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<p>Hi James, <br>
</p>
<p>I for one will be happy to talk about the technical issues of
simplification... though I think at the moment it seems to be
taking a backseat here to bigger issues like building consensus
around the validity of this import. <br>
</p>
<p>Since this is a more technical issue, can I suggest that you
share your data (original and simplified) along with a description
of the methodology you used and any relevant stats on the wiki
page? I'll be curious to see how much shapes have changed vs. how
many points were removed. Perhaps Some measure of
self-intersection between the simplified and unsimplified shapes,
compared with reductions in the average number of nodes per shape?
That's just the first thing that comes to mind - there may be
better ways to assess the quality, especially as it varies between
municipalities.</p>
<p>Someone also raised a concern about orthogonality (is that a
word?) which will need to be measured in this context somehow as
well. <br>
</p>
<p>Thanks,<br>
</p>
<div class="moz-signature">Nate Wessel<br>
<span style="font-size:10px;color:#777">Jack of all trades, Master
of Geography, PhD candidate in Urban Planning<br>
<a href="http://natewessel.com">NateWessel.com</a></span>
<br>
<br>
</div>
<div class="moz-cite-prefix">On 1/19/19 5:01 PM, James wrote:<br>
</div>
<blockquote type="cite"
cite="mid:CANk4qi9ox=B8R89uaj1_TLhPNiGqRTxdtu8Lkz_iCHqSQ_Nu7A@mail.gmail.com">
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<div dir="auto">Is there no one that will analyse the data I've
posted here? <a
href="https://drive.google.com/file/d/1OK83yrPwMW4nefyu-6JsIInu0meK2rW6/view?usp=sharing"
moz-do-not-send="true">https://drive.google.com/file/d/1OK83yrPwMW4nefyu-6JsIInu0meK2rW6/view?usp=sharing</a>
or are we just email thread warriors?</div>
<br>
<div class="gmail_quote">
<div dir="ltr">On Sat., Jan. 19, 2019, 4:29 p.m. Pierre Béland
via Talk-ca <<a href="mailto:talk-ca@openstreetmap.org"
moz-do-not-send="true">talk-ca@openstreetmap.org</a> wrote:<br>
</div>
<blockquote class="gmail_quote" style="margin:0 0 0
.8ex;border-left:1px #ccc solid;padding-left:1ex">
<div>
<div
class="m_-4497941472882512992ydp221d81a2yahoo-style-wrap"
style="font-family:verdana,helvetica,sans-serif;font-size:13px">
<div>
<div>Voici une compilation statistique à partir des
changesets de OSM pour la grande région de Toronto (<span>bbox=-80.8951,42.9142,-78.1046,44.3297</span>).
Depuis </div>
<div><br>
</div>
<div>Pour respecter la politique de confidentialité de
OSM, les contributeurs ne sont identifiés que selon
leur uid.</div>
<div><br>
</div>
<div>Depuis décembre, on compte 6 contributeurs, 889
changesets et 6,621,124 objets édités (noeuds, chemins
ou relations) </div>
<div><br>
</div>
<div>1 immeuble = 5 objets minimum</div>
<div>Le fichier de changeset ne fournit que le nombre
d'objets édités (var num_changes). On ne peut donc à
cette étape-ci que grossièrement estimer le nombre
d'immeubles, sans doute plus de 1 million déjà. A
partir de Overpass, on ne peut facilement extraire les
données. Je vais télécharger dans PostGIS un fichier
récent de l'Ontario et sélectionner les données
éditées depuis le 24 décembre (premier jour avec
édition ) <span><span
style="color:rgb(0,0,0);font-family:verdana,helvetica,sans-serif"> de
ces 6 contributeurs</span></span>. Mon script
Qualité permettra également d'analyser la géométrie
des bâtiments.</div>
<div><br>
</div>
<div>lexique<br>
</div>
<div>changeset nombre de changesets (sessions
d'édition)</div>
<div>num_changes nombre d'objets édités dans la
session</div>
