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List:       qgis-user
Subject:    Re: [Qgis-user] Trouble with select by location between point and line layer
From:       Alexandre Neto <senhor.neto () gmail ! com>
Date:       2015-09-26 11:27:17
Message-ID: CA+H0G_FyW0VB_e=fue0OcoFCHXVeKu3XC55bKHw1Rw-pY7MoKA () mail ! gmail ! com
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Hello João,

In this cases, is very important that when digitizing, either the lines or
the points, your data and your project are in the same coordinate system.
Using on the fly while digitizing may lead to this kind of problems.

Can you copy/paste a line and some points in to a text editor and check if
the coordinates really match?

Alexandre Neto

A 21h48 Sex, 25 de Set de 2015, Goyo <goyodiaz@gmail.com> escreveu:

> Hello João
>
> 2015-09-25 19:39 GMT+02:00 João Carneiro <jhcarneiro@axaeng.com>:
>
> > I imagine that the best way to do this is by using "Select By Location"
> and
> > select all points that intersect the line. Unfortunately this does not
> work,
> > and neither does trying the opposite selection. Trying to select all the
> > points that don't intersect the line gives me 100% of the points even if
> > there were some points that were correctly snapped to the line
> beforehand.
>
> I guess you'll have to check for a distance threshold instead of
> intersection. Floating point arithmetic can't be exact.
>
> Goyo
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> Qgis-user@lists.osgeo.org
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[Attachment #5 (text/html)]

<p dir="ltr">Hello João, </p>
<p dir="ltr">In this cases, is very important that when digitizing, either the lines \
or the points, your data and your project are in the same coordinate system. Using on \
the fly while digitizing may lead to this kind of problems. </p> <p dir="ltr">Can you \
copy/paste a line and some points in to a text editor and check if the coordinates \
really match?</p> <p dir="ltr">Alexandre Neto</p>
<br><div class="gmail_quote"><div dir="ltr">A 21h48 Sex, 25 de Set de 2015,  Goyo \
&lt;<a href="mailto:goyodiaz@gmail.com">goyodiaz@gmail.com</a>&gt; \
escreveu:<br></div><blockquote class="gmail_quote" style="margin:0 0 0 \
.8ex;border-left:1px #ccc solid;padding-left:1ex">Hello João<br> <br>
2015-09-25 19:39 GMT+02:00 João Carneiro &lt;<a href="mailto:jhcarneiro@axaeng.com" \
target="_blank">jhcarneiro@axaeng.com</a>&gt;:<br> <br>
&gt; I imagine that the best way to do this is by using "Select By Location" and<br>
&gt; select all points that intersect the line. Unfortunately this does not work,<br>
&gt; and neither does trying the opposite selection. Trying to select all the<br>
&gt; points that don't intersect the line gives me 100% of the points even if<br>
&gt; there were some points that were correctly snapped to the line beforehand.<br>
<br>
I guess you&#39;ll have to check for a distance threshold instead of<br>
intersection. Floating point arithmetic can&#39;t be exact.<br>
<br>
Goyo<br>
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