Quantcast

MultiPoint intersecting (in all its points) with a non simple linestring

classic Classic list List threaded Threaded
3 messages Options
Reply | Threaded
Open this post in threaded view
|  
Report Content as Inappropriate

MultiPoint intersecting (in all its points) with a non simple linestring

azabala
Hi,

I have this two geometries:

LINESTRING (-34.89284 126.02532, -25.70532 122.96281, -21.05876 117.47142, -25.81092 114.30331, -29.82386 120.74514, -27.60619 128.77101, -21.90359 130.24946, -14.40573 127.18696, -10.7096 117.15461, -13.5609 116.09858, -18.20746 122.75161, -6.48546 129.51024, -2.89493 120.95634, 8.40466 126.23653, 0.80119 126.44773, -8.06951 122.5404, -8.06951 122.5404, -8.06951 122.5404)

MULTIPOINT (-28.914741841726936 124.03284485429363, -13.723360261472408 125.3366439538489, -4.2628609229577705 124.21683965700947)


If I get their intersection matrix in test builder (or directly run a.disjoints(b) ) with JTS 1.9,  I get that they disjoints.

Is this correct?

Best regards.



--
Alvaro Zabala Ordóñez
azabala[en]gmail[punto]com
alvaro.zabala[en]juntadeandalucia[punto]es
Tlf: 954 995 572
Gabinete de Normalización y Calidad
Servicio de Coordinación y Desarrollo de Sistemas Horizontales.
D.G. de Innovación y Administraciones Públicas.
Consejería de Innovación, Ciencia y Empresa, Junta de Andalucía



_______________________________________________
jts-devel mailing list
[hidden email]
http://lists.refractions.net/mailman/listinfo/jts-devel
Reply | Threaded
Open this post in threaded view
|  
Report Content as Inappropriate

Re: MultiPoint intersecting (in all its points) with a non simple linestring

michaelm-2

> LINESTRING (-34.89284 126.02532, -25.70532 122.96281, -21.05876
> 117.47142, -25.81092 114.30331, -29.82386 120.74514, -27.60619
> 128.77101, -21.90359 130.24946, -14.40573 127.18696, -10.7096
> 117.15461, -13.5609 116.09858, -18.20746 122.75161, -6.48546
> 129.51024, -2.89493 120.95634, 8.40466 126.23653, 0.80119 126.44773,
> -8.06951 122.5404, -8.06951 122.5404, -8.06951 122.5404)
>
> MULTIPOINT (-28.914741841726936 124.03284485429363,
> -13.723360261472408 125.3366439538489, -4.2628609229577705
> 124.21683965700947)
>
>
> If I get their intersection matrix in test builder (or directly run
> a.disjoints(b) ) with JTS 1.9,  I get that they disjoints.
>
> Is this correct?
I think this is.
Your multipoint is approximatively located at intersection points of
your self-intersecting linestring, but not exactly (I can measure about
0.0006 of difference on OpenJUMP)
If your multipoint represent intersections of segments which are not
properly noded, I think you will not get intersects = true except if the
point is as close to the true intersection as possible (with double
coordinates). And even with this condition, it may not be very reliable.

Michaël

>
> Best regards.
>
>
>
> --
> Alvaro Zabala Ordóñez
> azabala[en]gmail[punto]com
> alvaro.zabala[en]juntadeandalucia[punto]es
> Tlf: 954 995 572
> Gabinete de Normalización y Calidad
> Servicio de Coordinación y Desarrollo de Sistemas Horizontales.
> D.G. de Innovación y Administraciones Públicas.
> Consejería de Innovación, Ciencia y Empresa, Junta de Andalucía
>
>
> ------------------------------------------------------------------------
>
> _______________________________________________
> jts-devel mailing list
> [hidden email]
> http://lists.refractions.net/mailman/listinfo/jts-devel
>  

_______________________________________________
jts-devel mailing list
[hidden email]
http://lists.refractions.net/mailman/listinfo/jts-devel
Reply | Threaded
Open this post in threaded view
|  
Report Content as Inappropriate

Re: MultiPoint intersecting (in all its points) with a non simple linestring

azabala
Thanks Michael,
Sorry for the "noise".





2008/11/30 Michael Michaud <[hidden email]>

LINESTRING (-34.89284 126.02532, -25.70532 122.96281, -21.05876 117.47142, -25.81092 114.30331, -29.82386 120.74514, -27.60619 128.77101, -21.90359 130.24946, -14.40573 127.18696, -10.7096 117.15461, -13.5609 116.09858, -18.20746 122.75161, -6.48546 129.51024, -2.89493 120.95634, 8.40466 126.23653, 0.80119 126.44773, -8.06951 122.5404, -8.06951 122.5404, -8.06951 122.5404)

MULTIPOINT (-28.914741841726936 124.03284485429363, -13.723360261472408 125.3366439538489, -4.2628609229577705 124.21683965700947)


If I get their intersection matrix in test builder (or directly run a.disjoints(b) ) with JTS 1.9,  I get that they disjoints.

Is this correct?
I think this is.
Your multipoint is approximatively located at intersection points of your self-intersecting linestring, but not exactly (I can measure about 0.0006 of difference on OpenJUMP)
If your multipoint represent intersections of segments which are not properly noded, I think you will not get intersects = true except if the point is as close to the true intersection as possible (with double coordinates). And even with this condition, it may not be very reliable.

Michaël


Best regards.



--
Alvaro Zabala Ordóñez
azabala[en]gmail[punto]com
alvaro.zabala[en]juntadeandalucia[punto]es
Tlf: 954 995 572
Gabinete de Normalización y Calidad
Servicio de Coordinación y Desarrollo de Sistemas Horizontales.
D.G. de Innovación y Administraciones Públicas.
Consejería de Innovación, Ciencia y Empresa, Junta de Andalucía


------------------------------------------------------------------------

_______________________________________________
jts-devel mailing list
[hidden email]
http://lists.refractions.net/mailman/listinfo/jts-devel
 

_______________________________________________
jts-devel mailing list
[hidden email]
http://lists.refractions.net/mailman/listinfo/jts-devel



--
Alvaro Zabala Ordóñez
azabala[en]gmail[punto]com
alvaro.zabala[en]juntadeandalucia[punto]es
Tlf: 954 995 572
Gabinete de Normalización y Calidad
Servicio de Coordinación y Desarrollo de Sistemas Horizontales.
D.G. de Innovación y Administraciones Públicas.
Consejería de Innovación, Ciencia y Empresa, Junta de Andalucía



_______________________________________________
jts-devel mailing list
[hidden email]
http://lists.refractions.net/mailman/listinfo/jts-devel
Loading...