PROSAGA码农传奇-MapInfo-如何使用免费工具将ESRI或MapInfo GIS数据转换为图像？ [关闭]

0# 雨儿 | 2019-08-31 10-32

1# 永远的记忆 | 2019-08-31 10-32

<div class =“post-text”itemprop =“text”>
  <P>
    我假设你想为每个选民分别形象？如果是这样，我会采用以下方法使用python：
  </p>
  <H1>
    使用GDAL / OGR读取几何体：
  </H1>
  <P>
    安装
    <a href="http://trac.osgeo.org/gdal/wiki/DownloadingGdalBinaries" rel="nofollow noreferrer">
      GDAL / OGR工具
    </A>
     和他们的
    <a href="http://pypi.python.org/pypi/GDAL/" rel="nofollow noreferrer">
      python绑定
    </A>
    。下载选区边界的ESRI shapefile。确保您可以使用OGR读取多边形几何：
  </p>
   <pre>
    <code>
      import sys
import ogr

ds = ogr.Open( "/path/to/boundary/file.shp" )
if ds is None:
    print "Open failed.\n"
    sys.exit( 1 )

lyr = ds.GetLayer(0)

lyr.ResetReading()

feat = lyr.GetNextFeature()
while feat is not None:
    geom = feat.GetGeometryRef()
    if geom is None or geom.GetGeometryType() != ogr.wkbPolygon:
        print "no poly geometry\n"

feat = lyr.GetNextFeature()

ds.Destroy()

</code>
  </pre>
  <H1>
    使用matplotlib通过匀称的descartes输出几何体
  </H1>
  <P>
    安装
    <a href="http://matplotlib.sourceforge.net/" rel="nofollow noreferrer">
      matplotlib
    </A>
    ，
    <a href="http://trac.gispython.org/lab/wiki/Shapely" rel="nofollow noreferrer">
      身材匀称
    </A>
     和
    <a href="http://pypi.python.org/pypi/descartes" rel="nofollow noreferrer">
      笛卡尔
    </A>
    。修改上面的脚本，通过shapely和descartes将每个多边形加载到matplob中：
  </p>
   <pre>
    <code>
      import sys
import ogr
from shapely.wkb import loads
from descartes import PolygonPatch
from matplotlib import pyplot

ds = ogr.Open( "/path/to/boundary/file.shp" )
if ds is None:
    print "Open failed.\n"
    sys.exit( 1 )

lyr = ds.GetLayer(0)

lyr.ResetReading()

feat = lyr.GetNextFeature()
while feat is not None:
    geom = feat.GetGeometryRef()
    if geom is None or geom.GetGeometryType() != ogr.wkbPolygon:
        print "no poly geometry\n"
    else:
      # create matplotlib figure:
      fig = pyplot.figure(1, figsize = [10,10], dpi = 300)   #create 10x10 figure
      ax = fig.addsubplot(111)    #Add the map frame (single plot)

# add polygon:
      patch = PolygonPatch(loads(feature.GetGeometryRef().ExportToWkb()), plus colour and line considerations)
      ax.addpatch(patch)   # simply add the patch to the subplot

# set plot vars
      ax.set_xlim(get xmin and xmax values from data)
      ax.set_ylim(get ymin and ymax values from data)
      ax.set_aspect(1)

# save as image
      pyplot.savefig('somefile.png', some arguments you like)露

feat = lyr.GetNextFeature()

ds.Destroy()

</code>
  </pre>
  <P>
    显然你需要稍微解决这个问题才能得到你想要的结果，但一般的方法应该是合理的。
  </p>
</DIV>

2# 记忆短浅♡思念不变 | 2019-08-31 10-32