<div>avg_changes moyenne, objets édités par
changeset</div>
<div><br>
</div>
<div><span>
<div>Tableau 1 - Objets édités par contributeur avec
moyenne par changeset</div>
<div><br>
</div>
<div><span>
<table border="0" cellspacing="0">
<colgroup width="133" span="2"></colgroup> <colgroup
width="81"></colgroup> <colgroup width="95"></colgroup>
<colgroup width="91"></colgroup> <tbody>
<tr>
<td align="right" height="17">uid</td>
<td align="right">changesets</td>
<td align="right">num_changes</td>
<td align="right">avg_changes</td>
<td align="right">% cum</td>
</tr>
<tr>
<td align="right" height="17">9266764</td>
<td align="right">457</td>
<td align="right">3,439,242</td>
<td align="right">7,526</td>
<td align="right">52.7%</td>
</tr>
<tr>
<td align="right" height="17">215433</td>
<td align="right">197</td>
<td align="right">1,619,540</td>
<td align="right">8,221</td>
<td align="right">77.6%</td>
</tr>
<tr>
<td align="right" height="17">5214232</td>
<td align="right">151</td>
<td align="right">815,541</td>
<td align="right">5,401</td>
<td align="right">90.1%</td>
</tr>
<tr>
<td align="right" height="17">9343732</td>
<td align="right">78</td>
<td align="right">628,032</td>
<td align="right">8,052</td>
<td align="right">99.7%</td>
</tr>
<tr>
<td align="right" height="17">3016192</td>
<td align="right">3</td>
<td align="right">17,710</td>
<td align="right">5,903</td>
<td align="right">100.0%</td>
</tr>
<tr>
<td align="right" height="17">1919010</td>
<td align="right">3</td>
<td align="right">1,059</td>
<td align="right">353</td>
<td align="right">100.0%</td>
</tr>
<tr>
<td align="left" height="17"><br>
</td>
<td align="right">889</td>
<td align="right">6,521,124</td>
<td align="right">7,335</td>
<td align="left"><br>
</td>
</tr>
</tbody>
</table>
</span><br>
</div>
<div><br>
</div>
<div>Tableau 2 - Objets édités par contributeur -
jour avec moyenne par changeset<br>
</div>
</span></div>
<div><span>
<table border="0" cellspacing="0">
<colgroup width="133" span="2"></colgroup> <colgroup
width="81"></colgroup> <colgroup width="95"></colgroup>
<colgroup width="91"></colgroup> <tbody>
<tr>
<td align="left" height="17">uid</td>
<td align="left">jour</td>
<td align="left">changesets</td>
<td align="left">num_changes</td>
<td align="left">avg_changes</td>
</tr>
<tr>
<td align="right" height="17">5214232</td>
<td align="right">2018-12-28</td>
<td align="right">3</td>
<td align="right">10,324</td>
<td align="right">3,441</td>
</tr>
<tr>
<td align="right" height="17">5214232</td>
<td align="right">2019-01-14</td>
<td align="right">11</td>
<td align="right">58,402</td>
<td align="right">5,309</td>
</tr>
<tr>
<td align="right" height="17">5214232</td>
<td align="right">2019-01-17</td>
<td align="right">9</td>
<td align="right">57,738</td>
<td align="right">6,415</td>
</tr>
<tr>
<td align="right" height="17">9343732</td>
<td align="right">2019-01-16</td>
<td align="right">7</td>
<td align="right">63,490</td>
<td align="right">9,070</td>
</tr>
<tr>
<td align="right" height="17">215433</td>
<td align="right">2018-12-29</td>
<td align="right">8</td>
<td align="right">70,562</td>
<td align="right">8,820</td>
</tr>
<tr>
<td align="right" height="17">5214232</td>
<td align="right">2019-01-16</td>
<td align="right">25</td>
<td align="right">176,942</td>
<td align="right">7,078</td>
</tr>
<tr>
<td align="right" height="17">5214232</td>
<td align="right">2018-12-23</td>
<td align="right">5</td>
<td align="right">29,279</td>
<td align="right">5,856</td>
</tr>
<tr>
<td align="right" height="17">9343732</td>
<td align="right">2019-01-14</td>
<td align="right">5</td>
<td align="right">39,000</td>
