Python is an open source interpreted programming language used in many GIS programs.

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2
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1answer
451 views

QGIS Python Scripting - Syntax definition

After playing around with the Model Builder and looking at the python scripts of what I make, I noticed some syntax which I can't find the definition anywhere. Here is a snippet of the python script ...
5
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2answers
466 views

Accessing arcpy functions from IronPython

I made a few python scripts to automatically optimize and publish my data.. Now i'm thinking about writing a .NET program to manage and run these scripts: the obvious way is invoking them in a ...
4
votes
2answers
6k views

If/then VBScript/Python code equivalent to SQL IN ('x','y',z') expression in ArcGIS Field Calculator?

we need just like the following, only with multiple records selected... have tried the "xyz" in (1,2,3,4,5) SQL code but of course VB Script wants something else. dim f2 if [field1] = "foo" then f2 ...
2
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1answer
2k views

import qgis.core problem with QgsFeature and QgsGeometry

I've tried several previous answers to similar questions - no luck. I run Win7. I installed QGIS 2.2.0 using the OSGeo4W 32-bit installer. Problem 1) from qgis.core import * failed. Solution 1) ...
2
votes
2answers
952 views

Calculate Slope Between Pixels Through Time: A Time Series Trend Analysis

I have a 9 year weekly time series (~500 raster grids of equal cell size and extent). I'm interested in obtaining the regression line slope between pixels (Imagine stacking all 500 grids on top of ...
0
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1answer
217 views

Blank Shapefile output?

When executing the following command string in the active browser, Qgis projects the triangle polygon and associated attribute table correctly. Upon reopening the shapefile in a new browser, the ...
2
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0answers
224 views

How to detect turns of a route?

I'm doing a Python simulation of a vehicle, driving along a specified path. I generate dummy GPS readings, that fetch the current position of the vehicle, with some randomized error added. After a ...
2
votes
2answers
235 views

Issues Reading a table from Geodatabase

I have scripted a process to read a CSV file into a file geodatabase. Then, I want to read this imported file and work on it by adding new fields and calculating values. However, while using the arcpy....
1
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1answer
121 views

How do you determine when user is clicking the end point of an edit sketch using ArcObjects?

I am using vb.net working on ArcObjects. One requirement is to pop up a toolbox once the user click the end point (double click the point under editing status). So I want to know how can I know when ...
0
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1answer
233 views

Programmatically set layer properties Python Init function

Is it possible to set the layer properties Python Init function field programmatically? I've been looking through the qgis 2.2 api but can't seem to find anything on it. Hint, suggestions and ...
1
vote
1answer
2k views

Iterating over selected features in QGIS Processing

I used to be able to iterate over selected features using the following script in v2.0. import processing features = processing.getfeatures(layer) for feature in features: #Do whatever you need ...
3
votes
1answer
389 views

Python MemoryError when running ArcGIS Python Toolbox tool

I have a Python Toolbox (.pyt) containing a single tool. Part of that tool is the following function, which creates a dictionary from an attribute table, where the keys are the rows' OBJECTIDs and the ...
2
votes
1answer
179 views

How to surround a Polygon object with a corridor of specified width?

I'd like to build a corridor surrounding a polygon, so that the corridor's outer bounds all have the same distance to the inner bounds. Like this: I've made this lousy graphic in Paint, since I don'...
1
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0answers
120 views

Highlight paths between two points

I'm new to qgis and very sorry if this is a simple question to ask. IS there a way to highlight the available paths (roads) between two selected points in a road map(in qgis) ? I want to find the ...
2
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0answers
117 views

How to add nodes into graph

I'm new to qgis and in here I want to find a path between two selected points on the map(Roads-vector layer). The points are selected by the user, using mouse clicks. So here I used the astar ...
0
votes
1answer
183 views

In arcgis10.2, can I access arcobjects using python? [duplicate]

I am using python in Arcgis 10.2, but it seems Python cannot meet all my developing demands, from the forum, others recommend to use python to access arc objects,but what they mentioned is the old ...
1
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1answer
56 views

