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List:       postgis-users
Subject:    Re: [postgis-users] ST_Intersection does not preserve M value
From:       Bo Guo <bo.guo () gisticinc ! com>
Date:       2019-05-07 14:17:19
Message-ID: 6cf490ad-27c7-c8c3-e008-727ef6656033 () gisticinc ! com
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FME, which sources from GEOS 
(https://cdn.safe.com/resources/fme/FMEDesktop_Legal_Notices_2019.0.pdf), 
did not handle the measurement with its Clipper transformer until about 
two years ago.  Wonder if they achieved this through direct update the 
GEOS lib or through post-GEOS enhancement.

On 5/6/19 2:53 PM, Martin Davis wrote:
> Not exactly the same thing - I believe that ticket is referring to 
> just the WKB format handling?
>
> I can make a ticket for measure handling by the overlay operations if 
> there isn't one already.
>
> On Mon, May 6, 2019 at 11:31 AM Darafei "Komяpa" Praliaskouski 
> <me@komzpa.net <mailto:me@komzpa.net>> wrote:
>
>     It's in backlog for 6 years already I believe:
>     https://trac.osgeo.org/geos/ticket/466
>
>     пн, 6 мая 2019, 19:33 карыстальнік Martin Davis
>     <mtnclimb@gmail.com <mailto:mtnclimb@gmail.com>> напісаў:
>
>         It should be possible to post-process GEOS results to
>         re-populate the M values if present.  Linear interpolation
>         could be used to estimate values at intra-segment points.  We
>         can put this on the list for future development.
>
>         On Mon, May 6, 2019 at 4:48 AM Darafei "Komяpa" Praliaskouski
>         <me@komzpa.net <mailto:me@komzpa.net>> wrote:
>
>             Hi,
>
>             GEOS operations do not preserve M, but sometimes preserve
>             Z. You can try
>             ST_SwapOrdinates(ST_Intersection(ST_SwapOrdinates(geom,
>             'zm'),...), 'zm').
>
>             On Thu, May 2, 2019 at 5:19 AM Bo Guo
>             <bo.guo@gisticinc.com <mailto:bo.guo@gisticinc.com>> wrote:
>
>                 Hi there,
>
>                 I was trying to cut a portion of the LRS route with an
>                 area using
>                 ST_Intersection.  However the resulting route no
>                 longer carries measure
>                 value.  The behavior is the same for version 9.6 or
>                 the latest version
>                 11.  Anyone has any suggestions?
>
>                 Thanks!
>
>                 Bo
>                 _______________________________________________
>                 postgis-users mailing list
>                 postgis-users@lists.osgeo.org
>                 <mailto:postgis-users@lists.osgeo.org>
>                 https://lists.osgeo.org/mailman/listinfo/postgis-users
>
>
>
>             -- 
>             Darafei Praliaskouski
>             Support me: http://patreon.com/komzpa
>             _______________________________________________
>             postgis-users mailing list
>             postgis-users@lists.osgeo.org
>             <mailto:postgis-users@lists.osgeo.org>
>             https://lists.osgeo.org/mailman/listinfo/postgis-users
>
>         _______________________________________________
>         postgis-users mailing list
>         postgis-users@lists.osgeo.org
>         <mailto:postgis-users@lists.osgeo.org>
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>
>     _______________________________________________
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>     postgis-users@lists.osgeo.org <mailto:postgis-users@lists.osgeo.org>
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>
>
> _______________________________________________
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-- 
Bo Guo, PhD, PE
Gistic Research, Inc.
