initial commit

.gitattributes

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+# Auto detect text files and perform LF normalization
+* text=auto
+
+# Custom for Visual Studio
+*.cs     diff=csharp
+*.sln    merge=union
+*.csproj merge=union
+*.vbproj merge=union
+*.fsproj merge=union
+*.dbproj merge=union
+
+# Standard to msysgit
+*.doc	 diff=astextplain
+*.DOC	 diff=astextplain
+*.docx diff=astextplain
+*.DOCX diff=astextplain
+*.dot  diff=astextplain
+*.DOT  diff=astextplain
+*.pdf  diff=astextplain
+*.PDF	 diff=astextplain
+*.rtf	 diff=astextplain
+*.RTF	 diff=astextplain

.gitignore

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+# Byte-compiled / optimized / DLL files
+__pycache__/
+*.py[cod]
+
+# C extensions
+*.so
+
+# Distribution / packaging
+.Python
+env/
+bin/
+build/
+develop-eggs/
+dist/
+eggs/
+lib/
+lib64/
+parts/
+sdist/
+var/
+*.egg-info/
+.installed.cfg
+*.egg
+
+# Installer logs
+pip-log.txt
+pip-delete-this-directory.txt
+
+# Unit test / coverage reports
+htmlcov/
+.tox/
+.coverage
+.cache
+nosetests.xml
+coverage.xml
+
+# Translations
+*.mo
+
+# Mr Developer
+.mr.developer.cfg
+.project
+.pydevproject
+
+# Rope
+.ropeproject
+
+# Django stuff:
+*.log
+*.pot
+
+# Sphinx documentation
+docs/_build/
+
+
+# =========================
+# Operating System Files
+# =========================
+
+# OSX
+# =========================
+
+.DS_Store
+.AppleDouble
+.LSOverride
+
+# Icon must ends with two \r.
+Icon
+
+# Thumbnails
+._*
+
+# Files that might appear on external disk
+.Spotlight-V100
+.Trashes
+
+# Windows
+# =========================
+
+# Windows image file caches
+Thumbs.db
+ehthumbs.db
+
+# Folder config file
+Desktop.ini
+
+# Recycle Bin used on file shares
+$RECYCLE.BIN/
+
+# Windows Installer files
+*.cab
+*.msi
+*.msm
+*.msp

