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

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115 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 ...
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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. ...
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263 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. ...
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158 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 ...
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472 views

Decompress a LZW-compressed GeoTIFF

I have a LZW-compressed GeoTIFF file and would like to split it into several smaller regional files and change the format to png. I tried to do the spliting with gdal_translate -srcwin. I only get a ...
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123 views

Compare line with next line in attribute table shapefile

I am making a python code for ArcGis 9.3. The aim is to compare the value of my field "ID_BV" at line l with value of field "ID_BV" at line l+ 1. And depending of the test answer i populate another ...
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484 views

Editing QGIS point layer: retrieve attributes of intersecting line layer

I'm creating a custom editing form using QGIS 2.0 and would like to modify the mouse event when creating a point. I've gotten a start by reading this thread: How to programatically check for a mouse ...
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243 views

Getting “Segmentation fault: 11” with ogr in Python

This is the code I'm trying to run: In [1]: from osgeo import ogr In [2]: datasource = ogr.Open('testdata.shp') In [3]: datasource.GetLayerCount() Out[3]: 1 In [4]: layer = datasource....
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164 views

How to detect broken hyperlinks with arcpy?

I have zero experience with python but am trying to search for broken hyperlinks in a large gdb (temporarily converted to a shapefile)- Used code from a previous question (Hyperlink broken path - ...
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87 views

Identify different networks inside a line shapefile

I'm dealing with a quite big line shapefile containing road tracks. The roads are connected to each other, creating distinct networks. These networks are independent and they are not connected to each ...
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109 views

QGIS: rotatable markers with offset from point

Im wondering, if its possible (in QGIS), to set a rotatable marker with offset from point, like in my example below. Any suggestion?
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216 views

How to display images as cross sections in 3d

I want to display a base map and several vertical cross sections in 3D. The base map image is easy to rectify as a geotiff. How can I also display the cross sections? The cross sections are at ...
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76 views

Using the geocode function with cursors

How do I use a cursor with a geocodeaddress function? I want to be able to: 1) read from a table 2) only geocode addresses(from table1) whose street number is not 0 using a cursor 3) then update a ...
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499 views

Zonal Statistics using Gdal and Python

I recently came across a loop_zonal_stats function by @ustroetz found here: Issue Trying to create Zonal Statistics using Gdal and Python.. I am using a (single) polygon shapefile and a raster file to ...
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0answers
51 views

How to Complete ModelBuilder Process Quicker?

I've built a script tool in ArcGIS's ModelBuilder to collect parameters from the user and use them as arguments for another python script. The output of this script is a text file. The only GIS ...
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134 views

Write raster with its attribute table and symbology

I am classifying lots of rasters and I'd like to automate the legend creation and symbology displaying for easy manipulation. Here is the kind of raster I'm dealing with: library(raster) r <- ...
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58 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 ...
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537 views

How Can i create a Vector layer from selected features qgis

In my qgis plugin i select dynamically features from a Vector layer. and currently i create a new layer from selection on combining all feature into a new feature: theField = QgsField self.theString =...
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696 views

Calculating area with python qgis

I am a little stumped with determining the area of polygons in the python console. I want the output to be in meters^2, so using: qgis.utils.iface.mapCanvas().setMapUnits(0) qgis.utils.iface....
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451 views

Editing of vector layer programmatically with QGIS

I'm trying to edit vector layer using Python console and have couple of questions. Why this approach doesn't work and I have to use canvas.refresh? If I will use this code not in python console but in ...
2
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0answers
403 views

Is it possible to get field type information from FieldInfo object in ArcPy?

I'm looking at the FieldInfo object documentation for ArcGIS 10.2 and am not seeing access for field type (e.g. short, string, double). Is it possible to get field type information from the ...
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815 views

How To Export Selected Data Driven Pages to PDF?

I have a map book with data driven pages that shows the fire boundaries, roads, etc for our fire rescue department. I want to automate the process of creating individual mini map books for each fire ...
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291 views

How can I create random concave polygons for test purposes?

In the context of generating random test data using QGIS (in a shapefile): I can generate random, continuous (adjacent) polygons by first creating n random points using ftools and then generating a ...
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534 views

Finding coordinates from a nested grid as a numpy array

So this is a pretty basic question, but I'm trying to figure it out. I've written a script that allows a user to read in a raster and provide a cell resolution, and outputs the amount of cells ...
2
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158 views

Python scaling issues and possible subprocess conflicts?

I have always found such great analytical and programming expertise on StackExchange in the past that I hope you can help me. Background: I have a project that involves spatially joining and ...
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142 views

How to join attributes by location with command line

I would like to joint the attributes of 2 shapefiles by location but with a command line (linux). This feature is easy in QGIS but it is VERY slow. Is there a way of doing this with ogr or pyqgis ? ...
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208 views

Modifying Raster Layer with Python Console

Forgive me if this has been asked somewhere else. I am looking for a way to edit a raster file which has already been loaded into QGIS through the python console (i.e. I would like to edit the raster ...
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196 views

Python Script within ArcMap running GME Command passes a double forward slash when writing the log file

I thought I made some serious headway there today. My script works perfectly fine when run from a Python Shell, but in ArcMap, whether the script is run from the Python Command line, or within a ...
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69 views

Loading a layer into the same position as an existing layer in QGIS

I understand that it is not possible to directly reload a shapefile layer in QGIS using the reload method in Python, since this method is not implemented for shapefile data providers. Thus, the ...
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470 views

PyProj/Proj4 convert geographic to projected coordinates for Geostationary Data

I am trying to convert geographic coordinates (in degrees east/north lon lat) to projected coordinates in meters for geostationary full disc data (GVAR Goes East data from CLASS). To do this, I tried ...
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496 views

Why does ArcGIS Resample tool change cell size and numbers of columns and rows?