Reinitialize ArcGIS10.0 Python installation

I am developing a Python script for a Toolbox that required a few libraries which I installed manually into C:\Python26\ArcGIS10.0\ and it worked just fine. To make the distribution easier, I dived ...
0
votes
1answer
152 views

no viewable feature when creating line with ogr in python

the python code below produces the expected line shapefile viewable in QGIS import os from osgeo import ogr drv=ogr.GetDriverByName('ESRI Shapefile') if os.path.exists('test.shp'): os.remove('...
1
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1answer
264 views

Howto create complex polygon with pyshp

using the pyshp library (https://code.google.com/p/pyshp/) I am trying to create a "complex" polgon with one hole inside the main-poly plus one island-poly. It should look like this: I used the ...
0
votes
2answers
146 views

Can't get dataProvider object outside of QGIS python Interpreter

Within PyCharm import qgis.core as qgis vector_lyr = qgis.QgsVectorLayer("Point", "distance nodes", "memory") pr = vector_lyr.dataProvider() print pr prints None Within Python Interpreter in QGIS ...
1
vote
1answer
464 views

Raster calculation in for loop returning exit code -1

I've put together a python script that does some calculations on rasters by converting them to NumPy arrays, doing the math, then converting them back to Raster and applying all the same spatial ...
1
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1answer
465 views

Iterative raster calculation script using NumPy arrays breaks after ~10 rasters, returns: “TypeError: Cannot create raster for numpy array.”

Here is my code: #Generate Cumulative Thresholds #5/15/14 import os import glob import arcpy import numpy as np #Enable overwriting output data arcpy.env.overwriteOutput = True ####################...
1
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1answer
81 views

Calculating average of 3 fields where nulls are present

I have created a new field to calculate the average of 3 other fields in a table where nulls are present. Using python as the parser(with no code block) I used this: (!Slope_PCT! or 0 + !Flood_PCT! ...
1
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1answer
89 views

How to count the number of entries a user has selected in a multivalue field of a tool dialogue using Python and ArcGIS 10.2.1

I am currently creating a script that will read data in one (to many) Excel spreadsheet(s) and would like to know how to get a count of the number of spreadsheets entered by the user. The script will ...
1
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1answer
397 views

QGIS Model Builder Script - Possible to merge layers in a folder?

I would like the user to select a folder via the interface in which all the vector shapefiles inside that folder would be merged. I have been using the Model Builder and looking at example scripts ...
0
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0answers
303 views

gdal commands cannot import gdal — possibly ArcGis conflict with separate Python?

I installed ArcGIS 10.1 yesterday (Windows 7 64-bit), but have a separate Python 2.7 installation. Now my gdal does not work correctly anymore. It looks like all commands without the ending "*.py" ...
23
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3answers
14k views

What is the proper syntax and usage for ArcGIS “in_memory” workspace?

I am unclear how best to use the in_memory workspace in ArcGIS. The best resource I have found on the subject is from ESRI on Using in-memory workspace. Unfortunately, the help section is not very ...
2
votes
0answers
63 views

Running algorithm from Processing takes much much longer time than doing it from Qgis GUI

I have a road layer with 32000 features, and I want to find all the intersections. when I use processing->SAGA -> convert polygon/line vertices to points, it is all done in less than 5 seconds. ...
6
votes
1answer
438 views

Changes in synchronized replica not shown in ArcMap or ArcCatalog without refreshing

I am synchronizing a one-way replica in ArcEditor using Python. I tried adding RefreshActiveView and RefreshCatalog to the code, but I still need to refresh the synchronized database to see the ...
4
votes
2answers
454 views

Setting the Centroid of a Set of Polygons

I'm trying to shift a set of rectangle polygons over an area of interest (AOI). I thought it would be as easy as setting the SHAPE@TRUECENTROID of the polygon area of interest to the shapefile/...
-1
votes
2answers
3k views

How to compare values from a column in attribute table with values in Dictionary{}?

I am just entering to the python world, hence the level of my question. Can anyone tell me what Python function should I use to compare values stored in one column in an attribute table with values ...
2
votes
1answer
163 views

How to open most recent directory using PyQGIS?

