NumPy is a Python module, 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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1answer
162 views

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
votes
1answer
74 views

Optimizing Python GDAL ReadAsArray

I am using the GDAL ReadAsArray method to work with raster data using numpy (specifically reclassification). As my rasters are large, I process the arrays in blocks, iterating though each block and ...
1
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1answer
193 views

gdal_proximity distance to meters

I followed the answer given in this topic for searching the distance to the nearest coastline given a lat/lon coordinate. The distance output obtained is in degree (I think) but I need the distance ...
3
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0answers
359 views

How does gdal_calc numpy operators work?

Gdal_calc manual Gdal_calc is introduced as : gdal_calc.py - Command line raster calculator with numpy syntax gdal_calc.py [-A <filename>] [--A_band] [-B...-Z filename] [other_options] ...
3
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0answers
441 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 ...
2
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0answers
64 views

arcpy RasterToNumPyArray causes shift in location of values

I am converting a couple rasters to arrays, then performing calculations on them. First step- polygon to raster. This creates a 1/0 mask that I can multiply the larger raster by. After noticing my ...
2
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0answers
491 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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0answers
418 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 ...
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0answers
39 views

Write stacks of GeoTIFF image to NetCDF by chunk size

I converted GeoTIFF image stacks to NetCDF file with writing data by Index order (layer by layer) (this was a main solution). The problem is, it writes slowly (for 25 images - 1Gb takes 90 seconds). ...
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0answers
43 views

TypeError: unsupported operand type(s) for *: 'numpy.ndarray' and 'numpy.ndarray'

I am trying to insert a value for different group of percentile eg (0- 10 percentitle) value = 1. I saw an example over here and went to try it out How do I Calculate Grouped Percentiles or Batch ...
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0answers
19 views

Read latitude/longitude to create new point grid at higher resolution

New to SE, needed to reformat my other question. Basically I'm looking at reading a CSV with longitude and latitude points (in this case housing exposure, simplified below): HUC4,Longitude,Latitude ...
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205 views

Reading, modifying and writing a geotiff with GDAL in python

I'm trying the learn the ropes of Remote Sensing image processing using Python GDAL bindings and numpy. As a first attempt, I'm reading a Landsat8 geotiff file, do a simple manipulation and write the ...
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0answers
65 views

How to accelerate my python looping process for A-star path finding on DEM surface?

I try to make an A-star Path Finding program base on tile-graph (image raster data as graph) where each pixel values represent as cost and elevation.. In my case, DEM raster data was called by using ...
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0answers
74 views

ArcPy reading a raster in a moving window?

I typically read large raster data using gdal and setting up a moving window of 256*256 pixels (for example). I recently had to do some processing using arcpy, so I did the same thing, using ...
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0answers
26 views

Raster Vector stack

I want clipped image of NDVI for a particular area. I did raster calculation for getting the image with NDVI values. After that I tried extraction function clipper. In this function we have to use two ...
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0answers
161 views

Efficient computation of path profile with Numpy and GDAL

I have numpy array with SRTM elevation data and I need calculate path profiles - vectors with elevation data from one point (transmitter) to every points of my map. Here's my current solution: def ...
1
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0answers
242 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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0answers
255 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 ...
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0answers
380 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 ...
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0answers
19 views

Using numpy.dstack() for merging two 3D arrays but losing spatial reference.

The code is as following: >>> temp = numpy.dstack((spi_negative,spi_positive)) >>> >>> temp.shape (16, 126, 294) >>> out_ras = ...
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0answers
26 views

return _NumPyArrayToRaster(*args, **kwargs) ValueError

I am trying to make an array to raster from the defined array below. However, I keep getting this error: return _NumPyArrayToRaster(*args, **kwargs)ValueError: Argument in_array: A two or three ...
0
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0answers
22 views

More pythonic approach to resolution increase of point locations

Excuse my first question being slightly more Numpy and less actual GIS, but it relates to latitude / longitude so I thought I'd give it a shot. Problem: I have a flat file with latitude and ...
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0answers
207 views

Convert Raster to Numpy Array with only Arcpy and Numpy

All the articles I'm finding including GDAL or PIL(?) which I cannot use. So I am trying to convert a raster I have to a Numpy Array with Arcpy and Numpy and then calculate some statistics on it but ...
0
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0answers
99 views

stack raster using GDAL and numpy dstack

I am testing Savitzky-Golay filter with my MODIS dataset. Currently I am testing for 10 rasters (but later on will use my whole dataset) only just to test how should I create my script. So my initial ...
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0answers
96 views

Python error in array declaration

I am getting a error as follows File "C:\Program Files (x86)\ArcGIS\Desktop10.3\ArcPy\arcpy__init__.py", line 2292, in NumPyArrayToRaster return _NumPyArrayToRaster(*args, **kwargs) ValueError: ...
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0answers
217 views

Fitting Time-series Values with a Gaussian Function

I'm trying to fit a stack of NDVI values to a Gaussian model to allow for determining dates of certain NDVI values using Python and NumPy/SciPy. I've attempted to do this with ...
0
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0answers
114 views

Import GRD and count days with temperature below zero, using python

Minimum temperature of a year is given in GRD file. I have to read that file and then calculate the frost day (less than zero degrees celcius) from it in python.
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0answers
222 views

No data appears when using gdal_calc.py but source had data values

I'm in the process of calculating topographic exposure using a mix of GDAL, grass, R and python in Windows. I need to process a very large tiff file using the following calculation: ...