Select only lines that touch both sides of polygon - PostGIS

The name of the pictureThe name of the pictureThe name of the pictureClash Royale CLAN TAG#URR8PPP











up vote
2
down vote

favorite












I want to select lines that only touch both sides of a polygon. Is there a function in postgis that can do this? See image below. I only want to select lines from the circle on the left where the line touches both sides of the polygon.



enter image description here






postgis polygon select linestring







share|improve this question























  • Is it right to say that both the start point and the end point of the line must touch the outer ring of the polygon?
    – user30184
    4 hours ago










  • and the line must be otherwise totally inside the polygon?
    – Spacedman
    4 hours ago










  • so that ST_Split postgis.net/docs/ST_Split.html "split polygon by line" creates two polygons and "split line by polygon" does not split the line
    – user30184
    4 hours ago










  • ...and the larger of both possible great circle segments between start/end points does not intersect the interior?
    – ThingumaBob
    4 hours ago














up vote
2
down vote

favorite












I want to select lines that only touch both sides of a polygon. Is there a function in postgis that can do this? See image below. I only want to select lines from the circle on the left where the line touches both sides of the polygon.



enter image description here






postgis polygon select linestring







share|improve this question























  • Is it right to say that both the start point and the end point of the line must touch the outer ring of the polygon?
    – user30184
    4 hours ago










  • and the line must be otherwise totally inside the polygon?
    – Spacedman
    4 hours ago










  • so that ST_Split postgis.net/docs/ST_Split.html "split polygon by line" creates two polygons and "split line by polygon" does not split the line
    – user30184
    4 hours ago










  • ...and the larger of both possible great circle segments between start/end points does not intersect the interior?
    – ThingumaBob
    4 hours ago












up vote
2
down vote

favorite









up vote
2
down vote

favorite











I want to select lines that only touch both sides of a polygon. Is there a function in postgis that can do this? See image below. I only want to select lines from the circle on the left where the line touches both sides of the polygon.



enter image description here






postgis polygon select linestring







share|improve this question















I want to select lines that only touch both sides of a polygon. Is there a function in postgis that can do this? See image below. I only want to select lines from the circle on the left where the line touches both sides of the polygon.



enter image description here






postgis polygon select linestring




postgis polygon select linestring






share|improve this question















share|improve this question













share|improve this question




share|improve this question








edited 1 hour ago









Vince

14.2k32445




14.2k32445










asked 4 hours ago









user1655130

606




606











  • Is it right to say that both the start point and the end point of the line must touch the outer ring of the polygon?
    – user30184
    4 hours ago










  • and the line must be otherwise totally inside the polygon?
    – Spacedman
    4 hours ago










  • so that ST_Split postgis.net/docs/ST_Split.html "split polygon by line" creates two polygons and "split line by polygon" does not split the line
    – user30184
    4 hours ago










  • ...and the larger of both possible great circle segments between start/end points does not intersect the interior?
    – ThingumaBob
    4 hours ago
















  • Is it right to say that both the start point and the end point of the line must touch the outer ring of the polygon?
    – user30184
    4 hours ago










  • and the line must be otherwise totally inside the polygon?
    – Spacedman
    4 hours ago










  • so that ST_Split postgis.net/docs/ST_Split.html "split polygon by line" creates two polygons and "split line by polygon" does not split the line
    – user30184
    4 hours ago










  • ...and the larger of both possible great circle segments between start/end points does not intersect the interior?
    – ThingumaBob
    4 hours ago















Is it right to say that both the start point and the end point of the line must touch the outer ring of the polygon?
– user30184
4 hours ago




Is it right to say that both the start point and the end point of the line must touch the outer ring of the polygon?
– user30184
4 hours ago












and the line must be otherwise totally inside the polygon?
– Spacedman
4 hours ago




and the line must be otherwise totally inside the polygon?
– Spacedman
4 hours ago












so that ST_Split postgis.net/docs/ST_Split.html "split polygon by line" creates two polygons and "split line by polygon" does not split the line
– user30184
4 hours ago




so that ST_Split postgis.net/docs/ST_Split.html "split polygon by line" creates two polygons and "split line by polygon" does not split the line
– user30184
4 hours ago












...and the larger of both possible great circle segments between start/end points does not intersect the interior?
– ThingumaBob
4 hours ago




...and the larger of both possible great circle segments between start/end points does not intersect the interior?
– ThingumaBob
4 hours ago










1 Answer
1






active

oldest

votes

















up vote
3
down vote













I would say that to fit your description, the line should be :



