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

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682 views

ogr: how to use epsg database for RD New projection?

I'm trying to assign this EPSG projection to my newly created shapefiles using ogr. The OGR Projections Tutorial says: ...any geographic coordinate system in the EPSG database can be set by it's ...
5
votes
1answer
1k views

How to Create a raster layer from a numpy array using pyqgis?

I am working on a plugin for Qgis to calculate spatial Kernel density maps. I have all the calculations working, all I am missing is a way to turn a Numpy Array, with density values into a multiband ...
10
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2answers
338 views

Count raster value in a bounding box (spatial extent)

I have simple question: given a bounding box, how can I count the number of specific values (say, I am interested in the number of value == 1 ) in a raster in 1) arcpy, or 2) raster package in R?
6
votes
1answer
2k views

Retrieve path and file name of current qgis project in python

Is there a way to get the path and the file name of the current project from a python script? I'm currently trying to develop a python plugin for qgis and I need to create a file with a similar name ...
3
votes
3answers
264 views

How to compare a set of images with a shapefile?

I have around 150 images (rasters), each one is just a map of certain "classes", e.g. pixel value 1=forest. I also have a shapefile that consists of roughly the same area as the 150 images constitute ...
3
votes
1answer
3k views

Writing Python script to give multiple buffers of different sizes in ArcGIS for Desktop?

I want to write a loop that will cause the output to be multiple buffer shapefiles. For example, I want a circle buffer of 50ft, 100ft, 150ft, etc. Can anyone help? I'm new to this and am trying ...
4
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0answers
9k views

Create a stacked bar chart with matplotlib [closed]

I'm trying to create a stacked bar chart in python with matplotlib and I can draw my bar one up the other # -*- coding: utf-8 -*- import psycopg2 import matplotlib.pyplot as plt import numpy as np # ...
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2answers
260 views

What is the difference between Geoprocessing Map object vs. MapDocument object in Python

I have the following code: mxd["C1"] = arcpy.mapping.MapDocument(os.path.join(fRoot, filename)) mxd["C2"] = [arcpy.mapping.MapDocument(os.path.join(fRoot, filename))] C1 creates a geoprocessing Map ...
3
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2answers
1k views

Check if field value for selected features is null using ModelBuilder

My feature class contains two fields: an identifying field U_ID, and a descriptive text field DESC. This field currently has <Null> for all features. I would like to select all the features with ...
2
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1answer
2k views

Mapping x, y pixel coordinates to latitude and longitudes on the WGS84 datum

Apologies in advance for the long question, I am fairly confused at this point and I figure if I show my thought process any flaws early on in the piece can be more easily pointed out. I have a grid ...
2
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1answer
428 views

How can I use Python to save several MXDs within the same script?

I have a program (720 lines of code) that runs multiple tasks on Arcmap .mxd files. Such as update layers, update text, add layers, etc. Within my program I have multiple "mxd.save()" instances. All ...
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3answers
227 views

How can I save a column from the attribute table of a vector layer to a variable?

I am trying to write a python plugin for QGIS that can convert three vector layers into an object File for an urban climate model. Unfortunately I am stuck again with a possibly easy question: How ...
2
votes
1answer
614 views

Script for Editing TIN in Arcgis: modelbuilder works, when exported as script gives an error

Arcgis can give such a headache! I want to automate loads of small tasks, and so I need to edit empty TIN with python in order to create a full TIN. My srcript is giving errors, so I tried by hand to ...
3
votes
1answer
855 views

How to programmatically identify and rename duplicate records?

I'm trying to identify duplicate records from a field and then change these records so they become unique (eg A,B,C, or 1,2,3) and assign this to the end of the text (eg F3241 A56_A or F3241 A56_1). I'...
2
votes
0answers
459 views

How to access mysql data from python built-in console?

