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

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4
votes
1answer
280 views

How to add points to LAS copy using liblas?

I am trying to make a copy of a LAS file while inserting new points using python liblas module. The code below creates the copy and adds the points, but for some reason the added points are not in ...
-1
votes
1answer
62 views

Help interpreting open text file [closed]

I have an existing Arcpy script written by others that I need help interpreting. The script reads records from a feature class and loops through and writes them to a log file. Here is the section I ...
2
votes
1answer
240 views

Arcpy.GetRasterProperties_management values do not match values found via ArcCatalog or ArcView

I am using Arcpy to extract the mean and standard deviation values of tiff Landsat satellite images and I get very high values. Values in the thousands rather than in the low hundreds! If I look at ...
3
votes
1answer
1k views

How to label vector features programmatically?

I am using python for QGIS 2.0.1 and I have a vector layer of points representing the positions of state labels. I want to display the 'state abbreviation' attribute on the corresponding point for ...
4
votes
2answers
2k views

Programmatically load composer from template and generate atlas using pyQgis

I Am trying to build a plugin to load a print composer from file, generate an atlas and export to image. So far I have been successful in loading the template and exporting it to image. I have been ...
3
votes
1answer
325 views

How to use SAGA ShapesToGrid via Processing in a Python plugin?

I run these lines in my code: vectorlayer_vector = ftools_utils.getVectorLayerByName(inputLayer) Elevation = self.lineAttrib.currentText() cellSize = int(self.linePix.value()) outPath = ...
1
vote
1answer
244 views

Automatically determine polygon overlap 'islands'

I have a shapefile with many polygons. Some partly overlap with each other, some are not overlapping. I'm considering a polygon to be overlapping given a minimum area of overlap. 'Islands' of partly ...
3
votes
0answers
255 views

Accessing existing instance of qgis from stand-alone python script

For my own data analysis pipeline, I am running a split screen setup with iPython notebooks on one side, generating variables from source data, pushing them to a csv file which qgis then reads/joins ...
2
votes
2answers
585 views

Error when looping Polygon to Raster with python through different fields ArcGIS 10

This is the first time I have posted a question on here so please have some patience! I've been trying to create a python script to loop through numerous shapefiles converting various fields to raster ...
1
vote
1answer
343 views

Joining table data to features in QGIS?

I am trying to make a map using QGIS but I cannot join table data to features in QGIS. In ArcGIS for Desktop you just open the folder and then join the tabular table with the spatial data table. ...
7
votes
1answer
2k views

How to automatically generate useful scales for data driven pages in ArcGIS desktop

I have been tasked with creating several hundred maps of properties that intersect a long pipeline. The maps will zoom to the part of the property which shows the intersection. The lengths of ...
2
votes
1answer
146 views

Why is arcpy.mapping.ExportToPDF losing layer symbology?

When exporting a map it does not export the symbology within the data frame. I am using the code snippet below. >>> myMap = arcpy.mapping.MapDocument("C:/USERS/NISUSER/DESKTOP/mxd_map.mxd") ...
3
votes
1answer
760 views

Changing attribute and/or text values in Esri metadata using Python

I'm new both to this forum and Python, and I'm having trouble tracking down a solution to my problem. I'm hoping someone can offer some process-improvement advice and/or code to help get my metadata ...
2
votes
2answers
632 views

Why use “ from arcpy.sa import * ”

Previously on the following post: How to get an extent for Raster using python A user edited the original Python script by adding the following code: from arcpy.sa import * Why did he do this and ...
1
vote
1answer
275 views

Help with field calculator in Python script

I am getting a syntax error in my script but I know from testing it in ArcMap attribute table, the syntax is fine. Anyone have any idea why this code doesn't work? I see that a search cursor has been ...
3
votes
4answers
1k views

How to find and apply reprojection parameters?

