[postgis-users] latitude / longitude from wkb_geometry

[Pedro Doria Meunier]

Hi Mark

Oooopsss. Did a mistake on the script there... :S

Where it reads
for ($point=0; $point<$npoints; $point++)

must be replaced with
for ($point=1; $point<$npoints+1; $point++)

pointn() starts at 1 not 0... also the $npoints must go up to the exact nbr
of points returned by numpoints()

Sorry for that.

Also forgot to mention that the coordinates are returned in the form of
dd.ddddd (pgsql spits them out as double precision)

Should you need them presented in another 'format' you need to do the
math...

HTH,
Pedro Doria Meunier

-----Original Message-----
From: postgis-users-bounces at postgis.refractions.net
[mailto:postgis-users-bounces at postgis.refractions.net] On Behalf Of Pedro
Doria Meunier
Sent: segunda-feira, 12 de Fevereiro de 2007 11:09
To: 'PostGIS Users Discussion'
Subject: RE: [postgis-users] latitude / longitude from wkb_geometry

Hi Mark 

Addendum to the previous post...
I didn't notice that the geometry was LINESTRING :]
So what we need here is to concatenate some functions:

SELECT x(pointn(wkb_geometry,0)), y(pointn(wkb_geometry,0)) from masuf;

This will give you the first coordinate of each line.

Should you want to process all coordinates of each linestring here's a
little PHP that might help:

// ------ cut here
<?php
$connection = pg_connect("host=yourhost port=5432 dbname=yourdb
user=yourusername password=yourpassword");
if (!$connection) {
	print("Connection to the database failed.");
	exit;
}
/*
Get all the records from the table.
We get the unique ogc_fid and the corresponding number of points for the
linestring of this entry...
*/
$sql="SELECT ogc_fid, numpoints(wkb_geometry) from masuf";
$myresult=pg_exec($connection, $sql);

for ($row=0; $row<pg_numrows($myresult); $row++) {
	$unique=pg_result($myresult,$row,0);
	$npoints==pg_result($myresult,$row,0);
	// now we process each point in this entry
	for ($point=0; $point<$npoints; $point++) {
	$sql= "SELECT x(pointn(wkb_geometry,$point)),
y(pointn(wkb_geometry,$point)) FROM masuf WHERE ogc_fid='$unique'";
	$presult=pg_exec($connection, $sql);
	$lon=pg_result($presult,0,0);
	$lat=pg_result($presult,0,1);
	/*
	Do whatever you wish with $lon, $lat....
	*/
	}
}
?>
// ------ cut here


If the gurus out there have a more efficient way to do this, I'd be more
than interested in hearing about it! ;-)

HTH,
Pedro Doria Meunier.


-----Original Message-----
From: postgis-users-bounces at postgis.refractions.net
[mailto:postgis-users-bounces at postgis.refractions.net] On Behalf Of mark
Sent: segunda-feira, 12 de Fevereiro de 2007 5:57
To: postgis-users at postgis.refractions.net
Subject: [postgis-users] latitude / longitude from wkb_geometry

how to get latitude and longitude from wkb_geometry?
My table structure is given below
thanks
mark

CREATE TABLE masuf
(
ogc_fid serial NOT NULL,
wkb_geometry geometry,
module char(8),
tlid numeric(10),
side1 numeric(1),
source char(1),
fedirp char(2),
fename char(30),
fetype char(4),
fedirs char(2),
cfcc char(3),
fraddl char(11),
toaddl char(11),
fraddr char(11),
toaddr char(11),
friaddl char(1),
toiaddl char(1),
friaddr char(1),
toiaddr char(1),
zipl numeric(5),
zipr numeric(5),
aianhhfpl numeric(5),
aianhhfpr numeric(5),
aihhtlil char(1),
aihhtlir char(1),
census1 char(1),
census2 char(1),
statel numeric(2),
stater numeric(2),
countyl numeric(3),
countyr numeric(3),
cousubl numeric(5),
cousubr numeric(5),
submcdl numeric(5),
submcdr numeric(5),
placel numeric(5),
placer numeric(5),
tractl numeric(6),
tractr numeric(6),
blockl numeric(4),
blockr numeric(4),
CONSTRAINT masuf_pk PRIMARY KEY (ogc_fid),
CONSTRAINT enforce_dims_wkb_geometry CHECK (ndims(wkb_geometry) = 2),
CONSTRAINT enforce_geotype_wkb_geometry CHECK
(geometrytype(wkb_geometry) = 'LINESTRING'::text OR wkb_geometry IS
NULL),
CONSTRAINT enforce_srid_wkb_geometry CHECK (srid(wkb_geometry) = 4269)
)
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