1 files changed, 40 insertions, 0 deletions
diff --git a/error.py b/error.py
new file mode 100644
index 0000000..5ea37ad
--- /dev/null
+++ b/error.py
@@ -0,0 +1,40 @@
+from theano import tensor
+import theano
+import numpy
+
+def const(v):
+    if theano.config.floatX == 'float32':
+        return numpy.float32(v)
+    else:
+        return numpy.float64(v)
+
+rearth = const(6371)
+deg2rad = const(3.141592653589793 / 180)
+
+def hdist(a, b):
+    lat1 = a[:, 0] * deg2rad
+    lon1 = a[:, 1] * deg2rad
+    lat2 = b[:, 0] * deg2rad
+    lon2 = b[:, 1] * deg2rad
+
+    dlat = abs(lat1-lat2)
+    dlon = abs(lon1-lon2)
+
+    al = tensor.sin(dlat/2)**2  + tensor.cos(lat1) * tensor.cos(lat2) * (tensor.sin(dlon/2)**2)
+    d = tensor.arctan2(tensor.sqrt(al), tensor.sqrt(const(1)-al))
+
+    hd = const(2) * rearth * d
+
+    return tensor.switch(tensor.eq(hd, float('nan')), (a-b).norm(2, axis=1), hd)
+
+def erdist(a, b):
+    lat1 = a[:, 0] * deg2rad
+    lon1 = a[:, 1] * deg2rad
+    lat2 = b[:, 0] * deg2rad
+    lon2 = b[:, 1] * deg2rad
+    x = (lon2-lon1) * tensor.cos((lat1+lat2)/2)
+    y = (lat2-lat1)
+    return tensor.sqrt(tensor.sqr(x) + tensor.sqr(y)) * rearth
+
+def rmsle(a, b):
+    return tensor.sqrt( ( (tensor.log(a+1)-tensor.log(b+1)) ** 2 ).mean() )