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

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1answer
350 views

Is there an online reference available for the Fiona and Shapely libraries?

Is there an online reference available for the Fiona and Shapely libraries? I'm thinking a real reference, beside the tutorial-style documentation: http://toblerity.github.io/shapely/manual.html ...
0
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0answers
63 views

Arcpy - loop through subfolders and change mxd settings [duplicate]

I'm trying to run a python script that uses arcpy and os.walk modules. The aim is to find all mxds by specyfying top workspace level only and for the tool to loop through all subdirectories and locate ...
7
votes
2answers
731 views

How can I speed up my arcpy script?

I have written an application that does a lot of geoprocessing using arcpy. Once started, the application itself runs at an acceptable speed, but it is very slow to boot. It can take 30 seconds or so ...
1
vote
1answer
325 views

ArcPy - Dividing every raster cell value by the maximum cell value

I want to divide every cell of a raster by the raster's maximum cell value using ArcPy. Here is what I have done so far. densityRaster = LineDensity(shapefileName, None, "", "", "") maxVal = ...
0
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1answer
1k views

Python Script for shape file to layer conversion

What is the python Script for Shape file to Layer Conversion? I tried the following... import arcpy from arcpy import env env.workspace="working path" ...
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0answers
244 views

Python Script Producing Empty Cost Path Rasters

I'm trying to run a script that will create cost paths for a large number of randomly generated points then assign the cost to those points. But my script is beginning to create cost path rasters ...
1
vote
1answer
879 views

importing osgeo module in ubuntu 10.04

I have problem with importing "osgeo" module in ubuntu 10.04; I have installed GDAL 1.7 from source ( 1)./configure 2)make) however, still in python I cant import osgeo module. I appreciate any hints. ...
2
votes
2answers
650 views

How can I perform an inside clip on a raster file based on another raster file?

I have a raster file that I would like to use to perform an inside clip on another raster file. I have tried using the extract by rectangle tool, but it gives me values ranging from 3.40282e+038 to ...
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0answers
460 views

Install shapely for QGIS on Mac

I know there are a number of similar questions, but none of them have answers that allow me to use shapely in QGIS. In particular I am trying to install the Contour plugin, but this fails with the ...
1
vote
2answers
239 views

How to modify the results of a geological dataset from vertical to horizontal?

I have a 3-D point shapefile of a geological fault dataset consisting of x,y, and z columns. I need to create a raster dataset from this point dataset. I have been trying to do this in ArcGIS; ...
1
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2answers
692 views

Where to find the variables of QgsPolygon and QgsPolyline?

now I want to use QgsPolygon (and Qgspolyline,too) class in python I have a example by using QgsPoint but I don't know how to use in QgsPolygon following is my Qgspoint example feature = ...
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0answers
122 views

Subset a GeoTIFF image into regular grids and extract mean latitude, mean longitude, and mean RGB for each grid

How can I subset a GeoTIFF image with 1000 by 1000 pixels into regular square grids of 50 by 50 pixels (400 grid objects in total); and calculate mean latitude, mean longitude, and mean RGB for each ...
0
votes
1answer
937 views

ArcPy SelectLayerByAttribute Error and how to control GP output layer name

I have a rather long script that first references an SDE feature class (non-versioned) to perform an attribute selection based on a SQL selection. I've been unable to figure out why the script will ...
25
votes
4answers
16k views

Python Script examples for geoprocessing shapefiles without using arcpy

I would like to use a Python script that is not based on arcpy to do things like query a shapefile by attributes, create new layer from selection, and calculate areas of a polygon and convert ...
5
votes
1answer
2k views

How can I create a new layer from the currrent selection?

Is it possible to create a duplicate layer, only displaying the selection from the layer you are duplicating in QuantumGIS? Simular to ArcGIS -> Create Layer from Selected Features. I looked at "How ...
1
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5answers
2k views

String variable substitution in selection expression

I'm trying to put a variable into a string used to do a selection. At the moment it's like this... expression = "'No_Props' > 5 AND %s < 200 AND 'ST_Ori' >60" % metres_field ...
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3answers
2k views

Center of a bounding box

I have bounding box coordinates of my shapefile (fetched from layer.GetExtent() Python with GDAL/OGR): (-38.6102467739459, -38.017601026186576, 33.01563382506067, 33.624945228091406) So I assume ...
1
vote
2answers
109 views

To select one stream segment at a time for processing

I have attached my stream order network image. I have five different order streams. There are several segments in each order. Now my problem is to select one segment of stream at a time for the ...
7
votes
4answers
1k views

Is there any way to get an email when ArcGIS Server services are stopped/down?

