Simplify Unique Op

pytensor/tensor/extra_ops.py

@@ -41,7 +41,7 @@ from pytensor.tensor.math import (
 )
 from pytensor.tensor.math import max as pt_max
 from pytensor.tensor.math import sum as pt_sum
-from pytensor.tensor.shape import specify_broadcastable
+from pytensor.tensor.shape import Shape_i, specify_broadcastable
 from pytensor.tensor.subtensor import advanced_inc_subtensor1, set_subtensor
 from pytensor.tensor.type import TensorType, dvector, int_dtypes, integer_dtypes, vector
 from pytensor.tensor.variable import TensorVariable
@@ -1194,23 +1194,22 @@ class Unique(Op):
         self.return_index = return_index
         self.return_inverse = return_inverse
         self.return_counts = return_counts
+        if axis is not None and axis < 0:
+            raise ValueError("Axis cannot be negative.")
         self.axis = axis
 
     def make_node(self, x):
         x = ptb.as_tensor_variable(x)
-        self_axis = self.axis
-        if self_axis is None:
+        axis = self.axis
+        if axis is None:
             out_shape = (None,)
         else:
-            if self_axis < 0:
-                self_axis += x.type.ndim
-            if self_axis < 0 or self_axis >= x.type.ndim:
+            if axis >= x.type.ndim:
                 raise ValueError(
-                    f"Unique axis {self.axis} is outside of input ndim = {x.type.ndim}"
+                    f"Axis {axis} out of range for input {x} with ndim={x.type.ndim}."
                 )
             out_shape = tuple(
-                s if s == 1 and axis != self_axis else None
-                for axis, s in enumerate(x.type.shape)
+                None if dim == axis else s for dim, s in enumerate(x.type.shape)
             )
 
         outputs = [TensorType(dtype=x.dtype, shape=out_shape)()]
@@ -1224,60 +1223,37 @@ class Unique(Op):
         return Apply(self, [x], outputs)
 
     def perform(self, node, inputs, output_storage):
-        x = inputs[0]
-        z = output_storage
-        param = {}
-        if self.return_index:
-            param["return_index"] = True
-        if self.return_inverse:
-            param["return_inverse"] = True
-        if self.return_counts:
-            param["return_counts"] = True
-        if self.axis is not None:
-            param["axis"] = self.axis
-        outs = np.unique(x, **param)
-        if (
-            (not self.return_inverse)
-            and (not self.return_index)
-            and (not self.return_counts)
-        ):
-            z[0][0] = outs
-        else:
+        [x] = inputs
+        outs = np.unique(
+            x,
+            return_index=self.return_index,
+            return_inverse=self.return_inverse,
+            return_counts=self.return_counts,
+            axis=self.axis,
+        )
+        if isinstance(outs, tuple):
             for i in range(len(outs)):
-                z[i][0] = outs[i]
+                output_storage[i][0] = outs[i]
+        else:
+            output_storage[0][0] = outs
 
     def infer_shape(self, fgraph, node, i0_shapes):
-        ret = fgraph.shape_feature.default_infer_shape(fgraph, node, i0_shapes)
-        if self.axis is not None:
-            self_axis = self.axis
-            ndim = len(i0_shapes[0])
-            if self_axis < 0:
-                self_axis += ndim
-            if self_axis < 0 or self_axis >= ndim:
-                raise RuntimeError(
-                    f"Unique axis `{self.axis}` is outside of input ndim = {ndim}."
-                )
-            ret[0] = tuple(
-                fgraph.shape_feature.shape_ir(i, node.outputs[0]) for i in range(ndim)
-            )
+        [x_shape] = i0_shapes
+        shape0_op = Shape_i(0)
+        out_shapes = [(shape0_op(out),) for out in node.outputs]
+
+        axis = self.axis
+        if axis is not None:
+            shape = list(x_shape)
+            shape[axis] = Shape_i(axis)(node.outputs[0])
+            out_shapes[0] = tuple(shape)
+
         if self.return_inverse:
-            if self.axis is None:
-                shape = (prod(i0_shapes[0]),)
-            else:
-                shape = (i0_shapes[0][self_axis],)
-            if self.return_index:
-                ret[2] = shape
-                return ret
-            ret[1] = shape
-            return ret
-        return ret
-
-    def __setstate__(self, state):
-        self.__dict__.update(state)
-        # For backwards compatibility with pickled instances of Unique that
-        # did not have the axis parameter specified
-        if "axis" not in state:
-            self.axis = None
+            shape = prod(x_shape) if self.axis is None else x_shape[axis]
+            return_index_out_idx = 2 if self.return_index else 1
+            out_shapes[return_index_out_idx] = (shape,)
+
+        return out_shapes
 
 
 def unique(
@@ -1293,6 +1269,9 @@ def unique(
         * the number of times each unique value comes up in the input array
 
     """
+    ar = as_tensor_variable(ar)
+    if axis is not None:
+        axis = normalize_axis_index(axis, ar.ndim)
     return Unique(return_index, return_inverse, return_counts, axis)(ar)