2033 E Warner Rd. Ste 105
Tempe, AZ 85284
www.gisticinc.com
Tel: 480-656-9962

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    <p>FME, which sources from GEOS
(<a class="moz-txt-link-freetext" \
href="https://cdn.safe.com/resources/fme/FMEDesktop_Legal_Notices_2019.0.pdf">https://cdn.safe.com/resources/fme/FMEDesktop_Legal_Notices_2019.0.pdf</a>),
  did not handle the measurement with its Clipper transformer until
      about two years ago.  Wonder if they achieved this through direct
      update the GEOS lib or through post-GEOS enhancement. <br>
    </p>
    <div class="moz-cite-prefix">On 5/6/19 2:53 PM, Martin Davis wrote:<br>
    </div>
    <blockquote type="cite"
cite="mid:CAK2ens1HL-eLMibPj+XQ4Sn0eK745TFfXYZdLF4zsVPJZBUKzg@mail.gmail.com">
      <meta http-equiv="content-type" content="text/html; charset=UTF-8">
      <div dir="ltr">Not exactly the same thing - I believe that ticket
        is referring to just the WKB format handling?
        <div><br>
        </div>
        <div>I can make a ticket for measure handling by the overlay
          operations if there isn't one already.</div>
      </div>
      <br>
      <div class="gmail_quote">
        <div dir="ltr" class="gmail_attr">On Mon, May 6, 2019 at 11:31
          AM Darafei "Komяpa" Praliaskouski &lt;<a
            href="mailto:me@komzpa.net" moz-do-not-send="true">me@komzpa.net</a>&gt;
          wrote:<br>
        </div>
        <blockquote class="gmail_quote" style="margin:0px 0px 0px
          0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
          <div dir="auto"><span
              style="font-family:sans-serif;font-size:12.8px">It's in
              backlog for 6 years already I believe: </span><a
              href="https://trac.osgeo.org/geos/ticket/466"
style="text-decoration-line:none;color:rgb(66,133,244);font-family:sans-serif;font-size:12.8px"
                
              target="_blank" \
moz-do-not-send="true">https://trac.osgeo.org/geos/ticket/466</a></div>  <br>
          <div class="gmail_quote">
            <div dir="ltr" class="gmail_attr">пн, 6 мая 2019, 19:33
              карыстальнік Martin Davis &lt;<a
                href="mailto:mtnclimb@gmail.com" target="_blank"
                moz-do-not-send="true">mtnclimb@gmail.com</a>&gt;
              напісаў:<br>
            </div>
            <blockquote class="gmail_quote" style="margin:0px 0px 0px
              0.8ex;border-left:1px solid
              rgb(204,204,204);padding-left:1ex">
              <div dir="ltr">It should be possible to post-process GEOS
                results to re-populate the M values if present.  Linear
                interpolation could be used to estimate values at
                intra-segment points.  We can put this on the list for
                future development.</div>
              <br>
              <div class="gmail_quote">
                <div dir="ltr" class="gmail_attr">On Mon, May 6, 2019 at
                  4:48 AM Darafei "Komяpa" Praliaskouski &lt;<a
                    href="mailto:me@komzpa.net" rel="noreferrer"
                    target="_blank" moz-do-not-send="true">me@komzpa.net</a>&gt;
                  wrote:<br>
                </div>
                <blockquote class="gmail_quote" style="margin:0px 0px
                  0px 0.8ex;border-left:1px solid
                  rgb(204,204,204);padding-left:1ex">
                  <div dir="ltr">Hi,
                    <div><br>
                    </div>
                    <div>GEOS operations do not preserve M, but
                      sometimes preserve Z. You can try
                      ST_SwapOrdinates(ST_Intersection(ST_SwapOrdinates(geom,
                      'zm'),...), 'zm').</div>
                  </div>
                  <br>
                  <div class="gmail_quote">
                    <div dir="ltr" class="gmail_attr">On Thu, May 2,
                      2019 at 5:19 AM Bo Guo &lt;<a
                        href="mailto:bo.guo@gisticinc.com"
                        rel="noreferrer" target="_blank"
                        moz-do-not-send="true">bo.guo@gisticinc.com</a>&gt;
                      wrote:<br>
                    </div>
                    <blockquote class="gmail_quote" style="margin:0px
                      0px 0px 0.8ex;border-left:1px solid