I have a data set in one projection, and a shapefile in another, and I am trying to combine the two. I am using Python. I apologize for posting a "help me transform coordinates" question on this site ...
0
votes
1answer
114 views

Apply lyr file to Arcpy

I am new to ArcPy, and don't know how to assign different layers to the same lyr file. The layers have "pol" in common. Replacement is a single layer, and so must be walked through the entire ...
10
votes
1answer
1k views

Import GRASS and SAGA modules to python script

I'm new at this. I am "building" a python plugin for qgis and I want to import modules from GRASS and SAGA but I don't understand how to do it. The plugin I want to import is Kriging interpolation ...
1
vote
2answers
182 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 ...
0
votes
1answer
290 views

How to read shapefile of road segments into Python data structure to get begin and end point coordinates? [duplicate]

How can I take a shape file that has road segments and read it into a data structure in python that I can use to get begin and end points with? For example x, y to x2, y2. It's not a large shape ...
1
vote
1answer
269 views

Set Grass Region in Python grass.script

How can I set the Grass Region in Python without already having a map in the Mapset? Basically I am looking for the equivalent to this window Currently I am only able to extent an existing region, ...
4
votes
1answer
300 views

Why does arcpy.ListFields list GUID field as SmallInteger?

I want to get a list of all GUID fields in a feature class, but it seems that arcpy.ListFields is listing my GUID field as a SmallInteger. What am I doing wrong? global_id_fieldnames = [f.name for f ...
2
votes
0answers
397 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 ...
2
votes
3answers
129 views

How to analyze and combine overlaping elevation maps into one?

I have 30 overlapping maps that contain tree density heights (measures between 1-100%) of a large area, and I need to get the highest point by pixel and create a new map with all these highest points ...
2
votes
0answers
799 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 ...
18
votes
3answers
387 views

Python literature relevant to QGIS

Python for ArcGIS is a book that I have been looking at. Does anyone know if this would be applicable in QGIS? I am not looking to write application/plugins, simply get better at understanding ...
1
vote
1answer
923 views

Linux Client for OpenGTS server

I've installed an OpenGTS server and successfully linked it with the GPS2OpenGTS_Pro application for android. The buses I'm tracking offer 3G with a wireless AP, however whenever the bus stops, the ...
2
votes
3answers
1k views

Using python elif syntax in Field Calculator to reclassify a range of values from a different field and populate a new field

I'm trying to use the Field Calculator with a python elif statement to reclassify values from a different field and populate a new field, and while I'm not getting an error message of any kind, I'm ...
1
vote
3answers
1k views

ArcGIS 10.1 crashes on use of python window

When I open the python window in either ArcMap or ArcCatalog (ArcGIS 10.1) as soon as I press a key it freezes the entire program and it crashes. It doesn't produce any warning, error, or pop up with ...
0
votes
1answer
74 views

Setting up Raster Calculater for QGIS Python Console: ImportError?

I'm trying to follow the instructions here How to evaluate raster calculator expressions from the console? to set up the python console to to use the raster calculator. I tried: from qgis.analysis ...
2
votes
1answer
273 views

Does spherical equilateral triangle T contain point P?

I am working on a Python script to: compute the vertex coordinates of a geodesic sphere/icosahedron, project the triangles onto a sphere, then find which spherical triangle contains an arbitrary ...
1
vote
0answers
36 views

Map algebra from QGIS python console? [duplicate]

What command do I use to do map algebra on rasters from the QGIS python console?
11
votes
1answer
855 views

PyQGIS file lock release

I was wondering what triggers the release of file locks in pyQGIS? I am trying to delete a few data sources (used temporarily) by calling QgsVectorFileWriter.deleteShapeFile, but I have to quit QGIS ...
2
votes
2answers
64 views

Prevent ArcGIS saving shapefiles into workspace

How can I stop ArcGIS creating output shapefiles as results of various tools? I have got a script returning a certain value. However in order to get this value a have to use several functions such as ...
3
votes
2answers
1k views

Why does ArcPy Excel To Table give AttributeError: 'module' object has no attribute? [closed]

I'm trying to import an excel workbook using arcpy. ExcelToTable, but I get the following traceback: ERROR updateParameters Execution Error: Runtime error Traceback (most recent call last): File ...
3
votes
0answers
212 views

Generate tiles using GPU

I was wondering if anyone has tried already to utilise the GPU in tile generation? I have a quite big dataset so tile generation takes a while (especially on high zoom levels) even on a quite high ...
5
votes
1answer
2k views

How to check if feature class or table contains field with specific name before adding it?

