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@jclosure
Forked from javierarce/gist:7886957
Created December 31, 2019 05:33
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Degrees, minutes and seconds to decimal degrees
CREATE OR REPLACE FUNCTION DMS2DD(strDegMinSec varchar)
RETURNS numeric
AS
$$
DECLARE
i numeric;
intDmsLen numeric; -- Length of original string
strCompassPoint Char(1);
strNorm varchar(16) = ''; -- Will contain normalized string
strDegMinSecB varchar(100);
blnGotSeparator integer; -- Keeps track of separator sequences
arrDegMinSec varchar[]; -- TYPE stringarray is table of varchar(2048) ;
dDeg numeric := 0;
dMin numeric := 0;
dSec numeric := 0;
strChr Char(1);
BEGIN
-- Remove leading and trailing spaces
strDegMinSecB := REPLACE(strDegMinSec,' ','');
-- assume no leading and trailing spaces?
intDmsLen := Length(strDegMinSecB);
blnGotSeparator := 0; -- Not in separator sequence right now
-- Loop over string, replacing anything that is not a digit or a
-- decimal separator with
-- a single blank
FOR i in 1..intDmsLen LOOP
-- Get current character
strChr := SubStr(strDegMinSecB, i, 1);
-- either add character to normalized string or replace
-- separator sequence with single blank
If strpos('0123456789,.', strChr) > 0 Then
-- add character but replace comma with point
If (strChr <> ',') Then
strNorm := strNorm || strChr;
Else
strNorm := strNorm || '.';
End If;
blnGotSeparator := 0;
ElsIf strpos('neswNESW',strChr) > 0 Then -- Extract Compass Point if present
strCompassPoint := strChr;
Else
-- ensure only one separator is replaced with a blank -
-- suppress the rest
If blnGotSeparator = 0 Then
strNorm := strNorm || ' ';
blnGotSeparator := 0;
End If;
End If;
End Loop;
-- Split normalized string into array of max 3 components
arrDegMinSec := string_to_array(strNorm, ' ');
--convert specified components to double
i := array_upper(arrDegMinSec,1);
If i >= 1 Then
dDeg := CAST(arrDegMinSec[1] AS numeric);
End If;
If i >= 2 Then
dMin := CAST(arrDegMinSec[2] AS numeric);
End If;
If i >= 3 Then
dSec := CAST(arrDegMinSec[3] AS numeric);
End If;
-- convert components to value
return (CASE WHEN UPPER(strCompassPoint) IN ('S','W')
THEN -1
ELSE 1
END
*
(dDeg + dMin / 60 + dSec / 3600));
End
$$
LANGUAGE 'plpgsql' IMMUTABLE;
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