Hi,

I’m trying to run the Lesson 1 jupyter notebook on my personal computer (with NVIDIA GPU), but even after all the requirements passed, I can’t figure out what this error message means in the first exemple:

```
TypeError: No loop matching the specified signature and casting
was found for ufunc add
```

It comes from the `learn.fit(0.01, 2)`

but the end of the error message mentions numpy which seems quite complicated for me as a beginner.

Did any one ran into something similar or knows what could cause this error?

Thank you for your help.

Here is the complete error message:

```
TypeError Traceback (most recent call last)
<ipython-input-13-e6c87b20ce86> in <module>()
2 data = ImageClassifierData.from_paths(PATH, tfms=tfms_from_model(arch, sz))
3 learn = ConvLearner.pretrained(arch, data, precompute=True)
----> 4 learn.fit(0.01, 2)
~/fastai/courses/dl1/fastai/learner.py in fit(self, lrs, n_cycle, wds, **kwargs)
300 self.sched = None
301 layer_opt = self.get_layer_opt(lrs, wds)
--> 302 return self.fit_gen(self.model, self.data, layer_opt, n_cycle, **kwargs)
303
304 def warm_up(self, lr, wds=None):
~/fastai/courses/dl1/fastai/learner.py in fit_gen(self, model, data, layer_opt, n_cycle, cycle_len, cycle_mult, cycle_save_name, best_save_name, use_clr, use_clr_beta, metrics, callbacks, use_wd_sched, norm_wds, wds_sched_mult, use_swa, swa_start, swa_eval_freq, **kwargs)
247 metrics=metrics, callbacks=callbacks, reg_fn=self.reg_fn, clip=self.clip, fp16=self.fp16,
248 swa_model=self.swa_model if use_swa else None, swa_start=swa_start,
--> 249 swa_eval_freq=swa_eval_freq, **kwargs)
250
251 def get_layer_groups(self): return self.models.get_layer_groups()
~/fastai/courses/dl1/fastai/model.py in fit(model, data, n_epochs, opt, crit, metrics, callbacks, stepper, swa_model, swa_start, swa_eval_freq, visualize, **kwargs)
160
161 if not all_val:
--> 162 vals = validate(model_stepper, cur_data.val_dl, metrics, epoch, seq_first=seq_first, validate_skip = validate_skip)
163 stop=False
164 for cb in callbacks: stop = stop or cb.on_epoch_end(vals)
~/fastai/courses/dl1/fastai/model.py in validate(stepper, dl, metrics, epoch, seq_first, validate_skip)
240 loss.append(to_np(l))
241 res.append([f(datafy(preds), datafy(y)) for f in metrics])
--> 242 return [np.average(loss, 0, weights=batch_cnts)] + list(np.average(np.stack(res), 0, weights=batch_cnts))
243
244 def get_prediction(x):
~/miniconda3/envs/fastai/lib/python3.6/site-packages/numpy/lib/function_base.py in average(a, axis, weights, returned)
381 wgt = wgt.swapaxes(-1, axis)
382
--> 383 scl = wgt.sum(axis=axis, dtype=result_dtype)
384 if np.any(scl == 0.0):
385 raise ZeroDivisionError(
~/miniconda3/envs/fastai/lib/python3.6/site-packages/numpy/core/_methods.py in _sum(a, axis, dtype, out, keepdims, initial)
34 def _sum(a, axis=None, dtype=None, out=None, keepdims=False,
35 initial=_NoValue):
---> 36 return umr_sum(a, axis, dtype, out, keepdims, initial)
37
38 def _prod(a, axis=None, dtype=None, out=None, keepdims=False,
TypeError: No loop matching the specified signature and casting
was found for ufunc add
```