added automatic flip after check, missing values, check plot

topography-tandem-x/tests.py

 from django.test import TestCase
 
 # Create your tests here.
+
+from topography_file_extraction import read_proxydata
+
+FILENAME = "greater_harz.tif"
+
+read_proxydata(FILENAME)

topography-tandem-x/topography_file_extraction.py

@@ -10,10 +10,7 @@ import numpy as np
 import os
 from toar_location_services.settings import DATA_DIR, DEBUG, USE_DUMMY_TOPOGRAPHY_TANDEM_DATA
 from django.contrib.gis.gdal import GDALRaster
-
-
-# import matplotlib.pyplot as plt
-
+import matplotlib.pyplot as plt
 
 
 def read_proxydata(filename, dummy=DEBUG and USE_DUMMY_TOPOGRAPHY_TANDEM_DATA):
@@ -41,17 +38,27 @@ def read_proxydata(filename, dummy=DEBUG and USE_DUMMY_TOPOGRAPHY_TANDEM_DATA):
     # rst.width*xscale + xmin == xmax
 
     # construct data array and lonvec, latvec
-    data = rst.bands[0].data()
+    data = rst.bands[0].data().astype(np.float)
+    nodata_value = rst.bands[0].nodata_value
+    data[data == nodata_value] = np.nan
     lonvec = np.linspace(xmin, xmax, cols)
     latvec = np.linspace(ymin, ymax, rows)
 
-    # data are flipped, therefore reverse latitudes
-    # trick from http://stackoverflow.com/questions/6771428/most-efficient-way-to-reverse-a-numpy-array
-    latvec = np.fliplr(np.atleast_2d(latvec))[0]
+    # check if data is flipped
+    lat1 = lat0 + dlat * rows
+    if lat1 < lat0:
+        lat0, lat1 = lat1, lat0
+        latvec = np.flipud(latvec)
 
     # set metadata
     boundingbox = [lon0, latvec.min(), lonvec.max(), lat0]
 
+    if DEBUG:
+        plt.contourf(lonvec, latvec, data)
+        plt.savefig('../plots/topography.png')
+        plt.close()
+
+
     #
     datainfo = {'size': (rows, cols), 'resolution': (np.abs(dlon), np.abs(dlat)),
                 'boundingbox': boundingbox}