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

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1answer
378 views

arcpy move attributes from one column to another on a joined layer

Sort of new to Python. In Arcmap you can calculate a field on a joined table to just move the attributes from one column to another with just an = sign. Since my layer has feature linked anno on 7 ...
4
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2answers
588 views

Using Python and open source modules, how can I perform Raster Calculator functions?

I would like to perform mathematical functions similar to those you would use Raster Calculator for in ArcMap, however I'd like to do it in Python without using the Arcpy module. I have the osgeo ...
1
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2answers
867 views

Get the vertices on a LineString either side of a Point

I have a shapely LineString and defined a shapely Point which lies along the LineString. How can I find the vertices of the LineString which lie either side of the point? (split the line in two). ...
0
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1answer
312 views

Efficient algorithms for recovering watershed boundaries?

This is somewhat related to a previous question I asked: What Algorithm is used by ArcGIS Watershed tool? I was wondering if there is a more efficient way to calculate catchment areas if you are ...
3
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1answer
544 views

Converting x, y, zoom for Calculating tile bounds

i am working on calculating tile bounds lat lon from x,y,z tile coordinate. i have looked gdal2tiles code structure and i have found this good function: def TileLatLonBounds( tx, ty, zoom ): "Returns ...
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1answer
313 views

create a pie shaped object in shapely and export to gis polygon object

I would like to create a pie chart-shaped polygon with concentric layers like so: I can create this simple object with: from math import sin, cos, radians from shapely.geometry import ...
1
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1answer
385 views

Python ogr2ogr language character encoding

In python script i'm exporting .shp files to .csv/.gpx/.kml import ogr, ogr2ogr ... ogr2ogr.main(["","-f", "CSV", csvfile, shpfile, "-lco", "GEOMETRY=AS_WKT", "-lco", "SEPARATOR=SEMICOLON"]) ...
0
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1answer
163 views

How can I force TileCache to NOT render missing tiles (read only mode)?

I have a working disk TileCache that I do not want additional images to be rendered and saved to disk. Is it possible to force TileCache to a "read-only" mode? At the moment, I have set the folder ...
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0answers
60 views

how to open a layer's table in a map document

Trying to create a map document programmatically. Added a featureclass as a layer. When I open the map document in ArcMap, I want the table for that layer to be open. Found TableView (doc) and ...
0
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1answer
137 views

How to find zoom levels based on a given bounding box in srs 4326?

I need a function that outputs Zoom Level of a bounding box. for example imagine this bbox: 38.056640499272,22.412109500728,67.060546749272,36.91406262572 How can I found the level?
4
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1answer
4k views

Shapely unable to tell if polygon contains point

For an application I want to determine under which constituency a given coordinate falls. After looking at the various options, I decided upon shapely and fiona as the easiest way to implement this. ...
2
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0answers
57 views

Extract MultiValuesToPoints yields identical value for each band

I'm attempting to extract hyperspectral remote sensing data to a point featureclass using the ExtractMultiValuesToPoints ArcGIS tool. The value of each band (228 bands) should be appended as a field ...
2
votes
2answers
2k views

Creating a new feature class with python and then adding attibutes

I am having trouble adding rows to a shapefile after it has been created. I'm not sure if I need to create the shapefile in memory and add the data or creating then re-open the file. While I've ...
1
vote
2answers
282 views

Iterate Through All Combinations of Features by Selection in ArcGIS Python Script

I have question about ArcGIS and python script. There are following sample code, So I would like to change Another Field , not OIDFieldName. Please let me know how to change Another Field. import ...
-1
votes
1answer
159 views

ArcGIS python itertools.combinations [duplicate]

There is following sample code combination 5C2. I want to create all combinations 5C1 , 5C3 , 5C4 and 5C5. list = [ 0,1,2,3,4 ] 5C1 means (0),(1),(2),(3),(4),(5) 5C2 means ...
5
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4answers
2k views

Matching GPS tracks

I'm looking for a proper way to process multiple GPS tracks (so time ordered list of lat/lon points) and match/classify that segments, that are covered by multiple tracks: So it's not about ...
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0answers
99 views

Python script does not work for a LGA with space [closed]

Thanks! I got my script working now with replace gp.AddMessage() instead of print when running the script in ArcMap and replace the quote with blank as well since Python would include the quotation ...
0
votes
1answer
112 views

osm_id in a shapefile vs. the uid and id attributes in an OSM file

I'm parsing an OSM file using the Python package osmread. The entities parsed have the following attributes id, version, changeset, timestamp, uid, and tags. On the other hand, I have a shapefile, ...
10
votes
5answers
722 views

How to improve performance when using ArcGIS cursors in Python with big tables?

