zmapio 0.3

要安装：

$ pip install zmapio

zmapio的基本用法

importmatplotlib.pyplotaspltimportnumpyasnpfromzmapioimportZMAPGrid

%matplotlibinline

读取zmap文件：

z_file=ZMAPGrid('./examples/NSLCU.dat')

访问评论标题：

forcinz_file.comments:print(c)

Landmark Zmap grid file name:   .DATANSLCU.dat
Created/converted by Oasis Montaj, Geosoft Inc.

绘制网格数据：

z_file.plot()

行和列的计数：

z_file.no_cols,z_file.no_rows

(435, 208)

Z值形状：

z_file.z_values.shape

(208, 435)

导出到csv文件：

z_file.to_csv('./output/output.csv')

head ./output/output.csv

-630000.0,2621000.0,-16481.9570313
-630000.0,2618000.0,-16283.9033203
-630000.0,2615000.0,-16081.5751953
-630000.0,2612000.0,-15856.7861328
-630000.0,2609000.0,-15583.7167969
-630000.0,2606000.0,-15255.734375
-630000.0,2603000.0,-14869.3769531
-630000.0,2600000.0,-14426.1513672
-630000.0,2597000.0,-13915.8769531
-630000.0,2594000.0,-13340.4677734

导出到WKT文件：

z_file.to_wkt('./output/output.wkt')

导出到geojson文件：

z_file.to_geojson('./output/output.json')

导出到熊猫数据帧：

df=z_file.to_dataframe()

df.Z.describe()

count    90480.000000
mean     -5244.434235
std       4692.845490
min     -16691.371094
25%     -10250.590088
50%      -4003.433105
75%      -1320.896881
max       2084.417969
Name: Z, dtype: float64

以每行3个节点的格式编写新的zmap文件：

z_file.write('./output/test.zmap',nodes_per_line=3)

head ./output/test.zmap

! Landmark Zmap grid file name:   .DATANSLCU.dat
! Created/converted by Oasis Montaj, Geosoft Inc.
@.DATANSLCU.dat, GRID, 3
20, 1e+30, , 7, 1
208, 435, -630000.0, 672000.0, 2000000.0, 2621000.0
0.0, 0.0, 0.0
@
      -16481.9570313      -16283.9033203      -16081.5751953
      -15856.7861328      -15583.7167969      -15255.7343750
      -14869.3769531      -14426.1513672      -13915.8769531

从字符串创建zmap对象：

z_text="""
!
! File created by DMBTools2.GridFileFormats.ZmapPlusFile
!
@GRID FILE, GRID, 4
20, -9999.0000000, , 7, 1
6, 4, 0, 200, 0, 300
0.0, 0.0, 0.0
@
       -9999.0000000       -9999.0000000           3.0000000          32.0000000
          88.0000000          13.0000000
       -9999.0000000          20.0000000           8.0000000          42.0000000
          75.0000000           5.0000000
           5.0000000         100.0000000          35.0000000          50.0000000
          27.0000000           1.0000000
           2.0000000          36.0000000          10.0000000           6.0000000
           9.0000000       -9999.0000000
"""z_t=ZMAPGrid(z_text)z_t.plot()

使用matplotlib添加ColorBar和ColorMap:

z_obj=ZMAPGrid('./examples/NStopo.dat')fig=plt.figure(figsize=(12,6))z_obj.plot(cmap='jet')plt.colorbar()

从具有形状的2d numpy数组创建新的zmap对象（无列， 没有行：

z_val=z_obj.z_values.swapaxes(0,1)print('Z-values shape: ',z_val.shape)new_zgrid=ZMAPGrid(z_values=z_val,min_x=-630000.0000,max_x=672000.0000,min_y=2000000.0000,max_y=2621000.0000)

Z-values shape:  (435, 208)

new_zgrid.plot(cmap='gist_earth')

自定义写入zmap文件：

new_zgrid.comments=['this is','a test']new_zgrid.nodes_per_line=4new_zgrid.field_width=15new_zgrid.decimal_places=3new_zgrid.name='test'new_zgrid.write('./output/new_z.dat')

head ./output/new_z.dat

!this is
!a test
@test, GRID, 4
15, 1e+30, , 3, 1
208, 435, -630000.0, 672000.0, 2000000.0, 2621000.0
0.0, 0.0, 0.0
@
        -67.214        -67.570        -67.147        -69.081
        -73.181        -74.308        -72.766        -72.034
        -70.514        -68.555        -66.195        -62.776

参考文献

• https://lists.osgeo.org/pipermail/gdal-dev/2011-June/029173.html
• https://gist.github.com/wassname/526d5fde3f3cbeb67da8
• Saltus，R.W.和Bird，K.J.，2003年。阿拉斯加北坡及邻近北极地区数字深度层位汇编。美国地质调查局数据发布：https://doi.org/10.3133/ofr03230