# Can't create tensors as shown in first Captum Titanic tutorial?!

**URL:** <https://discuss.pytorch.org/t/cant-create-tensors-as-shown-in-first-captum-titanic-tutorial/208024>\
**Category:** Captum\
**Created:** [August 13, 2024, 4:26pm UTC](https://discuss.pytorch.org/t/cant-create-tensors-as-shown-in-first-captum-titanic-tutorial/208024 "2024-08-13T16:26:29Z")\
**Posts on this page:** 4\
**Page:** 1

<div class="post-metadata">

**Author:** ![rbelew](https://discuss.pytorch.org/user_avatar/discuss.pytorch.org/rbelew/32/66503_2.png) [@rbelew](https://discuss.pytorch.org/u/rbelew)\
**Post date:** [August 13, 2024, 4:26pm UTC](https://discuss.pytorch.org/t/cant-create-tensors-as-shown-in-first-captum-titanic-tutorial/208024/1 "2024-08-13T16:26:29Z")

</div>

I’m stumped by the simplest part of the most basic “Titanic Basic” [captum tutorial](https://captum.ai/tutorials/Titanic_Basic_Interpret): converting the data into tensors?!

After getting the data and performing the first preprocessing steps,  
converting to numpy arrays and separating out train and test sets works fine:

```
	data = titanic_data.to_numpy()

	train_indices = np.random.choice(len(labels), int(0.7*len(labels)), replace=False)
	test_indices = list(set(range(len(labels))) - set(train_indices))
	train_features = data[train_indices]
	train_labels = labels[train_indices]
	test_features = data[test_indices]
	test_labels = labels[test_indices]

```

but converting to tensors doesn’t work:

```
	File ".../Titanic_Basic_Interpret.py", line 139, in <module>
	input_tensor = torch.as_tensor(train_features,dtype=torch.float32)
	^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
	TypeError: can't convert np.ndarray of type numpy.object_. The only supported types are: float64, float32, float16, complex64, complex128, int64, int32, int16, int8, uint8, and bool.

```

Maybe the problem is [“no more magic, convert\_objects has been  
deprecated in pandas 0.17” ](https://stackoverflow.com/a/21197863)? It seems the tutorial was added back in 2019, but other issues seem to have used it more recently?

I’ve tried some of the suggestions there (building a separate dictionary of data types and then `data = data.astype(dtype=dtypeDict)`, converting each column separately:

```
	for c in titanic_data.columns:
	    titanic_data[c] = pd.to_numeric(titanic_data[c])

```

but these don’t go thru either. What could the issue be?!

---

<div class="post-metadata">

**Author:** ![ptrblck](https://discuss.pytorch.org/user_avatar/discuss.pytorch.org/ptrblck/32/1823_2.png) [@ptrblck](https://discuss.pytorch.org/u/ptrblck)\
**Post date:** [August 13, 2024, 9:31pm UTC](https://discuss.pytorch.org/t/cant-create-tensors-as-shown-in-first-captum-titanic-tutorial/208024/2 "2024-08-13T21:31:23Z")

</div>

Your `np.array` is an `object`, which cannot be transformed to a tensor directly.  
This can be the case if your array contains different incompatible types:

```python
a = np.array([1.0, tuple((1, 1))])
print(a.dtype)
# object

```

You could try to transform the array to a numerical dtype first via `.astype()` before transforming it to a tensor.

---

<div class="post-metadata">

**Author:** ![rbelew](https://discuss.pytorch.org/user_avatar/discuss.pytorch.org/rbelew/32/66503_2.png) [@rbelew](https://discuss.pytorch.org/u/rbelew)\
**Post date:** [August 13, 2024, 11:24pm UTC](https://discuss.pytorch.org/t/cant-create-tensors-as-shown-in-first-captum-titanic-tutorial/208024/3 "2024-08-13T23:24:41Z")

</div>

hi @ptrblck thanks so much. that is indeed the problem.

I’ve tried two of the suggestions mentioned in that SO post: ([https://stackoverflow.com/a/21197863:](https://stackoverflow.com/a/21197863:)

1. building a separate dictionary of data types and then `data = data.astype(dtype=dtypeDict)`, as suggested here:  
[python - Assign pandas dataframe column dtypes - Stack Overflow](https://stackoverflow.com/a/43289220)

2. converting each column separately, as the first answer here:  
[python - Assign pandas dataframe column dtypes - Stack Overflow](https://stackoverflow.com/a/21197863)

but these don’t go thru either. How am I supposed to do this? (And  
why am I the one bumping into this issue on a captum tutorial from  
2019?!)

---

<div class="post-metadata">

**Author:** ![rbelew](https://discuss.pytorch.org/user_avatar/discuss.pytorch.org/rbelew/32/66503_2.png) [@rbelew](https://discuss.pytorch.org/u/rbelew)\
**Post date:** [August 14, 2024, 3:24pm UTC](https://discuss.pytorch.org/t/cant-create-tensors-as-shown-in-first-captum-titanic-tutorial/208024/4 "2024-08-14T15:24:27Z")

</div>

way simpler than I’d imagined: `data = data.astype(np.float32)` is all that was required!