For example, when I add a vector layer, next time that I want to add another layer it opens up where I chose my last layer from. How would one implement this in Python and/or PyQgis? I'm writing a ...
0
votes
1answer
316 views

Changing $id in a shapefile in QGIS

I need to change the id (feature.id() in the python API or $id in the field calculator) of for features in shapefile layers in qgis, and I need to do it in Python. Is there a way? I tried something ...
1
vote
1answer
301 views

Comparing Features in Python

What I am trying to do is, compare attributes in a shapefile to another updated version of that same shapefile just in a different folder. Right now I am just using the Compare Feature tool, which ...
2
votes
1answer
773 views

How to change attributes with QGIS python?

I have this piece of code which I would like to use for inserting values into column. It does not throw an error, the changes are not written to the source (shapefile). from qgis.utils import iface ...
4
votes
2answers
437 views

Is it a bad idea to convert a File Geodatabase table to a dictionary?

First, what am I trying to do? I am building a Python script that should be called from an ArcMap 10.0 toolbox. This scripts uses (among other inputs) data contained in huge gdb tables. It processes ...
9
votes
5answers
5k views

Compiling Python Scripts that use ArcGIS Geoprocessing Tools?

I've been coding with Python for several months now and have developed some reasonably complex scripts for primarily geoprocessing tasks. That being said, I'm still learning a lot as I'm coming from a ...
2
votes
0answers
268 views

Convert a classification image to aggregated polygon in shapefile using gdal/python

My goal is convert a 2D numpy array to shapefile. The matrix results from a classification, so the numbers have a meaning. I solved my problem, but the solution is somehow involuted and complicated. ...
1
vote
3answers
5k views

How can I translate Modis HDF To GeoTiff

I've a MODIS04 L2, and I want to extract band 8:Image_Optical_Depth_Land_And_Ocean. I use Quantum GIS to open this band, because Quantum GIS see this is not coordinates so this allow me to select ...
10
votes
2answers
5k views

Finding mid-point of line using ArcPy?

How can the mid-point of a polyline be calculated using the geoprocessing framework, e.g. in a Python script? The polyline.centroid property returns The true centroid if it is within or on the ...
0
votes
1answer
199 views

How to calculate/record attachments' file names using Field Calculator?

I have a point feature class containing attachments corresponding to jpg files (sometime more than one jpg per feature). I would like to use the "field calculator" to calculate/record a new field that ...
2
votes
0answers
161 views

Can't remove the little islands when creating a svg map with kartograph.py

I'm new to python and to kartograph. I'm using it to create a map of France, Italy, Portugal and Spain. But I don't want the little islands (mainly the French ones ), causing the generation of a big ...
3
votes
0answers
211 views

python equivalent of spatstat's spatial point process functions

Is there a free python package (i.e. PySAL?) that implements the standard summary statistics for spatial point processes, e.g. the F, G, J, and K functions? I'm happy to use R (i.e. spatstat) if ...
3
votes
1answer
224 views

BV LISA using PySal?

I want to run a LISA with a time series spatially lagged variable using PYSAL. I see that LISA will allow the definition of y & w but not Wy(t-k). Any thoughts how I can get the lagged variable ...
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2answers
427 views

Where to find PySAL toolbox for ArcGIS?

I installed PySAL but i can't find the toolbox for ArcGIS.
1
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1answer
166 views

Calling QgsProjectionSelector from QGIS Python plugin?

I am trying to create a dialog that allows the user to select a coordinate system from either the recently used projections or a general list of all available projections. This would basically offer ...
4
votes
2answers
7k views

arcpy.Delete_management not deleting a geodatabase folder

This script runs fine the first time but fails when run the second time. The issue seems to be that the KMLToLayer_conversion statement creates a file geodatabase (no surprise) that subsequently ...
0
votes
3answers
100 views

Python QC field calculator

I am new to Python and am trying to run a simple QA/QC on a particular set of fields. I basically want to verify that fields x and y add up to z, I may have to incorporate rounding since a small ...
2
votes
2answers
170 views

Comparing 2 fields using Python

I am trying to compare 2 fields(double) using python. I want to round to the nearest 10th and flag those with a "1" that are not equal. Here is what I have at the moment: def Qcontrol(old, new): ...
0
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0answers
37 views

Is it possible to compile a grass addon into a commandline app?

As the title says, I'm wondering if it's possible to take the source of a grass add-on and compile it into a commandline app. Or, alternatively, use the add-on in a python program. Basically, I don'...