geo2code disclosure

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valery
Posts: 26
Joined: Thu Mar 15, 2001 9:24 pm

geo2code disclosure

Post by valery »

Hi,

We are a Full Texis user.

Would it be possible to get access to geo2code function's underlying algorithm (coding/decoding + custom 'between' operator)?
Such knowledge would save us trouble of figuring it out ourselves & speed up development -> increase Texis usage faster -> pay you more $$$ sooner :-))

Thanks,
Valery.
bart
Posts: 251
Joined: Wed Apr 26, 2000 12:42 am

geo2code disclosure

Post by bart »

The way a "geocode" works is simple; We use an unsigned-long field with the bits of the lon. and lat. interleaved from MSB to LSB. The LS bits that won't fit into the long are thrown out; hence, on 64 bit boxes it has 1 foot resolution, but on 32 bit boxes its something like +/- 1/8 mile.

ie: if LON = 00000000 and LAT = 11111111, then geocode= 01010101
bart
Posts: 251
Joined: Wed Apr 26, 2000 12:42 am

geo2code disclosure

Post by bart »

I forgot to mention the algorithm last night;

Texis' BTREE comparison has an additional piece of code in the comparison section to eliminate items that fall "out-of-the-box" during a between operation.

While we won't provide source code to this, you could link your program with Texis and get access to it via a SQL call from a C program.
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