Add i.pca algorithm

Author: Médéric Ribreux

python/plugins/processing/algs/grass7/description/i.pca.txt

@@ -0,0 +1,10 @@
+i.pca
+Principal components analysis (PCA) for image processing.
+Imagery (i.*)
+ParameterMultipleInput|input|Name of two or more input raster maps|3|False
+ParameterString|rescale|Rescaling range for output maps. For no rescaling use 0,0|0,255|False|True
+ParameterNumber|percent|Cumulative percent importance for filtering|50.0|99.0|99.0|True
+*ParameterBoolean|-n|Normalize (center and scale) input maps|False
+*ParameterBoolean|-f|Output will be filtered input bands|False
+OutputDirectory|output|Output Directory
+

python/plugins/processing/algs/grass7/ext/i.py

@@ -45,7 +45,7 @@ def multipleOutputDir(alg, field, basename=None):
     # Otherwise, export everything
     else:
         commands = ["for r in $(g.list type=rast); do".format(basename)]
-    commands.append("  r.out.gdal -c -t input=${{r}} output={}/${{r}}.tif createopt=\"TFW=YES,COMPRESS=LZW\"".format(outputDir))
+    commands.append("  r.out.gdal -c -t -f input=${{r}} output={}/${{r}}.tif createopt=\"TFW=YES,COMPRESS=LZW\"".format(outputDir))
     commands.append("done")
     alg.commands.extend(commands)
     alg.outputCommands.extend(commands)
@@ -160,7 +160,7 @@ def exportInputRasters(alg, rasterDic):
     for inputName, outputName in rasterDic.iteritems():
         inputRaster = alg.getParameterValue(inputName)
         outputRaster = alg.getOutputFromName(outputName)
-        command = 'r.out.gdal -c -t --overwrite createopt="TFW=YES,COMPRESS=LZW" input={} output=\"{}\"'.format(
+        command = 'r.out.gdal -c -t -f --overwrite createopt="TFW=YES,COMPRESS=LZW" input={} output=\"{}\"'.format(
             alg.exportedLayers[inputRaster],
             outputRaster.value
         )

python/plugins/processing/algs/grass7/ext/i_pca.py

@@ -0,0 +1,56 @@
+# -*- coding: utf-8 -*-
+
+"""
+***************************************************************************
+    i_pca.py
+    --------
+    Date                 : March 2016
+    Copyright            : (C) 2016 by Médéric Ribreux
+    Email                : medspx at medspx dot fr
+***************************************************************************
+*                                                                         *
+*   This program is free software; you can redistribute it and/or modify  *
+*   it under the terms of the GNU General Public License as published by  *
+*   the Free Software Foundation; either version 2 of the License, or     *
+*   (at your option) any later version.                                   *
+*                                                                         *
+***************************************************************************
+"""
+
+__author__ = 'Médéric Ribreux'
+__date__ = 'March 2016'
+__copyright__ = '(C) 2016, Médéric Ribreux'
+
+# This will get replaced with a git SHA1 when you do a git archive
+
+__revision__ = '$Format:%H$'
+
+from i import multipleOutputDir, verifyRasterNum
+from processing.core.parameters import getParameterFromString
+
+
+def checkParameterValuesBeforeExecuting(alg):
+    return verifyRasterNum(alg, 'input', 2)
+
+
+def processCommand(alg):
+    # Remove output
+    output = alg.getOutputFromName('output')
+    alg.removeOutputFromName('output')
+
+    # Create output parameter
+    param = getParameterFromString("ParameterString|output|output basename|None|False|False")
+    param.value = alg.getTempFilename()
+    alg.addParameter(param)
+
+    alg.processCommand()
+    # re-add output
+    alg.addOutput(output)
+
+
+def processOutputs(alg):
+    param = alg.getParameterFromName('output')
+    multipleOutputDir(alg, 'output', param.value)
+
+    # Delete output parameter
+    alg.parameters.remove(param)