scripts/Create Ring Maps.py

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+"""
+/***************************************************************************
+Name                 : Ring Maps
+Description          : Ring Maps
+Date                 : 31/Dec/2013
+copyright            : (C) 2013 by Minpa Lee
+email                : [email protected]
+reference:
+    http://gis.stackexchange.com/questions/6682/how-to-implement-ringmaps-in-arcgis
+    http://www.esri.com/esri-news/arcuser/fall-2013/looking-at-temporal-changes
+ ***************************************************************************/
+
+/***************************************************************************
+ *                                                                         *
+ *   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.                                   *
+ *                                                                         *
+ ***************************************************************************/
+"""
+##[My Scripts]=group
+##Input_Vector_Layer=vector
+##Comma_separated__fields_or_Ring_number=string a3_2000, a3_2001, a3_2002, a3_2003, a3_2004, a3_2005
+##Output_Ring_Value_Field=string ring_val
+##Ring_Gap=number 1
+##Output_ring_anchor=output vector
+##Output_ring_maps=output vector
+
+from PyQt4.QtCore import *
+from qgis.core import *
+from qgis.gui import *
+from processing.core.VectorWriter import VectorWriter
+import math
+
+# global environment
+DEFAULT_SEGS = 10
+GAPS = Ring_Gap
+if (GAPS >= DEFAULT_SEGS):
+    raise ValueError('Ring_Gap must be smaller than %s' % DEFAULT_SEGS)
+
+# lambda functions
+# math.radians(x)
+to_radian = lambda degree: math.pi / 180.0 * degree
+# math.degrees(x)
+to_degree = lambda radian: radian * (180.0 / math.pi)
+
+# is_number
+def is_number(s):
+    try:
+        float(s)
+        return True
+    except ValueError:
+        return False
+
+# create_point
+def create_point(centroid, radian, radius):
+    dx = math.cos(radian) * radius
+    dy = math.sin(radian) * radius
+    return QgsPoint(centroid.x() + dx, centroid.y() + dy)
+
+# calculate_layer_extent
+def calculate_layer_extent(input_layer):
+    extent = QgsRectangle()
+
+    features = input_layer.getFeatures()
+    for feature in features:
+        geometry = feature.geometry()
+        if extent.isEmpty() :
+            extent = geometry.boundingBox()
+        else:
+            extent.unionRect(geometry.boundingBox())
+
+    if extent.isEmpty() :
+        extent = input_layer.extent()
+
+    return extent
+
+# create_ring_cell
+def create_ring_cell(centroid, from_deg, to_deg, from_radius, to_radius):
+    step = abs(to_deg - from_deg) / DEFAULT_SEGS
+    radian = 0.0
+
+    outer_ring = []
+
+    # first interior
+    for index in xrange(DEFAULT_SEGS  + 1 - GAPS):
+        radian = to_radian(from_deg + (index * step))
+        outer_ring.append(create_point(centroid, radian, from_radius))
+
+    # second outer
+    for index in xrange(DEFAULT_SEGS - GAPS, -1, -1):
+        radian = to_radian(from_deg + (index * step))
+        outer_ring.append(create_point(centroid, radian, to_radius))
+
+    return QgsGeometry.fromPolygon([outer_ring])
+
+# create_spatial_index
+def create_spatial_index(input_layer):
+    spatial_index = QgsSpatialIndex()
+
+    # features dictionary
+    centroid_features = {}
+
+    features = input_layer.dataProvider().getFeatures()
+    for feature in features:
+        # convert to point feature
+        point_feature = QgsFeature(input_layer.dataProvider().fields())
+        point_feature.setFeatureId(feature.id())
+        point_feature.setAttributes(feature.attributes())
+        point_feature.setGeometry(feature.geometry().centroid())
+        centroid_features[point_feature.id()] = point_feature
+
+        spatial_index.insertFeature(point_feature)
+
+    return (spatial_index, centroid_features)
+
+
+#===============================================================
+# run algorithm
+#===============================================================
+input_layer = processing.getObject(Input_Vector_Layer)
+
+# Comma_separated__fields_or_Ring_number
+ring_num = 0
+use_ring_count = False;
+
+if (is_number(Comma_separated__fields_or_Ring_number)):
+    ring_num = int(Comma_separated__fields_or_Ring_number)
+    use_ring_count = True
+else:
+    input_fields = Comma_separated__fields_or_Ring_number.strip().split(',')
+    ring_num = len(input_fields)
+    for idx in xrange(ring_num):
+        input_fields[idx] = input_fields[idx].strip()
+if (ring_num == 0):
+    raise ValueError('Ring number must be greater than zero')
+
+# calculate layer's extent & feature count
+extent = calculate_layer_extent(input_layer) # input_layer.extent()
+feature_count = input_layer.featureCount()
+
+# create spatial index & convert to points
+(spatial_index, centroid_features) = create_spatial_index(input_layer)
+
+center_point = extent.center(); # QgsPoint
+
+minx = extent.xMinimum()
+miny = extent.yMinimum()
+maxx = extent.xMaximum()
+maxy = extent.yMaximum()
+
+radius = (((maxx - minx)**2 + (maxy - miny)**2) **0.5) / 2.0
+radius_interval = radius / ring_num
+
+# Output_Ring_Value_Field
+provider = input_layer.dataProvider()
+ring_fields = provider.fields()
+ring_fields.append(QgsField("ring_num", QVariant.Int))
+ring_fields.append(QgsField(Output_Ring_Value_Field, QVariant.Double))
+
+idx_fields = []
+for idx in xrange(ring_num):
+    if (use_ring_count):
+        idx_fields.append(-1)
+    else:
+        idx_fields.append(ring_fields.indexFromName(input_fields[idx]))
+
+# create vector writer
+ring_writer = VectorWriter(Output_ring_maps, None, ring_fields, QGis.WKBPolygon, input_layer.crs())
+anchor_writer = VectorWriter(Output_ring_anchor, None, provider.fields(), QGis.WKBLineString, input_layer.crs())
+
+step_angle = 360.0 / feature_count
+half_step = step_angle / 2.0
+
+for idx_side in xrange(feature_count):
+    from_deg = half_step + (idx_side * step_angle)
+    to_deg = half_step + ((idx_side + 1) * step_angle)
+    default_radius = radius
+    progress.setPercentage(int(100 * idx_side / feature_count))
+
+    for idx_radius in xrange(ring_num):
+        cell = create_ring_cell(center_point, from_deg, to_deg, default_radius,  default_radius + radius_interval)
+        cell_centroid_point = cell.centroid().asPoint()
+
+        # find nearest feature & create anchor line
+        if (idx_radius == 0):
+            fids = spatial_index.nearestNeighbor(cell_centroid_point, 1)
+            for fid in fids:
+                nearest_feature = centroid_features[fid]
+                nearest_point = nearest_feature.geometry().asPoint()
+
+                anchor_feature = QgsFeature()
+                anchor_feature.setGeometry(QgsGeometry.fromPolyline([nearest_point, cell_centroid_point]))
+                anchor_feature.setAttributes(nearest_feature.attributes())
+                anchor_writer.addFeature(anchor_feature)
+
+                spatial_index.deleteFeature(nearest_feature)
+
+        # create and write ring feature
+        ring_feature = QgsFeature(ring_fields)
+        ring_feature.setGeometry(cell)
+
+        ring_attributes = nearest_feature.attributes()
+        ring_attributes.append(idx_radius + 1)                           # ring_num
+        if (idx_fields[idx_radius] == -1):
+            ring_attributes.append(0)  # default value = 0
+        else:
+            ring_attributes.append(ring_attributes[idx_fields[idx_radius]])  # ring_val
+        ring_feature.setAttributes(ring_attributes)
+        ring_writer.addFeature(ring_feature)
+
+        default_radius += radius_interval
+
+# cleanup
+del ring_writer
+del anchor_writer
+del centroid_features