calulate the distance between two zip codes in the US. The Formula language
version is included below.
There are several subscription zip code services available that will make
available a list of all valid zip codes in the country. You can arrange to
have the location of the zip code included in the file. The zip code itself is
great for validating data entry, but there are other ways to use the
information once it is 'in house'. To use this example:
1. Add the code below to a view action button in a database of zip codes.
2. Select one zip code in a view.
3. Click on the button and select a second zip code from the list.
4. See the distance between zip codes.
The script version has been great for calculating the closest vendor for a
company to work with and many similar applications.
Note: I have a small freely distributable DB of zip codes that I could include
with this example code to make it work out of the box.
Take a look and let me know what you think.
ziplist := @DbColumn("";"":"";"ZipCode";1);
zipToUse := @Prompt([OKCANCELLIST]; "Select a Zip Code"; "Select a zip code to
calculate distance from the selected zip."; "";ziplist);
zipRLat := @DbLookup("":"Cache" ; ""; "ZipCode"; zipToUse; "RadLatitude");
zipRLong := @DbLookup("":"Cache" ; ""; "ZipCode"; zipToUse; "RadLongitude");
zipCity := @DbLookup("":"Cache" ; ""; "ZipCode"; zipToUse; "City");
zipState := @DbLookup("":"Cache" ; ""; "ZipCode"; zipToUse; "State");
RadLat2 := zipRLat;
RadLong2 := zipRLong;
(@Sin(RadLatitude) * @Sin(RadLat2) + @Cos(RadLatitude) *
@Cos(RadLat2) * @Cos(@Abs(RadLong2 - RadLongitude)));
RadDist := @ATan(-CalcX / @Sqrt(-CalcX * CalcX + 1)) + 2 * @ATan(1);
DistMI := RadDist * 3958.754;
RndDistMI := @If(DistMi = 0;0;@Integer(DistMI * 10)/10);
@Prompt([OK];"Miles"; "Distance: " + @Text( RndDistMI) + " miles. From " +
City + ", " + State + " to " + zipCity + ", " + zipState + ".")