Occasionally, but all too often unfortunately, my AGS services just stop for no reason. I don't usually notice this until the users call me and ask why their maps have no data. Is there any way (I ...
2
votes
1answer
4k views

How do I select by location based on selected features with Python?

Is there a way with Python to do Select by Location with the Use selected feature option? I'm trying to automate a process and am running into barriers. I need to be able to select the 2 lines ...
3
votes
1answer
2k views

Change ArcSDE data source for mxds in specific folder using ArcPy?

I've searched all the forums and help and have made progess but recently got an error that has thrown me for a loop - also some mxds are not being changed at all! What I'd like my code to do: Iterate ...
2
votes
1answer
427 views

Need a Python field calculation that works like the DatePart( ) VB Function

I have a field called Abandoned Year (short integer data type) that I am trying to populate with a four digit year from a column called Decommission Date (Date data type). I have done this in the ...
0
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1answer
823 views

AttributeError when I execute a python script

When I execute a python script to assign my database in postgres, I get this Error !! "AttributeError 'psycopg2._psycopg.cursor' object attribute 'execute' is read-only " def ma_fonction(d): # ...
0
votes
1answer
86 views

Anyone recognize this (reference-system related?) pattern of distortion?

I'm new to GIS and was making some progress until getting rather stumped on this one. I've imported what I believe to be lat/lon data based on US FIPS county codes in weather alerts (NOAA SPC). When ...
0
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1answer
94 views

Need to teach myself Python, looking for some suggestions [duplicate]

I am a bit behind the curve here but I am going to teach myself Python, for better or worse, and am looking for any suggestions inre: books, blogs, websites etc. I have little to no experience in ...
2
votes
1answer
437 views

ImportError: No module named qgis.core

I am on Ubuntu 13.04. I get the following error message - Traceback (most recent call last): File "analyse.py", line 1, in <module> from log import shelve File ...
2
votes
1answer
1k views

How to perform a cascaded combine from python script in QGIS?

I'm working with a large dataset, and I need to be able to combine up to 400,000 polygons. I have been using the QgsGeometry::combine(QgsGeometry* geometry) function and simply looping over all ...
3
votes
1answer
376 views

How to create a line layer which connects a point layer to a line layer?

In the map shown below, I have manually created the dummy lines (in green). Using python, and without using PostGIS or sextante, I would like to automate the creation of these dummy links between a ...
4
votes
1answer
442 views

Pick random points in an earth circle

All I need is the ability to create random points within a radius of another point. so given self.fence.latitude and self.fence.longitude and self.fence.radius I should be able to generate random ...
2
votes
1answer
73 views

how to differentiate between common parts of the triangle and extract linestring from it

Can you help me break down shape A to different linestrings: lines 2 & 3 AND line 1? The shape contains three different polygons (A, B, C). I wish to determine the start/end point of each part ...
2
votes
0answers
133 views

Rounding error in qgis point sampling tool

I'm not sure if this is a bug or of it is due to the implementation. I am using a raster that has values greater than 1,000,000 and Qgis displays these numbers in a scientific notation. For instance, ...
1
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1answer
2k views

While looping with arcpy: ERROR 010240: Could not save raster dataset

Hi I am very new to python coding and have been struggling with this for a while I cannot see the reason for this error! Any help will be greatly appreciated. Here is the code that is causing this ...
1
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1answer
2k views

How to append a vector layer using Qgis and Python?