Im trying to write a script that finds out if the shapefile has a specific field and if not to add the field. I get it to show me the field, but the loop goes through each field, so it would create a ...
2
votes
2answers
49 views

Assigning ID to features with similar attributes

I have a polygon feature with three attribute columns. The values in each of the attribute columns are number coded. I want to generate an ID (fourth column) for the unique combination of the values ...
0
votes
1answer
396 views

Why do Shapefiles and GeoJSON behave differently in GDAL Python?

I have a test.shp. I loop over the file, buffer the features, and write the buffers to a new file. I tested writing the buffers to a Shapefile and to a GeoJSON. If I try to use the new buffer layer ...
1
vote
0answers
391 views

Locating the centroid (center of mass) of spherical polygons

I'm trying to work out how best to locate the centroid of an arbitrary shape draped over a unit sphere, with the input being ordered (clockwise or anti-cw) vertices for the shape boundary. The density ...
7
votes
1answer
481 views

Python3 libraries for GIS analysis

I am trying to do some spatial data analysis in Python 3 now, and I was wondering what the best libraries are for GIS in Python 3. The Fiona library was developed with Python 3.3 but the Python 3+ ...
3
votes
1answer
758 views

pyspatialite: Connot insert geometry

I'd like to insert a row with a point geometry with pyspatialite. The sql looks like this: insert into eqdata(origin_time, url, mag, lat, lon, depth, m_a, region, mt, the_geom) ...
0
votes
1answer
800 views

How to add raster data to Table of Contents using python?

I can easily add shapefiles to the Table of Contents in Arcmap using the following codes: mxd = arcpy.mapping.MapDocument("current") df = arcpy.mapping.ListDataFrames(mxd, "Layers")[0] path = ...
3
votes
1answer
128 views

Any case when one must use older ArcPy cursors (not da module based)?

I was using the arcpy.da cursors in ArcGIS 10.2 to iterate for quite some time now yet didn't use "classic" cursors that became available in 10.0 a single time. Is there any situation where one would ...
2
votes
1answer
948 views

How to create a symbol with graduated marker size and line width in pyQGIS?

I am using QGIS + pyQGIS + Python. Layer geometry is line. Each line has a magnitude and a direction (from 1st node to 2nd node). What exactly I want to perform is "graduated width marker symbology ...
0
votes
2answers
793 views

Find longitude for point between two coordinates with pyproj?

I've written a function to get the longitude of a point of known latitude between two known points (might not be working correctly yet), but I feel like there must be a better way of using pyproj to ...
2
votes
3answers
3k views

Is it possible to open rasters as array in NumPy without using another library?

I know that it is possible to open a raster as an array in NumPy using GDAL, but I want to skip GDAL and use NumPy only, as it is cooler handling rasters with NumPy as matrices. There is a similar ...
0
votes
0answers
36 views

qgis build under ubuntu 12.04, but all the python plugins are not there

All the .so plugin show correctly, only the python plugin do not. I am confused and do not know how to fix this. I think there must be some python problem . The build process is successful.
2
votes
1answer
346 views

How to smoothly join two rectangles

I am looking for the Math and steps involved not using a tool. We have PostGIS but its an old version so we are working with the data in Python. Given three coordinates: -107.37, 52.46 -103.24, ...
3
votes
1answer
2k views

layer.visible command not working in arcpy.mapping module

I am using the arcpy.mapping module for the first time, and the lyr.visible command is not working as it should (or I am not using it as I should). I have a list that contains the the layer names of ...