NumPy is an extension to the Python programming language, adding support for large, multi-dimensional arrays and matrices, along with a large library of high-level mathematical functions to operate on these arrays.

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Tabulate Area using GDAL and Numpy

How could I perform a Tabulate Area using GDAL and Numpy? I am trying to summarize how many pixels of each class in a Landcover raster are within each polygon of a Census Blocks shapefile. I've ...
3
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0answers
318 views

Buffering a Raster with GDAL and Numpy

I am using GDAL to convert a raster dataset into a numpy.array and then using numpy to buffer the data in the raster. For example, I need to know all the regions within 100ft of a school point ...
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1answer
92 views

arcpy array: trouble with reassigning inf to 0

I've converted rasters to arrays via arcpy.RasterToNumPyArray() then divided them by 1. Some resulting values are zero and I need to reassign them after the division to zero. The array types are ...
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1answer
323 views

Problem with converting rasters to arrays and adding them to main array, then converting to raster via NumPyArrayToRaster : output is NoData values

I have a process that aims to loop through a list of rasters (testing with only 3) covert each raster to an array, add the array to an existing 'template' array, then save the final array back to a ...
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0answers
184 views

How to create multi-image single band single file geotiff?

I have a geotiff file that is single band but contains multiple subdatasets. I use gdal with numpy to open a specific subdataset and mask some of its values. Example: $ gdalinfo sample.tif ... ...
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1answer
1k views

Display a georeferenced DEM surface in 3D matplotlib

I want to use a DEM file to generate a simulated terrain surface using matplotlib. But I do not know how to georeference the raster coordinates to a given CRS. Nor do I know how to express the ...
6
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1answer
515 views

ArcGIS Desktop 10.1 SP1: how to install/use additional Python modules?

I'm currently working on a project where I have to identify geomorphological features in a digital elevation model. Since the aim is to have a single ArcGIS Toolbox integrating all processing steps in ...
6
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1answer
762 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 ...
3
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1answer
1k 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 ...
5
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2answers
738 views

Does anyone use both ArcGIS and Python(x,y)?

I'm trying to get ArcGIS 10.1 and Python(x,y) to peacefully co-exist with a unified installation of Python. Surely someone else is using both these tools... right? Pointers would be much appreciated. ...
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1answer
195 views

Problem with calculating the total cell values

aa= arcpy.RasterToNumPyArray("water_depth") sum = numpy.sum(aa) print sum -2933737 Why I am getting negative values ? In my raster there is no any negative ...
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218 views

Averaging satellite data with missing values (using Python)

I am using sea surface temperature, chlorophyll, and other data parameters as covariants in a model, and I would like to average them over a particular time period. I am currently doing this using a ...
13
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1answer
968 views

How can I utilize NumPy arrays to optimize big data geoprocessing?

I'm interested in learning how to utilize NumPy arrays to optimize geoprocessing. Much of my work involves "big data", where geoprocessing often takes days to accomplish certain tasks. Needless to ...
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3answers
1k views

Gdal Dataset.ReadAsArray() crashes Python

I am using Python 2.6.5 (32bit) with Numpy 1.3 and Gdal 1.9.1 installed on Windows 7 64bit. I am trying to read an 800 MB Imagine (.img) raster dataset into a Numpy array to do some raster algebra, ...
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1answer
132 views

keeping the coordinate system of raster files in the resulting raster file after operation with numpy

I'm trying to read as array two raster files using ReadAsArray in GDAL/python, perform some map algebra operation on it using numpy and then write the resulting raster file in GTiff format using ...
8
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2answers
1k views

How to keep spatial reference using arcpy.RasterToNumPyArray?

I am using ArcGIS 10.1, and want to create a new raster based on two preexisting rasters. The RasterToNumPyArray has a good example which I want to adapt. import arcpy import numpy myArray = ...
13
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3answers
5k views

Writing numpy array to raster file

I'm new to GIS, and I'm lost with something I feel ought to be relatively simple. I have some code that converts infrared images of Mars into thermal inertia maps, which are then stored as 2D numpy ...
2
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0answers
316 views

How do I use scipy.ndimage.gaussian_filter1d on an arbitrary axis?

I have a GDAL raster that looks like this: And I would really like to blur this raster along an arbitrary transect. I see that scipy.ndimage has a gaussian filter that allows me to blur the raster ...
9
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3answers
5k 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 ...
4
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1answer
588 views

raster algebra in python with rasters of different extents

I am trying to find out how to use GDAL & numpy modules to average a set of rasters....which are Sigma0 values from satellite passes at different times within a year. Each raster has been ...
5
votes
2answers
491 views

Adding noise to a raster

I want to add some fine-grained noise to a raster in an automated python process (i.e. I do not want to use Photoshop or GIMP). I looked at PIL, but unless I'm mistaken, it doesn't seem to have any ...
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0answers
347 views

ValueError when reading a raster band as a numpy array

Here's the problem shown in Python shell: In [32]: from osgeo import gdal In [33]: geotiff = '/Users/calvin/work/luc/proj_public/media/GLO ...
2
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1answer
495 views

Calculating beta-diversity w raster data [renamed]

Using ArcGIS 10, it is not possible to generate a raster attribute table for 32-bit float values. Instead, I have tried the RasterToNumPyArray method, which crashes since the file input raster is so ...
3
votes
2answers
602 views

PostGIS + pgRouting: Adding dummy links to a road network and performing routing analysis

I'm a beginner when it comes to postgis and pgrouting development. For a project I'm working on and a bit of the algorithm: I have a polygon layer that represents zones I have a line layer that ...