                      rgb(204,204,204);padding-left:1ex">Hi there,<br>
                      <br>
                      I was trying to cut a portion of the LRS route
                      with an area using <br>
                      ST_Intersection.  However the resulting route no
                      longer carries measure <br>
                      value.  The behavior is the same for version 9.6
                      or the latest version <br>
                      11.  Anyone has any suggestions?<br>
                      <br>
                      Thanks!<br>
                      <br>
                      Bo<br>
                      _______________________________________________<br>
                      postgis-users mailing list<br>
                      <a href="mailto:postgis-users@lists.osgeo.org"
                        rel="noreferrer" target="_blank"
                        moz-do-not-send="true">postgis-users@lists.osgeo.org</a><br>
                      <a
                        href="https://lists.osgeo.org/mailman/listinfo/postgis-users"
                        rel="noreferrer noreferrer" target="_blank"
                        \
moz-do-not-send="true">https://lists.osgeo.org/mailman/listinfo/postgis-users</a></blockquote>
  </div>
                  <br clear="all">
                  <div><br>
                  </div>
                  -- <br>
                  <div dir="ltr"
class="gmail-m_7686164059452819975m_7071114689345428288gmail-m_-9118222508503133905gmail_signature">
  <div dir="ltr">
                      <div>
                        <div>Darafei Praliaskouski</div>
                        <div>Support me: <a
                            href="http://patreon.com/komzpa"
                            rel="noreferrer" target="_blank"
                            \
moz-do-not-send="true">http://patreon.com/komzpa</a></div>  </div>
                    </div>
                  </div>
                  _______________________________________________<br>
                  postgis-users mailing list<br>
                  <a href="mailto:postgis-users@lists.osgeo.org"
                    rel="noreferrer" target="_blank"
                    moz-do-not-send="true">postgis-users@lists.osgeo.org</a><br>
                  <a
                    href="https://lists.osgeo.org/mailman/listinfo/postgis-users"
                    rel="noreferrer noreferrer" target="_blank"
                    moz-do-not-send="true">https://lists.osgeo.org/mailman/listinfo/postgis-users</a></blockquote>
  </div>
              _______________________________________________<br>
              postgis-users mailing list<br>
              <a href="mailto:postgis-users@lists.osgeo.org"
                rel="noreferrer" target="_blank" \
moz-do-not-send="true">postgis-users@lists.osgeo.org</a><br>  <a
                href="https://lists.osgeo.org/mailman/listinfo/postgis-users"
                rel="noreferrer noreferrer" target="_blank"
                moz-do-not-send="true">https://lists.osgeo.org/mailman/listinfo/postgis-users</a></blockquote>
  </div>
          _______________________________________________<br>
          postgis-users mailing list<br>
          <a href="mailto:postgis-users@lists.osgeo.org" target="_blank"
            moz-do-not-send="true">postgis-users@lists.osgeo.org</a><br>
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            href="https://lists.osgeo.org/mailman/listinfo/postgis-users"
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      <pre class="moz-quote-pre" \
wrap="">_______________________________________________ postgis-users mailing list
<a class="moz-txt-link-abbreviated" \
href="mailto:postgis-users@lists.osgeo.org">postgis-users@lists.osgeo.org</a> <a \
class="moz-txt-link-freetext" \
href="https://lists.osgeo.org/mailman/listinfo/postgis-users">https://lists.osgeo.org/mailman/listinfo/postgis-users</a></pre>
  </blockquote>
    <div class="moz-signature">-- <br>
      Bo Guo, PhD, PE <br>
      Gistic Research, Inc.<br>
      2033 E Warner Rd. Ste 105 <br>
      Tempe, AZ 85284 <br>
      <a href="" "http:="" www.gisticinc.com"="">www.gisticinc.com</a> <br>
      Tel: 480-656-9962
    </div>
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