<div dir="ltr">Hi,<div><br></div><div>thanks but nope:</div><div><br></div><div>CANOCO comes from the 1970s and is widely outdated by now,</div><div>and not achieving (much). </div><div>Just a few botanists (=not trained statisticians or coders) still use it, if at all.</div><div>It usually asks the wrong questions and</div><div>uses pretty old methods that are widely improved by now,</div><div>e.g. machine learning. It all sits there instead, inference from</div><div>predictions. Many publications on that matter.</div><div>Sorry (any programmer knows it that machine learning performs 'very high').</div><div>Like with LMs, GLMs and AIC, p-values or Bayesian stuff, CANOCO does not generalize nor predict so well.<br></div><div><br></div><div>R is free, a hodgepodge of sorts, and thus, the cutting edge stuff does NOT all sit in R (high quality swords have a price, sorry).</div><div>It's reality. Google etc are not programmed in R or with R for good reasons.</div><div>Perhaps a certain blend is helpful, agreed, but hardly anything else.</div><div>R packages also tend to suffer from poor conceptual reviews, e.g. what for and why ?</div><div><br></div><div>Again,</div><div>please be aware about such things.</div><div>Just because it's statistics, coded by your good buddy, freeware, R (or QGIS), it's not all</div><div>automatically good; often the opposite is the case. </div><div><br></div><div>It's a fact and the crux you deal with here.</div><div>A so-called hijacking by some coders and their mindsets; we saw it many times before,</div><div>and it's self-serving.</div><div>CANOCO is a great example for that.</div><div><br></div><div>Kind regards</div><div> Falk</div><div><br></div><div>Falk Huettmann PhD, Associate Professor</div><div>Uni of Alaska Fairbanks UAF</div><div><br></div><div><br></div><div><br></div></div><div class="gmail_extra"><br><div class="gmail_quote">On Fri, Jun 23, 2017 at 11:56 AM, Nicolas Cadieux <span dir="ltr"><<a href="mailto:nicolas.cadieux@archeotec.ca" target="_blank">nicolas.cadieux@archeotec.ca</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="auto"><div></div><div>Hi,</div><div><br></div><div>I am not at what needs to be analyzed in this case but yes, canonical analysis needs to be well understood before being used. </div><div><br></div><div>You can go to Pierre Legendre and Louis Legendre, Numerical Ecology, for help. P Legendre also has a book on Spatial analysis in R that can be found.</div><div><br></div><div>Cheers</div><span class="HOEnZb"><font color="#888888"><div>Nicolas</div></font></span><div><br></div><div>P.S.</div><div><br></div><div>As far as statistical software, R is unbeatable for cutting edge sciences. It is scary because it's a statistical language before being a statistical software. But I agree, some statistics are implement in GIS software without any thought.</div><div><div class="h5"><div><br>Le 23 juin 2017 à 15:11, Falk Huettmann <<a href="mailto:fhuettmann@alaska.edu" target="_blank">fhuettmann@alaska.edu</a>> a écrit :<br><br></div><blockquote type="cite"><div><div dir="ltr">Hi there,<div><br></div><div>in my view and if I may comment here:</div><div>while R is scary (as stated below), so are probably many of the wrapped R packages really,</div><div>PCAs are even more scary, and their underlying mindsets,</div><div>and the real horror starts when such things get</div><div>implemented into 'homebrews' and such tools, or</div><div>into QGIS and just as point and klick.</div><div><br></div><div>As a rule, I would highly suggest to stay clear of such efforts and concepts.</div><div>It's no good science, and not much defendable. Unless well thought out,</div><div>it harms the product and reputation you want to create.</div><div>(for a bad example see Krigging in some major commercial GIS...</div><div> We have seen such things many places).</div><div><br></div><div>There should first be a good debate about statistics, if pursued as tools in QGIS etc.</div><div>Arguably, unless it's predictive (for inference etc) it has no much value these days anymore.</div><div><br></div><div>Agreed,</div><div>it's a tragedy of our time that such old things still happen, all the time,</div><div>and in the sciences. </div><div>But it ain't no good, really, and is no good progress. My word for it.</div><div><br></div><div>(I also agree that it is good to keep avenues open for such</div><div>work, as an option and for people who know what they are doing and why; sure. </div><div>But not more than that. Many bad examples exist all over for decades)</div><div><br></div><div>Feel free to follow up as needed; kind regards</div><div> Falk Huettmann</div><div> Uni of Alaska Fairbanks</div><div><br></div></div><div class="gmail_extra"><br><div class="gmail_quote">On Fri, Jun 23, 2017 at 10:57 AM, Nicolas Cadieux <span dir="ltr"><<a href="mailto:nicolas.cadieux@archeotec.ca" target="_blank">nicolas.cadieux@archeotec.ca</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div></div><div>Hi, </div><div>You can use R for PCA.</div><div>Use the R Commander package to add a GUI. R can be scary at first.</div><div>Nicolas</div><div><br>Le 23 juin 2017 à 11:03, image [via <a href="http://OSGeo.org" rel="nofollow" link="external" target="_blank">OSGeo.org</a>] <<a href="http:///user/SendEmail.jtp?type=node&node=5325361&i=0" rel="nofollow" link="external" target="_blank">[hidden email]</a>> a écrit :<br><br></div><blockquote style="border-left:2px solid #cccccc;padding:0 1em" type="cite"><div>Good afternoon,
<br><br>i'm working on windows with several opensource tools (qgis, otb, grass...),
<br><br>I generated several OTB texture indices. Now, i want to evaluate the information 's redundancy thanks to a Principal Component Analysis.
<br><br>=> Is it possible to do that with some opensource tools (otb? qgis? grass?) Moreover, I would like set a mask AND set a spectral subset (in order to ignore some indices bands which seems "strange" and not relevant to introduce into the process).
<br><br>Could you throw light for me?
<br><br>In advance, thank you very much for your help.
<br><br>Kind regards.
<br>
<br>
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