I have a pretty big point feature class in a file geodatabase (~4 000 000 records). This is a regular grid of points with a 100m resolution. I need to perform a kind of generalization on this layer. ...
2
votes
3answers
459 views

How to prevent ArcGIS SOC from locking Oracle tables?

I have a python geoprocessing that performs CRUD operations on feature classes and oracle tables. Sometimes, when handling Oracle tables, ArcGIS SOC gets hung and locks the Oracle table. I need then ...
1
vote
1answer
117 views

How to read the count of the cells with data with non “no-data” values ,in QGis?

How to read the count of the cells with data with non "no-data" values ,in QGis
3
votes
1answer
1k views

Read and Export OSM Road Data as a Network of Road Segments [Adjacency Matrices]

I wish to extract from an OSM file a road network, and export it as an array (adjacency matrix) where the nodes are the road intersections and the edges represent the road segments. I don't want to ...
2
votes
1answer
821 views

How to build SQL Expressions in ArcGIS 10.1 Python script tool dialog?

I've made a python tool that requires the user to establish which state to select within an input's table (the "Prepared Footprint"). However, once the user drops in the layer and tries to write the ...
3
votes
2answers
2k views

Set feature attribute by name via QGIS python api

I try to set feature attributes by attribute name with this code pr = layer.dataProvider() pr.addAttributes([QgsField("test", QVariant.Int)]) layer.updateFields() for feature in layer.getFeatures(): ...
7
votes
2answers
306 views

Finding specific pixel values ​​in ArcGIS using Python

I have a raster file containing some integer values. I need to find all pixels whose values are not defined in list like this one: l = [1,2,4,8,16,32,64,128]. Is there any easy way to solve that ...
1
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1answer
13k views

How to fix Qtcore4.dll can't find procedure entry point? [duplicate]

Possible Duplicate: How to fix QGIS error “Entry Point could not be located”? I am working with QGIS, python2.5 and pyqt4 for py2.5. My system variables are as follows: ...
1
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2answers
163 views

SUDS (SOAP) from the Python console in QGIS

I´m trying to install a SOAP API called SUDS, on a Windows 7 OS, to be able to run SOAP from the QGIS Python console and pyQGIS/Python scripts. The only Python I have installed is the one comming ...
2
votes
2answers
329 views

Can I use the LEFT (string) operator in ExecuteSQL()?

In QGIS I can use the LEFT operator on a dataset like this: LEFT( "Name2",3) ='031' What is the syntax for using this expression with ogr in python? Isn't this the right syntax? ...
3
votes
2answers
484 views

Using python to Raster clip the extent to be the same as the display?

I've been trying to figure this out for almost a week now. I am creating a tool which first needs the raster to be clipped out to the current display. I have tried all sorts of things. Below is the ...
2
votes
1answer
398 views

GeoDjango - return SRID of geometry in GeoQuerySet

I'm wondering if there is a function in GeoDjango which would allow me to determine the SRID of a geometry column in a GeoQuerySet. I know I could do it with a raw SQL query (I'm using PostGIS) but I ...
6
votes
1answer
1k views

Subsetting GeoTIFF with Python

I'm sub-setting a GeoTIFF with the GDAL Python binding and numpy. Essentially, I am providing a central location (coordinates of a flux tower) from which I produce a subsetted image. I then want to ...
1
vote
1answer
1k views

Convert polygons in shape file to a numpy array?

I have a shape file containing a number of polygons and all attributes being text. I'm trying to import the polygons into numpy as an array where each polygon is represented as unique values. I ...
0
votes
3answers
621 views

Is it possible to use GDAL without admin rights?

