add test for nanguardmode

theano/compile/tests/test_nanguardmode.py

+"""
+This test is for testing the NanGuardMode.
+"""
+from theano.compile.nanguardmode import NanGuardMode
+import numpy
+import theano
+import theano.tensor as T
+
+
+def test_NanGuardMode():
+    """
+    Tests if NanGuardMode is working by feeding in numpy.inf and numpy.nans
+    intentionally. A working implementation should be able to capture all
+    the abnormalties.
+    """
+    x = T.matrix()
+    w = theano.shared(numpy.random.randn(5, 7).astype(theano.config.floatX))
+    y = T.dot(x, w)
+
+    fun = theano.function(
+        [x], y,
+        mode=NanGuardMode(nan_is_error=True, inf_is_error=True)
+    )
+    a = numpy.random.randn(3, 5).astype(theano.config.floatX)
+    infa = numpy.tile(
+        (numpy.asarray(100.) ** 1000000).astype(theano.config.floatX), (3, 5))
+    nana = numpy.tile(
+        numpy.asarray(numpy.nan).astype(theano.config.floatX), (3, 5))
+    biga = numpy.tile(
+        numpy.asarray(1e20).astype(theano.config.floatX), (3, 5))
+
+    work = [False, False, False]
+
+    fun(a)  # normal values
+    try:
+        fun(infa)  # INFs
+    except AssertionError:
+        work[0] = True
+    try:
+        fun(nana)  # NANs
+    except AssertionError:
+        work[1] = True
+    try:
+        fun(biga)  # big values
+    except AssertionError:
+        work[2] = True
+
+    if not (work[0] and work[1] and work[2]):
+        raise AssertionError("NanGuardMode not working.")