Tensor mismatch in lesson 2

[SteveFaultless]

Hi,

I get a tensor mismatch in lesson 2 when I try to run lrf=learn.lr_find()

Lesson two variable mismatch runtime error

Apparently, the data.val_dl tensor is a LongTensor where learn.lr_find() expects a FloatTensor.

I was able to fix this by going to

courses/dl1/fastai/dataset.py

And adding:

    y = y.astype(float)

At line 433.

I'm not sure that this is the best solution, and I don't know if it will negatively affect anything else because I'm new to the fastai library. I could just as easily have added

    label_arr = label_arr.astype(float)

at line 153, I think.

I am running fastai using a docker image hosted in ubuntu 16.04. I can provide any other details you may need.

[SteveFaultless]

Looking at the commit history, it seems that the error is caused by this commit: 98fad0e

 def n_hot(ids, c):
-    res = np.zeros((c,), dtype=np.float32)
+    res = np.zeros((c,), dtype=np.int8)
     res[ids] = 1
     return res

The change to np.int8 appears to have caused the problem. I changed it back to float (while removing my workaround above) and it worked fine.

[jph00]

Yup fixed now.