I am trying to do some image analysis in Python but am unable to install GDAL due to limited rights. I have attempted copying some of the files and folders into my python folder but am constantly ...
1
vote
1answer
188 views

QGIS Python Composer Attribute Table has no content

I post 2 Month ago the same question. So I try it a second time with more code. My Problem still is that I add at the composer a attribute table and in this table there is no content. My Code: ...
2
votes
1answer
1k views

How to use PyQGIS ( Python QGIS API ) to open/close Update Drawing Order checkbox in QGIS2's Layers (Legend Interface)

Thanks qgis 2, the Legend Interface (layers dockwidget) now has Update Drawing Order check box on right-click mouse context menu. I think this feature can let user temporally closes rendering, then ...
4
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1answer
1k views

raster2pgsql: Strange error when creating a table

Hi GIS Stackexchange people, When I try to load a asc file into my psql setup, I get a strange error message. I have created the sql input file via raster2pgsql -s 4236 -I -C -M gis_data.asc -F ...
8
votes
2answers
803 views

Python script to read CAD data to find polygon extents

I have Civil 3D 2012 with ArcGIS for AutoCAD 300. I want to read the extents of a polygon in the drawing. Feature Class in A4A300 = Boundaries, the CAD layer is PROP-BNDY, there is only one polygon on ...
4
votes
3answers
312 views

pyscripter out of memory

I'm running a loop that create feature classes at a geodatabase. After creating 221 datasets I get the error message "pyscripter out of memory". Is there a way to clear the physical memory of computer ...
1
vote
1answer
260 views

turn a Result object into a number

**import arcpy from arcpy import env from arcpy.sa import * import math # Check out any necessary licenses arcpy.CheckOutExtension("spatial") # OverwriteOutput arcpy.env.overwriteOutput = True ...
5
votes
1answer
466 views

Python libraries for correlating Photo to GPX file?

Can anyone recommend a Python library(s) that can geotag a photograph with the lat/long coordinates by correlating the timestamp of the photograph to the timestamp of a waypoint within a GPX file? I ...
5
votes
2answers
745 views

Download data via a ftp server using polygon features

The attached script loops through the features of a polygon featureclass and uses that attribute information to download particular files via a ftp server. The script works great for downloading ...
0
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0answers
80 views

Best way to group datasets by country/region

I 'm using ArcGIS 10.0 and have a folder with misc GIS datasets from all over the world. I wrote a script that finds all of these datasets and writes them to a .csv file, but I also want to identify ...
1
vote
2answers
568 views

Efficient way to store multiple values of an x,y location in Python?

I am trying to read values from a stack of images and store them in a structure that will allow for easy readability. My current idea is to create a loop for x in width: for y in length: ...
2
votes
1answer
358 views

How to use Python console under QGIS 2 with gdal module?

I am trying to move my plugin from QGIS 1.8 to QGIS2.0. However, the gdal module cannot use under QGIS2.0. I try to use Python console, typing: import gdal #it's OK gdal.GetDriverByName( ...
3
votes
1answer
522 views

Serialize python list containing geometry

In simple case if list doesn't contains geometry all works fine: result = [dict(f.fields, id=f.id, label=f.label) for f in features] json.dumps(result) But if result list contains geometry ...
3
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2answers
245 views

How To Determine Percent of Matched Data?

In my attribute table, I have 2 columns with qualitative (categorical) data. Both of them are from different sources so I am trying to find the percent of matched data from these 2 columns. I created ...
3
votes
1answer
122 views

How to find lowest value that is not null using Python in ArcGIS for Desktop?

I have four fields in my table, (A,B,C,D). The field type is double with some fields being NULL. I used min(A,B,C,D) to return the smallest value and it works well if there are no NULL value in any of ...
4
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3answers
481 views

How to find/replace element in field with Field Calculator

I just want to perform the following operation done in Matlab into the Field Calculator using Python: p(p==0) = 0.001 ; p(p == 1) = 0.999; tVar = .5*log(p ./ (1 - p)) the operation consists of a ...
0
votes
1answer
188 views

OS X Python vs QGIS Python

I'm wondering why after I updated to Python 2.7.6 on my OS X 10.9 Mac, QGIS Python console says that it is still running the old 2.7.5 version. This is not affecting my work but I'm curious about why ...
1
vote
1answer
128 views

How to build and pass remap for floating point raster without getting Reclassify ERROR 010255?

I am receiving the following message when executing my python script: ERROR 010255: String remap must be used with a string field. My input raster is floating point and I would like to ...