<td align="right">7,800</td>
</tr>
<tr>
<td align="right" height="17">5214232</td>
<td align="right">2019-01-12</td>
<td align="right">10</td>
<td align="right">48,329</td>
<td align="right">4,833</td>
</tr>
<tr>
<td align="right" height="17">5214232</td>
<td align="right">2018-12-24</td>
<td align="right">9</td>
<td align="right">54,888</td>
<td align="right">6,099</td>
</tr>
<tr>
<td align="right" height="17">215433</td>
<td align="right">2019-01-08</td>
<td align="right">13</td>
<td align="right">77,332</td>
<td align="right">5,949</td>
</tr>
<tr>
<td align="right" height="17">9266764</td>
<td align="right">2019-01-08</td>
<td align="right">20</td>
<td align="right">156,232</td>
<td align="right">7,812</td>
</tr>
<tr>
<td align="right" height="17">9266764</td>
<td align="right">2019-01-01</td>
<td align="right">9</td>
<td align="right">67,167</td>
<td align="right">7,463</td>
</tr>
<tr>
<td align="right" height="17">9266764</td>
<td align="right">2019-01-07</td>
<td align="right">19</td>
<td align="right">154,837</td>
<td align="right">8,149</td>
</tr>
<tr>
<td align="right" height="17">215433</td>
<td align="right">2019-01-02</td>
<td align="right">30</td>
<td align="right">280,756</td>
<td align="right">9,359</td>
</tr>
<tr>
<td align="right" height="17">9266764</td>
<td align="right">2018-12-24</td>
<td align="right">11</td>
<td align="right">66,162</td>
<td align="right">6,015</td>
</tr>
<tr>
<td align="right" height="17">5214232</td>
<td align="right">2019-01-11</td>
<td align="right">2</td>
<td align="right">6,219</td>
<td align="right">3,110</td>
</tr>
<tr>
<td align="right" height="17">9343732</td>
<td align="right">2019-01-15</td>
<td align="right">10</td>
<td align="right">75,020</td>
<td align="right">7,502</td>
</tr>
<tr>
<td align="right" height="17">9343732</td>
<td align="right">2019-01-11</td>
<td align="right">11</td>
<td align="right">82,844</td>
<td align="right">7,531</td>
</tr>
<tr>
<td align="right" height="17">215433</td>
<td align="right">2018-12-30</td>
<td align="right">20</td>
<td align="right">177,602</td>
<td align="right">8,880</td>
</tr>
<tr>
<td align="right" height="17">9266764</td>
<td align="right">2018-12-31</td>
<td align="right">30</td>
<td align="right">195,300</td>
<td align="right">6,510</td>
</tr>
<tr>
<td align="right" height="17">9343732</td>
<td align="right">2019-01-12</td>
<td align="right">14</td>
<td align="right">111,821</td>
<td align="right">7,987</td>
</tr>
<tr>
<td align="right" height="17">215433</td>
<td align="right">2019-01-03</td>
<td align="right">25</td>
<td align="right">200,002</td>
<td align="right">8,000</td>
</tr>
<tr>
<td align="right" height="17">9266764</td>
<td align="right">2019-01-10</td>
<td align="right">33</td>
<td align="right">260,886</td>
<td align="right">7,906</td>
</tr>
<tr>
<td align="right" height="17">215433</td>
<td align="right">2019-01-09</td>
<td align="right">17</td>
<td align="right">138,489</td>
<td align="right">8,146</td>
</tr>
<tr>
<td align="right" height="17">215433</td>
<td align="right">2018-12-31</td>
<td align="right">21</td>
<td align="right">169,903</td>
<td align="right">8,091</td>
</tr>
<tr>
<td align="right" height="17">5214232</td>
<td align="right">2019-01-09</td>
<td align="right">9</td>
<td align="right">41,664</td>
<td align="right">4,629</td>
</tr>
<tr>
<td align="right" height="17">9266764</td>
<td align="right">2019-01-13</td>
<td align="right">32</td>
<td align="right">266,247</td>
<td align="right">8,320</td>
</tr>
<tr>
<td align="right" height="17">9266764</td>
<td align="right">2018-12-29</td>
<td align="right">36</td>
<td align="right">274,357</td>
