def grad_logisticv(args, direction):
# XXX The direction is a Venture value, but the deriv is a Python
# (numpy) array :(
[x] = args
(_, deriv) = T_logistic(x)
answer = direction.array * deriv
# print "Gradient of logistic got", x, deriv, direction.array, answer
return [v.VentureArrayUnboxed(answer, t.Number)]
def asVentureValue(self, thing):
thing = np.asarray(thing)
if len(thing.shape) == 0:
return vv.VentureNumber(float(thing))
elif len(thing.shape) == 1:
subtype = NumberType(thing.dtype.name)
else:
subtype = self
return vv.VentureArrayUnboxed(thing, subtype)
def testGradientOfSimulateOfLookup2():
from venture.lite.sp_registry import builtInSPs
sp = builtInSPs()["lookup"]
args = [vv.VentureArrayUnboxed([0, 0], t.Number), vv.VentureNumber(1)]
grad = sp.outputPSP.gradientOfSimulate(MockArgs(args, sp.constructSPAux()),
vv.VentureNumber(0),
vv.VentureNumber(1))
assert grad[0].lookup(vv.VentureNumber(0)) == vv.VentureNumber(0)
assert grad[0].lookup(vv.VentureNumber(1)) == vv.VentureNumber(1)
assert grad[1] == 0
def array_unboxed(self, length=None, elt_type=None, **kwargs):
if length is None:
length = npr.randint(0, 10)
if elt_type is None:
elt_type = t.NumberType(
) # TODO Do I want to test on a screwy class of unboxed arrays in general?
return v.VentureArrayUnboxed([
elt_type.asPython(
elt_type.distribution(self.__class__, **kwargs).generate())
for _ in range(length)
], elt_type)
def asVentureValue(self, thing):
return vv.VentureArrayUnboxed(thing, self.subtype)
def array(xs):
return v.VentureArrayUnboxed(np.array(xs), gp.xType)
def matrix_times_vector_grad(args, direction): (mat, vec) = args dm = np.outer(direction.array, vec) dv = np.transpose(np.multiply(np.transpose(mat), direction.array))[0] # print "Matrix times vector gradient", mat, vec, direction, dm, dv return [vv.VentureMatrix(dm), vv.VentureArrayUnboxed(dv, t.Number)]
def grad_vector_times_scalar(args, direction):
dot_prod = v.vv_dot_product(v.VentureArrayUnboxed(args[0], t.NumberType()),
direction)
return [direction * args[1], v.VentureNumber(dot_prod)]