python: slope.py: Deduce grid dimensions from file data.

* python/slope.py: Import math module.  Use file data instead of
file header.

1 files changed, 15 insertions, 9 deletions

diff --git a/python/slope.py b/python/slope.py
index 4a5fa4b..eb4850b 100755
--- a/python/slope.py
+++ b/python/slope.py
@@ -3,21 +3,27 @@
 import matplotlib.colors as colors
 import matplotlib.pyplot as plt
 import numpy as np
+import math
 import os
 
 with open('./topography.txt', "r") as data:
-    while True:
-        p = data.tell()
-        line = data.readline()
-        col1, col2, col3 = line.strip().split()
-        if col2 == 'ncols': NXCELL = int(col3) #number of cells in x direction
-        if col2 == 'nrows': NYCELL = int(col3) #number of cells in y direction
-        if not line.startswith('#'):
-            data.seek(p) # go back one line
-            break
+    # while True:
+    #     p = data.tell()
+    #     line = data.readline()
+    #     col1, col2, col3 = line.strip().split()
+    #     if col2 == 'ncols': NXCELL = int(col3) #number of cells in x direction
+    #     if col2 == 'nrows': NYCELL = int(col3) #number of cells in y direction
+    #     if not line.startswith('#'):
+    #         data.seek(p) # go back one line
+    #         break
 
     x, y, z = np.loadtxt(data, delimiter=' ', unpack=True)
 
+xmax   = (x[0]+x[-1])                     # domain extent in x-direction
+ymax   = (y[0]+y[-1])                     # domain extent in y-direction
+NXCELL = int(math.sqrt(len(x)*xmax/ymax)) # number of cells in x-direction
+NYCELL = int(len(x)/NXCELL)               # number of cells in y-direction
+
 # first reshape to 2-D array then rotate by ninety degrees and flip in
 # vertical direction to conform to FullSWOF indexing convention
 x_co = np.flipud(np.rot90(np.reshape(x, (NXCELL,NYCELL)))) # x co-ordinates