I am working with images of oxygen distribution within individual plant root systems submerged in water. The program I use to acquire these images, LookatRGB, splits the green band in half and makes ...
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308 views

Qgis libqgispython.so failed to load

I am using Qgis 1.8 and Python (on Ubuntu 12.10) for a couple of month now, but today i got suddenly the error Couldn't load Python support library: Cannot load library /usr/lib/qgispython: (/usr/lib/...
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449 views

3D features (Polyline, Polygon) intersection library

For my research I am looking for a (python) library to get the intersection of some 3D features. The features can be Polygons or Polylines. Mostly I need to intersect a plane with my features and get ...
2
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0answers
134 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, ...
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0answers
153 views

returning exceptions to user via AGS REST

I've got a python script that I run as a standalone and as a gp service in AGS (moving to 10.1 now...). For the standalone execution, I'm throwing a custom exception if there is no data found based on ...
2
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0answers
69 views

Is there any way to symbolize a user-supplied input parameter in ModelBuilder?

I have a model built in ESRI ModelBuilder that is run from its tool dialog, where the user supplies the input feature layer that then gets processed in the model. I need the input feature layer to ...
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701 views

Use GDAL/Python to add rasters (tiff) to an ESRI File Geodatabase

I'm using GDAL python to create a bunch of tiff files from a netcdf file. def modelout_to_geotif(netcdfile, outdir, VarName): """ Given the path to the netcdf output, produces geotiffs for ...
2
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0answers
228 views

How to programmatically change an SVG symbol in the Vector Layer?

I'm trying to change the symbol used in a layer via Python. I've been able to tunnel through a vector layer to the symbol layer, but I don't know how to change the symbol it's using. I'd like to ...
2
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0answers
115 views

Custom python datasource to QGIS

I'm working on a homebrew spatial feature data format, and using Python to write it's API. It occoured to me that use some tool like QGIS to display my data would be very nice to have, for debug/test ...
2
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0answers
159 views

Python script to create a point on a line with attribute data

I have a line feature class with 2 lines (Engineering and Continuous Station series) co-incident on each other. I have created a toolbar(ArcGIS Desktop add-in 10.1) with 3 tools on it, add control ...
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446 views

Multiple ring buffer on point-shape error

I need to calculate multiple ring-buffers, but every time I try, arcgis produces a failure: Executing (Multiple Ring Buffer): MultipleRingBuffer Y:\GIS\RDY\clip\sn_clip.shp Y:\GIS\RDY\sn_clip_ring....
2
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0answers
344 views

Running a new iteration for each column of a dataset in ArcGIS

I'm pretty new to Modelbuilding, having just been turned onto it about a week ago on here. So my problem is, I currently have a dataset of habitats that change through time (from Immature to Mature, ...
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81 views

Arcpy: Counting number of segments where altitude rises or decreases based on DEM?

I have a DEM of Sudety mountains and linear .shp with several hiking paths. I'm trying solve one problem: How to make a script based on input DEM and input line shapes that would count number of ...
2
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0answers
437 views

problem in read_shp() to generate a networkx.DiGraph from point and line shapefiles

I tried to use the Python module networkx and specifically the read-shp () to ensure the transformation of a graph to a file sharpe but I always find this error noting that this is the first time I ...
2
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0answers
229 views

projection discrepancy with gdal (1.9) and proj4

I boiled the problem down to that python example: import sys try: from osgeo import gdal from osgeo import osr except: import gdal import osr if __name__ == '__main__': version_num = int(gdal....
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242 views

Localized Linear Histogram Match using python

I would like to use the local linear histogram match for filling the missing pixels of a Landsat 7 image with another older image (SLC Gap-Filled Products). Do you have any idea how can I do it by ...
2
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0answers
80 views

Removing FID as an option from ArcGIS Tool Validation Parameters

I am currently building a script tool which requires the user to select a sorting field from a list (built using a dependency on the featureclass). This Element is working fine, but I would like to ...
2
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0answers
61 views

Is there a way to distinguish between digitized and pasted features?

Is there a way to tell if an added feature in QGIS is in fact a newly digitized one or a pasted feature? I think QGIS is treating both cases in the same way, emitting the same signal: ...
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0answers
147 views

Convert geojson labels MBR to MapInfo text object

Im using Dymo (https://github.com/migurski/Dymo/) to generate automatic point labels placement. The output of Dymo is a geojson containing MBRs of the positioned labels with the names of the labels in ...
2
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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 ...