<td align="right">7,621</td>
</tr>
<tr>
<td align="right" height="17">9343732</td>
<td align="right">2019-01-10</td>
<td align="right">14</td>
<td align="right">112,606</td>
<td align="right">8,043</td>
</tr>
<tr>
<td align="right" height="17">1919010</td>
<td align="right">2019-01-17</td>
<td align="right">2</td>
<td align="right">973</td>
<td align="right">487</td>
</tr>
<tr>
<td align="right" height="17">9266764</td>
<td align="right">2018-12-26</td>
<td align="right">29</td>
<td align="right">216,701</td>
<td align="right">7,472</td>
</tr>
<tr>
<td align="right" height="17">215433</td>
<td align="right">2019-01-07</td>
<td align="right">12</td>
<td align="right">93,825</td>
<td align="right">7,819</td>
</tr>
<tr>
<td align="right" height="17">5214232</td>
<td align="right">2019-01-10</td>
<td align="right">2</td>
<td align="right">718</td>
<td align="right">359</td>
</tr>
<tr>
<td align="right" height="17">9266764</td>
<td align="right">2019-01-09</td>
<td align="right">25</td>
<td align="right">216,885</td>
<td align="right">8,675</td>
</tr>
<tr>
<td align="right" height="17">5214232</td>
<td align="right">2019-01-08</td>
<td align="right">27</td>
<td align="right">119,761</td>
<td align="right">4,436</td>
</tr>
<tr>
<td align="right" height="17">5214232</td>
<td align="right">2018-12-25</td>
<td align="right">2</td>
<td align="right">10,528</td>
<td align="right">5,264</td>
</tr>
<tr>
<td align="right" height="17">9266764</td>
<td align="right">2019-01-06</td>
<td align="right">18</td>
<td align="right">142,007</td>
<td align="right">7,889</td>
</tr>
<tr>
<td align="right" height="17">215433</td>
<td align="right">2019-01-01</td>
<td align="right">6</td>
<td align="right">58,083</td>
<td align="right">9,681</td>
</tr>
<tr>
<td align="right" height="17">9266764</td>
<td align="right">2019-01-04</td>
<td align="right">7</td>
<td align="right">39,155</td>
<td align="right">5,594</td>
</tr>
<tr>
<td align="right" height="17">1919010</td>
<td align="right">2019-01-16</td>
<td align="right">1</td>
<td align="right">86</td>
<td align="right">86</td>
</tr>
<tr>
<td align="right" height="17">9266764</td>
<td align="right">2019-01-11</td>
<td align="right">22</td>
<td align="right">174,419</td>
<td align="right">7,928</td>
</tr>
<tr>
<td align="right" height="17">9266764</td>
<td align="right">2018-12-25</td>
<td align="right">29</td>
<td align="right">188,931</td>
<td align="right">6,515</td>
</tr>
<tr>
<td align="right" height="17">9266764</td>
<td align="right">2018-12-27</td>
<td align="right">10</td>
<td align="right">67,593</td>
<td align="right">6,759</td>
</tr>
<tr>
<td align="right" height="17">3016192</td>
<td align="right">2018-12-20</td>
<td align="right">3</td>
<td align="right">17,710</td>
<td align="right">5,903</td>
</tr>
<tr>
<td align="right" height="17">215433</td>
<td align="right">2019-01-04</td>
<td align="right">15</td>
<td align="right">128,047</td>
<td align="right">8,536</td>
</tr>
<tr>
<td align="right" height="17">9266764</td>
<td align="right">2018-12-30</td>
<td align="right">14</td>
<td align="right">108,068</td>
<td align="right">7,719</td>
</tr>
<tr>
<td align="right" height="17">9266764</td>
<td align="right">2019-01-15</td>
<td align="right">21</td>
<td align="right">150,419</td>
<td align="right">7,163</td>
</tr>
<tr>
<td align="right" height="17">5214232</td>
<td align="right">2019-01-15</td>
<td align="right">19</td>
<td align="right">116,812</td>
<td align="right">6,148</td>
</tr>
<tr>
<td align="right" height="17">9266764</td>
<td align="right">2019-01-14</td>
<td align="right">17</td>
<td align="right">135,021</td>