I'm writing a QGIS Plugin, and somewhere I want to present data from a MySQL database. It's simple data(strings,etc), not Geospatial, or vector data. I'm familiar with querying databases from python ...
3
votes
1answer
189 views

Show feature classes as a checklist in a workspace in ModelBuilder

In my model, I would like to show all the feature classes inside a file gdb as a "checklist", similar to how the tool dialog window for Make Query Table looks: So instead of the input being a table,...
5
votes
2answers
2k views

FWTools ogr2ogr in Python

I am trying to convert MapINFO tabs to ESRI Shapefiles using FW Tools. I downloaded the tools and can run the FW Tools Shell and convert no problem: ogr2ogr -f "ESRI Shapefile" E:\CABWorking\...
5
votes
2answers
1k views

Updating polygon geometry: deleting inner rings with python

I've searched, but can't find clear explanations how can I simply delete inner rings from existing polygons with python or extract outter rings and overwrite the geometry. Seems GDAL/OGR should be the ...
0
votes
1answer
722 views

zonal histogram fails to create output table when looping

Using python I'm having problems when trying to attempt a FOR LOOP with the ZonalHistogram function of ArcGIS 10.1. It works fine if I use it only for one image but it gives me this error while for ...
2
votes
1answer
1k views

How to drop ArcSDE connection using Python scripting?

I want to be able to control connections to ArcSDE via python. Here is my script so far using ESRI's example. import arcpy from arcpy import env env.workspace = r"SDEConnection" fcList = arcpy....
6
votes
1answer
482 views

Python/GDAL get unique values in discrete-valued raster

I would like to get some advice on the most efficient way to return a list of unique values of a discrete-valued raster using Python and GDAL. I had thought that the most obvious way would be to ...
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2answers
2k views

How to bypass errors in arcpy for/while loop?

I have a handy script tool that loops through a workspace and renames and copies shapefiles to a feature dataset. However, if there is a corrupted shapefile somewhere in the workspace the script ...
5
votes
2answers
2k views

Is there a way to get at C's OGRLayer.Intersection() or OGRLayer.Clip() in Python?

I am working with OGR in Python and noticed that the C libraries have useful Intersection() and Clip() functions as part of the Layer class. Is there any way to get at these functions in Python? I ...
0
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1answer
246 views

How to populate Unique ID field after sorting?

I am trying to create an new unique id field in a feature class. I already have one field called "SITE_ID_FD", but it is historical. The format of the unique value in that field isn't what our current ...
4
votes
1answer
254 views

Dropdown menu to select vector layer from current displayed layers in qgis

I'm trying to write a python plugin to create an input file for an urban climate model out of three shape files. One of the shape files contains the buildings (polygon), one the trees (point), and the ...
6
votes
3answers
2k views

How do I extract a raster's extent in python?

I am looking for an easy way to extract a raster's extent in python. Currently, I am using gdalinfo and then parsing out the corner coordinates. The problem with this approach is that gdalinfo is ...
1
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1answer
2k views

Why can't I install python-qgis on Ubuntu 12?

I am with ubuntu 12 and Qgis 1.8. I have installed QGIS and grass plugin but I can't install python plugin. How to install python plugin with dependeny in Ubuntu? ~$ sudo apt-get install python-qgis [...
2
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0answers
109 views

How to call a method when self.iface.actionSelectRectangle().trigger() is released?

In my QGIS python plugin I use "self.iface.actionSelectRectangle().trigger()" to select features. I also have a button which changes the attributes of the selected features. Is there a way instead ...
2
votes
0answers
219 views

qgis and embedded ajax (bing map)

I need to load in a docked QWebView this html: < html > < body > < iframe width="100%" height="499" frameborder="0" scrolling="no" marginheight="0" marginwidth="0" src="http://...
2
votes
1answer
356 views

Is it possible to set a layer style (e.g. set the color ramp) before loading the layer using pyQGIS?

I am implementing a tool which allows an user to calculate some statistics with some data from the registration office. My question is, can I set some layer styles using pyQGIS? The analysis part is ...
0
votes
1answer
711 views

Looping Dataframe in Python doesn't Return Expected Results

I'm creating a python addin script to be used on some mxd's I have created as templates. Each map contains 2 dataframes. I need to loop through each dataframe and do some processing on each. I set my ...
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3answers
520 views

Why do I get a no module error when I try to batch process in Arc10?

I was trying to batch reproject a set of shapefiles and I kept getting the error No OS Module As the set was relatively small I just did it individually, however I want to be able to batch process in ...
4
votes
1answer
1k views

How to split geometry collection into its items using Python and QGIS API?

I'm getting some geometries via intersecting lines by polygons (somewhat blindly - I don't really know if intersection exists and actually I don't need to know) using python and QGIS API: some_line....
6
votes
3answers
330 views

Do OSGeo4W and ArcGIS 10.0 use the same Python installation?

