan..Thanks a lot for your input...I will give it a try and let you know..

Appreciated

Re: Mapping t values

ABDALLAMOHAMED — Sat, 17 Feb 2018 22:23:40 GMT

Hi Dan

Please see the attachment. Do you I did it right? Blue color for Black t value on the left is not visible..

Thanks

Re: Mapping t values

DanPatterson_Retired — Sat, 17 Feb 2018 22:44:13 GMT

Zoom in.. they are there mostly in the central core, but the sizes of the areas are small and the mind will blend the colors if you just observe quickly. Don't expect things at the same spatial scale to reflect any patterns that you observe in a numeric pattern.

A tabular view and a spatial view of the same data set can be remarkably different in the information that is portrayed.

Re: Mapping t values

ABDALLAMOHAMED — Sat, 17 Feb 2018 22:51:35 GMT

Yes, but should I just report them the way they are? because there is no way for the reader to zoom in and out?

Thanks a lot

Re: Mapping t values

DanPatterson_Retired — Sat, 17 Feb 2018 23:44:43 GMT

Report what was observed, or provide different views of the data to the user (ie full scale and zoomed in).

As long as you discuss the data, the maps and its interpretation, you can't be faulted. Consider that the peripheral regions may have few observations but they get classed as

> 1.96. An inner area of much smaller size may have many times more observations, but they get classed the same... Even though they are numerically the same, the interpretation might be different.

Re: Mapping t values

ABDALLAMOHAMED — Sun, 18 Feb 2018 00:14:52 GMT

okay, that is really good..

Thanks a lot Dan for your help. Really appreciated.

Best!

Re: Mapping t values

ABDALLAMOHAMED — Sun, 18 Feb 2018 19:35:43 GMT

Hi Dan,

Sorry I just have one more question to ask.. if I need to change the outline of the grid in the map. How would I get rid of the outlines?

Thanks a lot

Best!

Re: Mapping t values

DanPatterson_Retired — Sun, 18 Feb 2018 21:13:18 GMT

Not sure what outline you are talking about... did you put a reference grid on the map?

Re: Mapping t values

ABDALLAMOHAMED — Sun, 18 Feb 2018 22:04:53 GMT

I meant the lines in the maps ( those for census tracts).. But I figured out...

Thanks a lot and have a wonderful weekend

Best wishes