I am working on scripting some data processing using Qgis and Python, but I'm running across issues that I need to debug. Since my data is really large, and run-times can be lengthy, I would like to ...
4
votes
2answers
5k views

use a selection of features in ArcMap in Python script

I am trying to write a python script and am stuck on the first obstacle. I want the user to select features in ArcMap and then use these selected features in a python script. Is that at all possible ...
1
vote
1answer
481 views

Looking for PyQGIS Syntax Examples/Guide

I am a long-time user of arcgis with intermediate experience python scripting for automation of geoprocessing workflows. I am moving towards using QGIS on the regular and I would like to dive into ...
3
votes
1answer
2k views

Iterating through an numpy array and index to a value in another numpy array

I am struggling to get this code to work I want to iterate through an numpy array and based on the result, index to a value in another numpy array and then save that in a new position based on that ...
4
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0answers
2k views

Finding the “center of gravity” of multiple points where points have unequal weights [closed]

I'm trying to reduce a set of lat/lons (each with it's own weight) into one lat/lon that is the center of mass of all of the points. however when I map the results the average point falls no where ...
2
votes
2answers
77 views

How to travers fields of records without introducing them all in the function?

In my previous question I wanted to reach a field in the field calculation; however, it was pretty easy to introduce a few more inputs for that function. Now, I am facing a problem which needs around ...
3
votes
2answers
2k views

Moving cursor backward i.e. opposite of row = rows.next()?

Can anyone tell me if there is a way to go up one row in python cursor? i.e. opposite of row = rows.next()
6
votes
4answers
589 views

Migrate in a new programming GIS language

The last five years I have been working with VBA and ArcObjects for developing a specific application within ArcGIS. That project that began around 2008-2009 carried out with VBA and ArcObjects which ...
3
votes
2answers
783 views

Copying netCDF coordinate system

UPDATE: 7/26/2013 The issue I'm encountering is a known bug with the netCDF-Java API described in ticket TDS-391: A user would like to convert radar data to netCDF format. Unfortunately, the data ...
6
votes
1answer
298 views

Python in ArcGIS: How to add a space between upper and lowercase letters in TOC

I'd like to use python to update the TOC by adding a space (white space) for layer names that are like this: "BoundaryBuffer" or "WaterEdge" and replace them with "Boundary Buffer" or "Water Edge". ...
-1
votes
1answer
81 views

Is it possible to import/run AML script into GRASS?

I have an AML script that has instructions to import tmp files of (grid, network, basin...) is there any way to run the script in GRASS? I tried to converted to Python but I couldn't do it for the ...
4
votes
4answers
955 views

How to rename a file in the output (ArcGIS python)?

raslist=arcpy.ListRasters() for ras in raslist: arcpy.ProjectRaster_management(ras,outfolder2+ras+'_Albers',spatialref2) print ras+' has been reprojected' I was using the above code for ...
7
votes
3answers
996 views

Using PROJ.4 library to transform from local coordinate system coordinates to global coordinate system using ground control points?

I have a point cloud whose coordinates are with respect to a local coordinate system. I also have ground control points with GPS values. Can I convert these local coordinates to a global coordinate ...
3
votes
1answer
413 views

How to sort features in a layer using OGR/Python?

How can I sort the features of an ogr layer by the values of a field? I tried naive variations of def sortlayer(ds, layer, field): lname = layer.GetName() lsort = ds.ExecuteSQL(b'select * ...
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0answers
566 views

Why does XYToLine_management give ExecuteError ERROR 999999 The table was not found?

I've written this script to import a csv file using ArcGIS' flavor of python.. ArcPy.. It seems to run fine up until the XYtoLine tool runs and then it fails.. This is the error message... Traceback ...
6
votes
2answers
2k views

Why is Shapely not installing correctly?

I am trying to run Shapely on a new machine, and tried both installing it from source, using the installer on its webpage, and using pip install shapely. Every reference I try to make from the library ...
0
votes
1answer
1k views

OSRM API - nearest point fed into routing

I am using the OSRM API to (1) determine the nearest point on a road segment from a give random point with http://server:5000/nearest?loc=_lat_,_lon_ The returned coordinates are used then as an ...
9
votes
1answer
5k views

How to add feature class to MXD with ArcPy (Python)? [duplicate]

I am using ArcGIS 10.1 and I am trying to add a feature class that I create to an MXD, so that I can join to it. This all needs to be done using Python. Is this possible?