<td align="right">7,942</td>
</tr>
<tr>
<td align="right" height="17">9343732</td>
<td align="right">2019-01-13</td>
<td align="right">17</td>
<td align="right">143,251</td>
<td align="right">8,427</td>
</tr>
<tr>
<td align="right" height="17">9266764</td>
<td align="right">2019-01-12</td>
<td align="right">16</td>
<td align="right">120,488</td>
<td align="right">7,531</td>
</tr>
<tr>
<td align="right" height="17">215433</td>
<td align="right">2019-01-06</td>
<td align="right">13</td>
<td align="right">103,233</td>
<td align="right">7,941</td>
</tr>
<tr>
<td align="right" height="17">5214232</td>
<td align="right">2019-01-13</td>
<td align="right">11</td>
<td align="right">57,670</td>
<td align="right">5,243</td>
</tr>
<tr>
<td align="right" height="17">5214232</td>
<td align="right">2019-01-07</td>
<td align="right">4</td>
<td align="right">7,256</td>
<td align="right">1,814</td>
</tr>
<tr>
<td align="right" height="17">215433</td>
<td align="right">2019-01-05</td>
<td align="right">13</td>
<td align="right">99,108</td>
<td align="right">7,624</td>
</tr>
<tr>
<td align="right" height="17">9266764</td>
<td align="right">2019-01-05</td>
<td align="right">4</td>
<td align="right">25,286</td>
<td align="right">6,322</td>
</tr>
<tr>
<td align="right" height="17">9266764</td>
<td align="right">2019-01-16</td>
<td align="right">24</td>
<td align="right">204,397</td>
<td align="right">8,517</td>
</tr>
<tr>
<td align="right" height="17">215433</td>
<td align="right">2019-01-17</td>
<td align="right">2</td>
<td align="right">18,589</td>
<td align="right">9,295</td>
</tr>
<tr>
<td align="right" height="17">215433</td>
<td align="right">2018-12-27</td>
<td align="right">2</td>
<td align="right">4,009</td>
<td align="right">2,005</td>
</tr>
<tr>
<td align="right" height="17">9266764</td>
<td align="right">2019-01-02</td>
<td align="right">13</td>
<td align="right">71,064</td>
<td align="right">5,466</td>
</tr>
<tr>
<td align="right" height="17">9266764</td>
<td align="right">2019-01-03</td>
<td align="right">18</td>
<td align="right">137,620</td>
<td align="right">7,646</td>
</tr>
<tr>
<td align="right" height="17">5214232</td>
<td align="right">2018-12-27</td>
<td align="right">3</td>
<td align="right">19,011</td>
<td align="right">6,337</td>
</tr>
<tr>
<td align="left" height="17"><br>
</td>
<td align="left"><br>
</td>
<td align="right">889</td>
<td align="right">6,521,124</td>
<td align="right">7,335</td>
</tr>
</tbody>
</table>
</span><br>
</div>
<div><br>
</div>
<div class="m_-4497941472882512992ydp221d81a2signature"><span
style="font-style:italic;color:rgb(0,0,191);font-weight:bold"> <br>
<font face="garamond, new york, times, serif">Pierre
</font><br>
</span></div>
</div>
<div><br>
</div>
</div>
</div>
_______________________________________________<br>
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<a href="mailto:Talk-ca@openstreetmap.org" target="_blank"
rel="noreferrer" moz-do-not-send="true">Talk-ca@openstreetmap.org</a><br>
<a href="https://lists.openstreetmap.org/listinfo/talk-ca"
rel="noreferrer noreferrer" target="_blank"
moz-do-not-send="true">https://lists.openstreetmap.org/listinfo/talk-ca</a><br>
</blockquote>
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<pre class="moz-quote-pre" wrap="">_______________________________________________
Talk-ca mailing list
<a class="moz-txt-link-abbreviated" href="mailto:Talk-ca@openstreetmap.org">Talk-ca@openstreetmap.org</a>
<a class="moz-txt-link-freetext" href="https://lists.openstreetmap.org/listinfo/talk-ca">https://lists.openstreetmap.org/listinfo/talk-ca</a>
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