  • Completely inside the polygon

  • Have its start and end points touching the boundary of the polygon




SELECT line_id, geom
FROM line a
JOIN polygon b ON ST_Within(a.geom,b.geom)
AND ST_Intersects(ST_StartPoint(a.geom),ST_Boundary(b.geom))
AND ST_Intersects(ST_EndPoint(a.geom),ST_Boundary(b.geom))





share|improve this answer


















  • 1




    The ST_Intersects relationship may not find all points which are "on" a line. Using ST_DWithin with a small tolerance will be more reliable.
    – Vince
    1 hour ago










  • I think, a combination of st_contains (postgis.net/docs/ST_Contains.html) and st_touches (postgis.net/docs/ST_Touches.html) will do the job
    – PieterB
    1 hour ago










Your Answer







StackExchange.ready(function()
var channelOptions =
tags: "".split(" "),
id: "79"
;
initTagRenderer("".split(" "), "".split(" "), channelOptions);

StackExchange.using("externalEditor", function()
// Have to fire editor after snippets, if snippets enabled
if (StackExchange.settings.snippets.snippetsEnabled)
StackExchange.using("snippets", function()
createEditor();
);

else
createEditor();

);

function createEditor()
StackExchange.prepareEditor(
heartbeatType: 'answer',
convertImagesToLinks: false,
noModals: false,
showLowRepImageUploadWarning: true,
reputationToPostImages: null,
bindNavPrevention: true,
postfix: "",
onDemand: true,
discardSelector: ".discard-answer"
,immediatelyShowMarkdownHelp:true
);



);













 

draft saved


draft discarded


















StackExchange.ready(
function ()
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fgis.stackexchange.com%2fquestions%2f299319%2fselect-only-lines-that-touch-both-sides-of-polygon-postgis%23new-answer', 'question_page');

);

Post as a guest

















1 Answer
1






active

oldest

votes








1 Answer
1






active

oldest

votes









active

oldest

votes






active

oldest

votes








up vote
3
down vote













I would say that to fit your description, the line should be :



  • Completely inside the polygon

  • Have its start and end points touching the boundary of the polygon




SELECT line_id, geom
FROM line a
JOIN polygon b ON ST_Within(a.geom,b.geom)
AND ST_Intersects(ST_StartPoint(a.geom),ST_Boundary(b.geom))
AND ST_Intersects(ST_EndPoint(a.geom),ST_Boundary(b.geom))





share|improve this answer


















  • 1




    The ST_Intersects relationship may not find all points which are "on" a line. Using ST_DWithin with a small tolerance will be more reliable.
    – Vince
    1 hour ago










  • I think, a combination of st_contains (postgis.net/docs/ST_Contains.html) and st_touches (postgis.net/docs/ST_Touches.html) will do the job
    – PieterB
    1 hour ago














up vote
3
down vote













I would say that to fit your description, the line should be :



  • Completely inside the polygon

  • Have its start and end points touching the boundary of the polygon




SELECT line_id, geom
FROM line a
JOIN polygon b ON ST_Within(a.geom,b.geom)
AND ST_Intersects(ST_StartPoint(a.geom),ST_Boundary(b.geom))
AND ST_Intersects(ST_EndPoint(a.geom),ST_Boundary(b.geom))





share|improve this answer


















  • 1




    The ST_Intersects relationship may not find all points which are "on" a line. Using ST_DWithin with a small tolerance will be more reliable.
    – Vince
    1 hour ago










  • I think, a combination of st_contains (postgis.net/docs/ST_Contains.html) and st_touches (postgis.net/docs/ST_Touches.html) will do the job
    – PieterB
    1 hour ago












up vote
3
down vote










up vote
3
down vote









I would say that to fit your description, the line should be :



  • Completely inside the polygon

  • Have its start and end points touching the boundary of the polygon




SELECT line_id, geom
FROM line a
JOIN polygon b ON ST_Within(a.geom,b.geom)
AND ST_Intersects(ST_StartPoint(a.geom),ST_Boundary(b.geom))
AND ST_Intersects(ST_EndPoint(a.geom),ST_Boundary(b.geom))





share|improve this answer














I would say that to fit your description, the line should be :



  • Completely inside the polygon

  • Have its start and end points touching the boundary of the polygon




SELECT line_id, geom
FROM line a
JOIN polygon b ON ST_Within(a.geom,b.geom)
AND ST_Intersects(ST_StartPoint(a.geom),ST_Boundary(b.geom))
AND ST_Intersects(ST_EndPoint(a.geom),ST_Boundary(b.geom))






share|improve this answer














share|improve this answer



share|improve this answer








edited 1 hour ago

























answered 4 hours ago









Busu

715




715







  • 1




    The ST_Intersects relationship may not find all points which are "on" a line. Using ST_DWithin with a small tolerance will be more reliable.
    – Vince
    1 hour ago










