gis | 易学教程

OSMNX - visualizing waterway together with footprints and ground

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问题 I am trying to plot waterway together with ground (street network/map) and footprints (buildings). My problem is that the waterways are large closed polygon areas , which means instead of plotting a nice blue river with correct thickness it plots the river all over half of the figure (and there's no water there IRL...). This is what I have in Jupyter-Lab so far (example coordinates with few roads for quick test): %matplotlib inline import matplotlib.pyplot as plt import osmnx as ox ox.config

why can't I import geopandas?

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问题 My only line of code is import geopandas and it gives me the error OSError: Could not find libspatialindex_c library file has anyone encountered this before? my script was working just fine until this error came up. **Note that rtree module not found was an issue fisrt, and upon installation I received the above error instead. 回答1: I had the same issue while working in Linux Subsystem at Windows 10 (speaking about this). What helped was installing the version for developers using apt . Namely

How to I get the coordinates of a cell in a geotif?

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问题 I have a tif with geoinformation. With gdal I can transform the raster file to an array (numpy). How can I get the coordinates for one entry in that array? 回答1: Use the affine transformation matrix, which maps pixel coordinates to world coordinates. So for example, use the affine package. (There are other ways to do the same, using simple math.) from affine import Affine fname = '/path/to/raster.tif' Here are two ways to get the affine transformation matrix, T0 . E.g., using GDAL/Python: from

Possible to render points plotted in Python with Matplotlib using a blending mode?

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问题 I'm plotting a series of overlapping points of various sizes using matplotlib in order from largest to smallest (smallest on top) but I am wondering if it is possible to configure the points to draw using a soft light blending mode so that you can see through stacks of points without using alpha blending. I'm loading my data using pandas and then plotting using the pandas plotting function (which uses matplotlib ) like this simplified example: import pandas as pd import geopandas as gpd

Possible to render points plotted in Python with Matplotlib using a blending mode?

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Possible to render points plotted in Python with Matplotlib using a blending mode?

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How do I convert a latitude/longitude pair into a PostGIS geography type?

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问题 I'm trying to load a bunch of latitude/longitude pairs into a PostGIS geography type so as to be able to query by location. In particular I have a table with float latitude and longitude columns and a geography(Point, 4326) column. I would like to do update mytable set geography = ??? The documentation appears to suggest that the following should work: update mytable set geography = ST_GeogFromText('POINT(' || latitude || ' ' || longitude || ')'); It doesn't. I don't know what it's

SuperMap iDesktop Cross 8C 开源桌面GIS下载与扩展开发

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SuperMap iDesktop Cross 8C 扩展开发的环境配置   工程源码： http://git.oschina.net/supermap/SuperMap-iDesktop-Cross Linux版Release（X64）直接下载： http://download.supermap.com.cn/SuperMapGIS/SuperMap8C/800/iDesktop/Cross/%E7%B2%BE%E7%AE%80%E7%BB%BF%E8%89%B2%E5%8C%85/SuperMap_iDesktop_Cross_8C_bin_Linux64.tar.gz Windows版Relase(X64)直接下载： http://download.supermap.com.cn/SuperMapGIS/SuperMap8C/800/iDesktop/Cross/SuperMap_iDesktop_Cross_8C_Win64.zip SuperMap iDesktop Cross 8C是基于Java的、开源的、多平台桌面GIS软件，但其内部的GIS内核Objects目前没有开源，需要商业许可。对于开发者来说，可以申请一个开发就可以使用了。SuperMap iDesktop Cross 8C目前可以运行在Linux/Windows上，可以支持飞腾

State Plane Coordinate to Latitude Longitude

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问题 I search for a C++/C# library or tool they can convert State Plane Coordinate to latitude/longitude. Thanks 回答1: You want PROJ, the Cartographic Projections Library: https://proj.org/index.html This used to be referred to as "PROJ4" but is now "PROJ". 来源： https://stackoverflow.com/questions/15237804/state-plane-coordinate-to-latitude-longitude

How to build Internal Overviews with Python gdal BuildOverviews()?

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问题 Trying to mimic the result of running gdaladdo -r average "D:\image.tif" using python gdal bindings. When I run the code below, I get an external .ovr file. How can I generate an internal overview? Am I using the correct function to mimic gdaladdo? from osgeo import gdal InputImage = r"D:\image.tif" Image = gdal.Open(InputImage,1) Image.BuildOverviews("AVERAGE", [2,4,8,16,32,64]) I've also tried Image = gdal.Open(InputImage, gdal.GA_Update) 回答1: This worked for me: Image = gdal.Open('example