This question was asked several years ago at: Can ArcGIS and OSGeo4W share the same python install?, but it seems that versions have changed since then. I currently have ArcGIS 10.0 installed (not ...
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3answers
11k views

How to fully load a raster into a numpy array?

I have been trying to check my filters on DEM raster for pattern recognition and it is always resulting in missing last rows and columns(like..20). I have tried with PIL library, image load. Then with ...
3
votes
2answers
5k views

How do I use python to batch process the reprojection of a group of shapefiles?

My client would like his shapefiles reprojected and I would like to get a script that can batch process all the files located in the same folder. I am new to Python and ArcPy but am very interested. ...
1
vote
1answer
834 views

How do I find out if a given lat lon is in a KML Linear ring using shapely?

I'm a GIS basic/novice user. I have some LinearRings in a KML file that give the areas for a bunch of different regions. And then I (will) have some lat lons that I want to test to see if they're ...
3
votes
1answer
284 views

How to clip a Oracle query layer directly in a Python script?

I have a query layer directly running from ORACLE database in a MXD. I want to clip this layer with a layer being created in another MXD in a Python based tool. My question is to do this clip ...
1
vote
1answer
201 views

Qgis mapserver - Can it use plugins you use in qgis desktop?

Im thinking about developing a small python plugin for qgis which would access postgis raster database and return data via ST_AsPNG() for example. But since i need this in my wms, would it be possible ...
4
votes
1answer
755 views

Are features of new labelling tool available to control via Python API?

I am writing a plugin using Python and currently using methods that set the label similar to those seen under Layer Properties. Some of the features under the new labelling engine available on the ...
1
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0answers
242 views

Hack to change data source of a layer file in ArcGIS 9.3.1 with python?

I'm looking for a way to change the source of my layer file using python. Actually I want to do this because I need to re-use a XSL template which is defined under the tap HTML popup of the layer ...
2
votes
0answers
217 views

How can I draw an ellipse filling the dataframe with ArcPy?

I need to modify one of my template scripts to draw a circle from the centre of the (inset) data frame to the edge of the data frame. This will then be used to clip the data frame to shape. I'm using ...
0
votes
1answer
676 views

Parse attribute table value to export filename using data driven pages and arcpy.mapping

I'm trying to customize a data driven page looping statement workflow and want to set a better filename to the final export. Currently the file name uses the page index (pgIndex), but I would like it ...
13
votes
1answer
3k views

How to access feature classes in file geodatabases with Python and GDAL?

I am trying to access a vector dataset in a ESRI File Geodatabase using Python + GDAL. I have successfully compiled GDAL with the file geodatabase API. The FileGDB driver is working correctly since ...
4
votes
2answers
4k views

Create temporary files as intermediate output to be used as input in concatenation

Q_PART_I I need to merge many (MANY) tables in one unique output table by means of the arcpy.Merge_management. Anyway, I'd like to avoid the creation of tons of intermediate files as my script ...
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1answer
799 views

Python script for GRASS - executing from PHP

I wrote the following python script: #!/usr/bin/env python import os import sys gisbase = os.environ['GISBASE'] = "/usr/lib/grass64" gisdbase=os.path.join("PATH") location=LOCATION NAME mapset=...
1
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2answers
656 views

Cannot get arcpy.MosiacToNewRaster to work with list

Below I have a snippet of a much larger code that I cannot get to work and I am not sure why. It seems that I always have trouble using arcpy functions with rasters. Can anyone help me get this code ...
3
votes
1answer
94 views

> - operator and “Shape_Area” field in a geodatabase

this might be a pure python problem or a problem with arcpy. please help me out: min_area = float(GKPROZ_functions.min_of_field(out_name,"Shape_Area")) print area_max if min_area > ...
1
vote
1answer
325 views

Setting Script Tool Parameters Using Python and ArcGIS 9.3.1

Can't quite figure this out and i'm sure it's a simple fix. I have a script that utilizes the AGSSOM tool. It first stops all published services, allows for databases to be tidied up by Compressing/...
12
votes
3answers
7k views

Is there a way to use “Select by Attribute” in QGIS using a python command?

is there a way to use the function "Select by Attribute" in QGIS using a python command? In my plugin the user should enter a value via a GUI and this value should be used in a function which selects ...