Fix(ModflowDis): zero based get_node() and get_lrc()… (#847)

* Fix(ModflowDis): zero based get_node() and get_lrc() for input parameters and output

* added test_get_lrc_get_node()

autotest/t007_test.py

@@ -1367,6 +1367,19 @@ def test_get_vertices():
     assert np.array_equal(a1, a2)
 
 
+def test_get_lrc_get_node():
+    node = 50
+    ml = flopy.modflow.Modflow()
+    dis = flopy.modflow.ModflowDis(ml, nlay=1, nrow=1, ncol=201, delr=10,
+                                   delc=1, top=50, botm=0)
+    lrc = dis.get_lrc([node, ])
+    if lrc[0] != (0, 0, 50):
+        raise AssertionError("get_lrc() is not returning zero based (k, i, j)")
+    nodes = dis.get_node(lrc)
+    if nodes[0] != node:
+        raise AssertionError('get_node() is not returning zero based node')
+
+
 def test_vertex_model_dot_plot():
     import matplotlib.pyplot as plt
     # load up the vertex example problem

flopy/modflow/mfdis.py

@@ -479,7 +479,8 @@ def get_rc_from_node_coordinates(self, x, y, local=True):
 
     def get_lrc(self, nodes):
         """
-        Get layer, row, column from a list of MODFLOW node numbers.
+        Get layer, row, column from a list of zero based
+        MODFLOW node numbers.
 
         Returns
         -------
@@ -491,20 +492,21 @@ def get_lrc(self, nodes):
         nrc = self.nrow * self.ncol
         v = []
         for node in nodes:
-            k = int(node / nrc)
+            k = int((node + 1) / nrc)
             if (k * nrc) < node:
                 k += 1
             ij = int(node - (k - 1) * nrc)
             i = int(ij / self.ncol)
             if (i * self.ncol) < ij:
                 i += 1
             j = ij - (i - 1) * self.ncol
-            v.append((k, i, j))
+            v.append((k - 1, i - 1, j))
         return v
 
     def get_node(self, lrc_list):
         """
-        Get node number from a list of MODFLOW layer, row, column tuples.
+        Get node number from a list of zero based MODFLOW
+        layer, row, column tuples.
 
         Returns
         -------