.map in Exercise 3 - one_hot_matrix, gives error, Course 2 Week 3

In the 2.3 - Using One Hot Encodings, Exercise 3, there are 2 predefined codes below:
new_y_test = y_test.map(one_hot_matrix)
new_y_train = y_train.map(one_hot_matrix)

but when I run, it generates large error lines below, while all my upper codes passed successfully. The problem is new_y_test will be needed downstream so I cannot passed exercise 6! The error is:


ValueError Traceback (most recent call last)
in
----> 1 new_y_test = y_test.map(one_hot_matrix)
2 new_y_train = y_train.map(one_hot_matrix)

/opt/conda/lib/python3.7/site-packages/tensorflow/python/data/ops/dataset_ops.py in map(self, map_func, num_parallel_calls, deterministic)
1693 “”"
1694 if num_parallel_calls is None:
→ 1695 return MapDataset(self, map_func, preserve_cardinality=True)
1696 else:
1697 return ParallelMapDataset(

/opt/conda/lib/python3.7/site-packages/tensorflow/python/data/ops/dataset_ops.py in init(self, input_dataset, map_func, use_inter_op_parallelism, preserve_cardinality, use_legacy_function)
4043 self._transformation_name(),
4044 dataset=input_dataset,
→ 4045 use_legacy_function=use_legacy_function)
4046 variant_tensor = gen_dataset_ops.map_dataset(
4047 input_dataset._variant_tensor, # pylint: disable=protected-access

/opt/conda/lib/python3.7/site-packages/tensorflow/python/data/ops/dataset_ops.py in init(self, func, transformation_name, dataset, input_classes, input_shapes, input_types, input_structure, add_to_graph, use_legacy_function, defun_kwargs)
3369 with tracking.resource_tracker_scope(resource_tracker):
3370 # TODO(b/141462134): Switch to using garbage collection.
→ 3371 self._function = wrapper_fn.get_concrete_function()
3372 if add_to_graph:
3373 self._function.add_to_graph(ops.get_default_graph())

/opt/conda/lib/python3.7/site-packages/tensorflow/python/eager/function.py in get_concrete_function(self, *args, **kwargs)
2937 “”"
2938 graph_function = self._get_concrete_function_garbage_collected(
→ 2939 *args, **kwargs)
2940 graph_function._garbage_collector.release() # pylint: disable=protected-access
2941 return graph_function

/opt/conda/lib/python3.7/site-packages/tensorflow/python/eager/function.py in _get_concrete_function_garbage_collected(self, *args, **kwargs)
2904 args, kwargs = None, None
2905 with self._lock:
→ 2906 graph_function, args, kwargs = self._maybe_define_function(args, kwargs)
2907 seen_names = set()
2908 captured = object_identity.ObjectIdentitySet(

/opt/conda/lib/python3.7/site-packages/tensorflow/python/eager/function.py in _maybe_define_function(self, args, kwargs)
3211
3212 self._function_cache.missed.add(call_context_key)
→ 3213 graph_function = self._create_graph_function(args, kwargs)
3214 self._function_cache.primary[cache_key] = graph_function
3215 return graph_function, args, kwargs

/opt/conda/lib/python3.7/site-packages/tensorflow/python/eager/function.py in _create_graph_function(self, args, kwargs, override_flat_arg_shapes)
3073 arg_names=arg_names,
3074 override_flat_arg_shapes=override_flat_arg_shapes,
→ 3075 capture_by_value=self._capture_by_value),
3076 self._function_attributes,
3077 function_spec=self.function_spec,

/opt/conda/lib/python3.7/site-packages/tensorflow/python/framework/func_graph.py in func_graph_from_py_func(name, python_func, args, kwargs, signature, func_graph, autograph, autograph_options, add_control_dependencies, arg_names, op_return_value, collections, capture_by_value, override_flat_arg_shapes)
984 _, original_func = tf_decorator.unwrap(python_func)
985
→ 986 func_outputs = python_func(*func_args, **func_kwargs)
987
988 # invariant: func_outputs contains only Tensors, CompositeTensors,

/opt/conda/lib/python3.7/site-packages/tensorflow/python/data/ops/dataset_ops.py in wrapper_fn(*args)
3362 attributes=defun_kwargs)
3363 def wrapper_fn(*args): # pylint: disable=missing-docstring
→ 3364 ret = _wrapper_helper(*args)
3365 ret = structure.to_tensor_list(self._output_structure, ret)
3366 return [ops.convert_to_tensor(t) for t in ret]

/opt/conda/lib/python3.7/site-packages/tensorflow/python/data/ops/dataset_ops.py in _wrapper_helper(*args)
3297 nested_args = (nested_args,)
3298
→ 3299 ret = autograph.tf_convert(func, ag_ctx)(*nested_args)
3300 # If func returns a list of tensors, nest.flatten() and
3301 # ops.convert_to_tensor() would conspire to attempt to stack

/opt/conda/lib/python3.7/site-packages/tensorflow/python/autograph/impl/api.py in wrapper(*args, **kwargs)
256 except Exception as e: # pylint:disable=broad-except
257 if hasattr(e, ‘ag_error_metadata’):
→ 258 raise e.ag_error_metadata.to_exception(e)
259 else:
260 raise

ValueError: in user code:

<ipython-input-20-54cb3adeecf2>:17 one_hot_matrix  *
    one_hot = tf.reshape(one_hot,C)
/opt/conda/lib/python3.7/site-packages/tensorflow/python/util/dispatch.py:201 wrapper  **
    return target(*args, **kwargs)
/opt/conda/lib/python3.7/site-packages/tensorflow/python/ops/array_ops.py:195 reshape
    result = gen_array_ops.reshape(tensor, shape, name)
/opt/conda/lib/python3.7/site-packages/tensorflow/python/ops/gen_array_ops.py:8234 reshape
    "Reshape", tensor=tensor, shape=shape, name=name)
/opt/conda/lib/python3.7/site-packages/tensorflow/python/framework/op_def_library.py:744 _apply_op_helper
    attrs=attr_protos, op_def=op_def)
/opt/conda/lib/python3.7/site-packages/tensorflow/python/framework/func_graph.py:593 _create_op_internal
    compute_device)
/opt/conda/lib/python3.7/site-packages/tensorflow/python/framework/ops.py:3485 _create_op_internal
    op_def=op_def)
/opt/conda/lib/python3.7/site-packages/tensorflow/python/framework/ops.py:1975 __init__
    control_input_ops, op_def)
/opt/conda/lib/python3.7/site-packages/tensorflow/python/framework/ops.py:1815 _create_c_op
    raise ValueError(str(e))

ValueError: Shape must be rank 1 but is rank 0 for '{{node Reshape}} = Reshape[T=DT_FLOAT, Tshape=DT_INT32](one_hot, Reshape/shape)' with input shapes: [6], [].

Are you running the notebook on some platform other than Coursera Labs?

No, only Coursera platform.

Please post a screen capture image that shows your code for the one_hot_matrix() function.

I’ll delete it afterward to clear the Code of Conduct.

{image removed}

It says “all tests passed”

That only means it passed one set of tests. That doesn’t prove it is perfect.

It’s failing later on when it’s used in other functions.

Notice the shape parameter should be [C,]. Your code just has ‘C’.

Note that throughout the course, when you see “All tests passed”, what that really means is “Some tests passed.”

1 Like

It worked. Thanks for your help.

No problem.

I think your original code would have worked if you used “shape=[C,]” in the second line.