Re: [Qgis-user] Principal Component Analysis ?

2017-06-23 Thread Nikos Alexandris
* image [2017-06-23 08:03:42 -0700]: Good afternoon, Hi Laurent, i'm working on windows with several opensource tools (qgis, otb, grass...), I generated several OTB texture indices. Now, i want to evaluate the information 's redundancy thanks to a Principal Component Analysis. => Is it p

Re: [Qgis-user] Principal Component Analysis ?

2017-06-23 Thread Benjamin Ducke
Can you please stop patronizing people? Please assume that GIS users can tell the difference between _exploratory_ and _explanatory_ and are well aware of what specific statistical methods can and cannot achieve. Whether or not someone abuses statistical flexibility is not a question that needs to

[Qgis-user] OT: users in Ottawa or southeastern Ontario?

2017-06-23 Thread Dave Stevens
Would like to have offline discussion Dave -- In modern fantasy (literary or governmental), killing people is the usual solution to the so-called war between good and evil. My books are not conceived in terms of such a war, and offer no simple answers to simplistic questions. - Ursula Le G

Re: [Qgis-user] Principal Component Analysis ?

2017-06-23 Thread Falk Huettmann
Hi, thanks but nope: CANOCO comes from the 1970s and is widely outdated by now, and not achieving (much). Just a few botanists (=not trained statisticians or coders) still use it, if at all. It usually asks the wrong questions and uses pretty old methods that are widely improved by now, e.g. mach

Re: [Qgis-user] Principal Component Analysis ?

2017-06-23 Thread Nicolas Cadieux
Hi, I am not at what needs to be analyzed in this case but yes, canonical analysis needs to be well understood before being used. 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. Cheers Nico

Re: [Qgis-user] Principal Component Analysis ?

2017-06-23 Thread Falk Huettmann
Hi there, in my view and if I may comment here: while R is scary (as stated below), so are probably many of the wrapped R packages really, PCAs are even more scary, and their underlying mindsets, and the real horror starts when such things get implemented into 'homebrews' and such tools, or into

Re: [Qgis-user] Principal Component Analysis ?

2017-06-23 Thread Nicolas Cadieux
Hi, You can use R for PCA. Use the R Commander package to add a GUI. R can be scary at first. Nicolas > Le 23 juin 2017 à 11:03, image [via OSGeo.org] > a écrit : > > Good afternoon, > > i'm working on windows with several opensource tools (qgis, otb, grass...), > > I generated several OT

[Qgis-user] Principal Component Analysis ?

2017-06-23 Thread image
Good afternoon, i'm working on windows with several opensource tools (qgis, otb, grass...), I generated several OTB texture indices. Now, i want to evaluate the information 's redundancy thanks to a Principal Component Analysis. => Is it possible to do that with some opensource tools (otb? qgis?

[Qgis-user] Georeferencer: Meaning of Set Target Resolution?

2017-06-23 Thread Benjamin Ducke
Dear QGIS Users -- I am a bit clueless about the "Set Target Resolution" option in the Raster Georeferencer. The online help is somewhat vague about this: "... define the pixel resolution of the output raster." Does this refer to a pixel scaling factor or "pixels per unit (of what?)" in the outp

Re: [Qgis-user] Python Code of functions in expression builder

2017-06-23 Thread Neumann, Andreas
Hi Benjamin, Of course they can be found in the Python folder ;-) Go to .qgis2 (in Windows in the user profile folder, in Linux/OSX in the home folder), then to "python/plugins/qgsexpressionsplus" or "python/plugins/refFunctions". Self-written custom Python functions end up in "python/express

[Qgis-user] Python Code of functions in expression builder

2017-06-23 Thread Fuenfer-Koenigstein.Benjamin
Hi all, I'm looking for the folder where the python files of functions available in expression builder are installed. I want to get some inspiration for a special custom function I have to write. Thanks for any help! Best regards Benjamin ___ Qgis-us