Geohash: Difference between revisions

</pre>

=={{header|RPL}}==

{{trans|Python}}

{{works with|HP|48}}

« ROT ROT DUP ∑LIST 2 /

ROT OVER <

ROT OVER 1 + 4 ROLL PUT

ROT SL ROT NOT R→B OR

» '<span style="color:blue">BISECT</span>' STO <span style="color:grey">''@ ( val (mn,mx) bits → (a,b) bits )''</span>

« "0123456789bcdefghjkmnpqrstuvwxyz" "" → coord pre ch32 hash

« { -90 90 } { -180 180 } #0

0 pre 5 * 1 - FOR j

'''IF''' j 2 MOD '''THEN'''

coord 1 GET 4 ROLL ROT <span style="color:blue">BISECT</span> ROT SWAP

'''ELSE'''

coord 2 GET ROT ROT <span style="color:blue">BISECT</span>

'''END'''

'''NEXT'''

1 pre '''START'''

ch32 OVER #31d AND B→R 1 + DUP SUB

'hash' STO+ 32 /

'''NEXT'''

3 DROPN hash

» » '<span style="color:blue">→GEOH</span>' STO <span style="color:grey">''@ ( { lat long } pre → "geohash" )''</span>

« "0123456789bcdefghjkmnpqrstuvwxyz" "" → hash ch32

« "" BIN

1 hash SIZE '''FOR''' j

ch32 hash j DUP SUB POS

1 - 32 + R→B →STR 4 OVER SIZE 1 - SUB +

'''NEXT'''

'hash' STO

{ {-90,90} {-180,180} }

1 hash SIZE '''FOR''' j

j 2 MOD 1 + DUP2 GET

hash j DUP SUB "0" == 1 +

OVER ∑LIST 2 / PUT PUT

'''NEXT'''

» » '<span style="color:blue">GEOH→</span>' STO <span style="color:grey">''@ ( "geohash" → { { latmin latmax } { longmin longmax ) }''</span>

{ 51.433718 -0.214126 } 2 <span style="color:blue">GEOH→</span>

{ 51.433718 -0.214126 } 9 <span style="color:blue">GEOH→</span>

{ 57.649110 10.407440 } 11 <span style="color:blue">GEOH→</span>

{{out}}

<pre>

3: "gc"

2: "gcpuxe0rj"

1: "u4pruydqqvj"

</pre>

RPL floating-point numbers have only 12 significant digits, which could explain the error in the second case.

"gc" <span style="color:blue">GEOH→</span>

"gcpue5hp4" <span style="color:blue">GEOH→</span>

"u4pruydqqvj" <span style="color:blue">GEOH→</span>

{{out}}

<pre>

3: { { 50.625 56.25 } { -11.25 0 } }

2: { { 51.4336967465 51.433739662 } { -.21414756775 -.214104652406 } }

1: { { 57.6491099595 57.649111301 } { 10.4074390233 10.4074403644 } }