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Re: st: Choosing the best set of longitude/latitude coordinates from three choices


From   Eric Booth <ebooth@ppri.tamu.edu>
To   "<statalist@hsphsun2.harvard.edu>" <statalist@hsphsun2.harvard.edu>
Subject   Re: st: Choosing the best set of longitude/latitude coordinates from three choices
Date   Wed, 14 Jul 2010 16:29:33 +0000

<>

That's a good point.  My example takes the minimum, not the minimum difference, so my loop in the previous post should be run on the absolute value of the differences that you calculated.

~ Eric
__
Eric A. Booth
Public Policy Research Institute
Texas A&M University
ebooth@ppri.tamu.edu
Office: +979.845.6754

On Jul 14, 2010, at 11:25 AM, Matthew Krauchunas wrote:

> Still messing around with this and I decided to take the absolute
> value of the differences to make it easier.  Thus, the data now looks
> like this:
> 
> oshpd_fac_no	oshpd_lat	oshpd_long	usc_lat	usc_long	intel_lat	intel_long	oshpd_usc_lat_diff	oshpd_usc_long_diff	oshpd_intel_lat_diff	oshpd_intel_long_diff	intel_usc_lat_diff	intel_usc_long_diff
> 206194113	34.22875	-118.3627	34.2298	-118.3629	34.2286	-118.3622	0.001053	0.000237	0.000145	0.000481	0.001198	0.000717
> 206194139	34.13254	-117.8698	34.13291	-117.8695	34.13241	-117.87	0.000370	0.000275	0.000130	0.000153	0.000500	0.000427
> 206194199	34.07075	-118.2026	34.07106	-118.2035	34.07067	-118.2026	0.000309	0.000870	0.000076	0.000015	0.000385	0.000854
> 206194202	34.69315	-118.157	34.69262	-118.1575	34.69285	-118.157	0.000534	0.000465	0.000298	0.000069	0.000237	0.000534
> 206194284	34.14379	-117.9671	34.14771	-117.9673	34.1431	-117.9675	0.003922	0.000198	0.000687	0.000435	0.004608	0.000237
> 206194320	34.03258	-118.3131	37.40501	-122.0915	37.40488	-122.0914	3.372433	3.778336	3.372299	3.778236	0.000134	0.000099
> 206194400	34.25798	-118.5727	34.25804	-118.5728	34.25835	-118.5725	0.000057	0.000031	0.000370	0.000252	0.000313	0.000282
> 206194558	34.28158	-118.4623	34.28167	-118.4608	34.28154	-118.4608	0.000095	0.001503	0.000042	0.001472	0.000137	0.000031
> 206194563	34.27824	-118.3992	34.28155	-118.4024	34.28153	-118.4026	0.003311	0.003250	0.003292	0.003410	0.000019	0.000160
> 
> 
> On Wed, Jul 14, 2010 at 11:19 AM, Matthew Krauchunas
> <krauchunasms@mymail.vcu.edu> wrote:
>> Hello,
>> 
>> The data management process for my dissertation is fraught with
>> obstacles beyond my current Stata abilities, so I am returning to the
>> "well" where everyone has been extremely helpful.
>> 
>> I have some geocoded data from three sources and I need to figure out
>> a way to choose the best set of coordinates.  The source of the
>> coordinates are Intelligentsearch GIS (intel_lat & intel_long), USC
>> GIS (usc_lat & usc_long), and OSHPD provided GIS (oshpd_lat &
>> oshpd_long).  The OSHPD GIS also has 71 missing longitudes and
>> latitudes.  I have calculated the difference between these three sets
>> of coordinates:  Intelligentsearch & USC
>> (intel_usc_lat_diff     intel_usc_long_diff), OSHPD & USC
>> (oshpd_usc_lat_diff oshpd_usc_long_diff), and OSHPD &
>> Intelligentsearch (oshpd_intel_lat_diff oshpd_intel_long_diff).  I
>> need to keep the best coordinates (i.e., from two datasources with the
>> smallest difference), name the new coordinates longitude and latitude,
>> and use the USC coordinates as the default (i.e., use the USC
>> coordinates when the smallest difference is between USC and
>> Intelligentsearch).
>> 
>> Let me provide an example:  oshpd_fac_no 206194320 has a
>> oshpd_usc_lat_diff of -3.372433, oshpd_intel_lat_diff of -3.372299,
>> and a intel_usc_lat_diff of 0.000134. Obviously the OSHPD gis is the
>> problem and the USC latitude needs to be kept as it is my default.
>> 
>> Does anyone have any ideas for this?
>> 
>> Here is some sample data if it helps:
>> 
>> oshpd_fac_no    intel_usc_lat_diff      intel_usc_long_diff     oshpd_usc_lat_diff      oshpd_usc_long_diff     oshpd_intel_lat_diff    oshpd_intel_long_diff   oshpd_long      oshpd_lat       usc_lat usc_long        intel_lat       intel_long
>> 206271717       -2.928555       4.037598        2.928555        -4.037582       0.000000        0.000015        -121.9128       36.56206        33.63351        -117.8752       36.56206        -121.9128
>> 206100833       -0.124664       0.399834        0.123066        -0.401627       -0.001598       -0.001793       -119.4988       37.10662        36.98355        -119.0972       37.10822        -119.497
>> 206491017       -0.086819       0.052116        0.024086        -0.007385       -0.062733       0.044731        -122.4599       38.27798        38.25389        -122.4525       38.34071        -122.5046
>> 206044001       -0.058876       -0.041939       0.058018        0.040482        -0.000858       -0.001457       -121.598        39.78528        39.72726        -121.6385       39.78614        -121.5965
>> 206190123       -0.056854       -0.162796       0.054424        0.182648        -0.002430       0.019852        -118.2801       34.05378        33.99936        -118.4627       34.05621        -118.2999
>> 206281040       -0.050270       -0.041695       0.000572        0.000282        -0.049698       -0.041412       -122.3058       38.31432        38.31374        -122.3061       38.36401        -122.2644
>> 206040974       -0.039154       -0.023483       0.043438        0.026169        0.004284        0.002686        -121.6123       39.7707 39.72726        -121.6385       39.76641        -121.615
>> 206070948       -0.038231       -0.044518       -0.001057       -0.000832       -0.039288       -0.045349       -122.132        37.88853        37.88959        -122.1312       37.92782        -122.0867
>> 206374019       -0.036625       -0.008965       -0.001068       -0.000153       -0.037693       -0.009117       -116.984        32.83546        32.83652        -116.9839       32.87315        -116.9749
>> 206301202       -0.033604       -0.016846       -0.000050       -0.001251       -0.033653       -0.018097       -117.836        33.74546        33.74551        -117.8347       33.77912        -117.8179
>> *



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