  • I think, a combination of st_contains (postgis.net/docs/ST_Contains.html) and st_touches (postgis.net/docs/ST_Touches.html) will do the job
    – PieterB
    1 hour ago












  • 1




    The ST_Intersects relationship may not find all points which are "on" a line. Using ST_DWithin with a small tolerance will be more reliable.
    – Vince
    1 hour ago










  • I think, a combination of st_contains (postgis.net/docs/ST_Contains.html) and st_touches (postgis.net/docs/ST_Touches.html) will do the job
    – PieterB
    1 hour ago







1




1




The ST_Intersects relationship may not find all points which are "on" a line. Using ST_DWithin with a small tolerance will be more reliable.
– Vince
1 hour ago




The ST_Intersects relationship may not find all points which are "on" a line. Using ST_DWithin with a small tolerance will be more reliable.
– Vince
1 hour ago












I think, a combination of st_contains (postgis.net/docs/ST_Contains.html) and st_touches (postgis.net/docs/ST_Touches.html) will do the job
– PieterB
1 hour ago




I think, a combination of st_contains (postgis.net/docs/ST_Contains.html) and st_touches (postgis.net/docs/ST_Touches.html) will do the job
– PieterB
1 hour ago

















 

draft saved


draft discarded















































 


draft saved


draft discarded














StackExchange.ready(
function ()
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fgis.stackexchange.com%2fquestions%2f299319%2fselect-only-lines-that-touch-both-sides-of-polygon-postgis%23new-answer', 'question_page');

);

Post as a guest
































































Comments

Post a Comment

Popular posts from this blog

What does second last employer means? [closed]

Image
Clash Royale CLAN TAG #URR8PPP .everyoneloves__top-leaderboard:empty,.everyoneloves__mid-leaderboard:empty margin-bottom:0; up vote -3 down vote favorite Say, for example I have worked in the following companies, Company A => 2010 - 2011 Company B => 2011 - 2012 Company C => 2012 - Till Date Company D => Have offer Now assume Company D is asking to submit documents from my second last employer. So from the list of companies given, which company would be qualified as second last employer? software-industry employer share | improve this question asked Aug 10 '14 at 5:16 Rajaprabhu Aravindasamy 559 1 6 13 closed as off-topic by Jim G., jmort253 ♦ Aug 11 '14 at 1:58 This question appears to be off-topic. The users who voted to close gave this specific reason: "Questions seeking advice on company-specific regulations, agreements, or policies should be directed to your manager or HR department. Questions that address...
Read more

List of Gilmore Girls characters

Image
The season three cast—(Back row): Lane, Michel, Paris, Emily, Richard, Sookie, Miss Patty, Kirk; Front row: Jess, Luke, Lorelai, Rory, Dean This is a list of characters for the comedy-drama television series Gilmore Girls . Contents 1 Main characters 1.1 Lorelai Gilmore 1.2 Rory Gilmore 1.3 Sookie St. James 1.4 Lane Kim 1.5 Michel Gerard 1.6 Luke Danes 1.7 Emily Gilmore 1.8 Richard Gilmore 1.9 Paris Geller 1.10 Dean Forester 1.11 Jess Mariano 1.12 Kirk Gleason 1.13 Jason Stiles 1.14 Logan Huntzberger 2 Major recurring characters 2.1 Christopher Hayden 2.2 Jackson Belleville 2.3 Mrs. Kim 2.4 Tristin DuGray 2.5 Max Medina 2.6 Taylor Doose 2.7 Dave Rygalski 2.8 Marty 3 Recurring characters 3.1 Stars Hollow 3.2 Chilton 3.3 Yale 3.4 Other 4 Notable guest stars 5 Unseen characters 6 Notes 7 References Main characters Actor Character Appearances Season 1 Season 2 Season 3 Season 4 Season 5 Season 6 Season 7 A Year in the Life Lauren Graham Lorelai Gilmore...
Read more

Confectionery

Image
Prepared foods made with a lot of sugar or other cabohydrates "Sweetmeat" redirects here. For the racehorse, see Sweetmeat (horse). Not to be confused with Sweetbread. This Kransekake is a traditional Scandinavian baker's confection. Confectionery is the art of making confections , which are food items that are rich in sugar and carbohydrates. Exact definitions are difficult. [1] In general, though, confectionery is divided into two broad and somewhat overlapping categories, bakers' confections and sugar confections. [2] Bakers' confectionery, also called flour confections , includes principally sweet pastries, cakes, and similar baked goods. Sugar confectionery includes candies ( sweets in British English), candied nuts, chocolates, chewing gum, bubble gum, pastillage, and other confections that are made primarily of sugar. In some cases, chocolate confections (confections made of chocolate) are treated as a separate category, as are sugar-free versions of ...
Read more