lm_rnn.py concat returns "IndexError: list index out of range"

[gsgbills]

IndexError Traceback (most recent call last)
in ()
1 m3.freeze_to(-1)
----> 2 m3.fit(lrs/2, 1, metrics=[accuracy])
3 m3.unfreeze()
4 m3.fit(lrs, 1, metrics=[accuracy], cycle_len=1)

~/fastai/courses/dl1/fastai/learner.py in fit(self, lrs, n_cycle, wds, **kwargs)
207 self.sched = None
208 layer_opt = self.get_layer_opt(lrs, wds)
--> 209 self.fit_gen(self.model, self.data, layer_opt, n_cycle, **kwargs)
210
211 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, use_clr, metrics, callbacks, use_wd_sched, norm_wds, wds_sched_mult, **kwargs)
154 n_epoch = sum_geom(cycle_len if cycle_len else 1, cycle_mult, n_cycle)
155 fit(model, data, n_epoch, layer_opt.opt, self.crit,
--> 156 metrics=metrics, callbacks=callbacks, reg_fn=self.reg_fn, clip=self.clip, **kwargs)
157
158 def get_layer_groups(self): return self.models.get_layer_groups()

~/fastai/courses/dl1/fastai/model.py in fit(model, data, epochs, opt, crit, metrics, callbacks, kwargs)
88 batch_num += 1
89 for cb in callbacks: cb.on_batch_begin()
---> 90 loss = stepper.step(V(x),V(y))
91 avg_loss = avg_loss * avg_mom + loss * (1-avg_mom)
92 debias_loss = avg_loss / (1 - avg_mombatch_num)

~/fastai/courses/dl1/fastai/model.py in step(self, xs, y)
38 def step(self, xs, y):
39 xtra = []
---> 40 output = self.m(*xs)
41 if isinstance(output,(tuple,list)): output,*xtra = output
42 self.opt.zero_grad()

~/anaconda3/lib/python3.6/site-packages/torch/nn/modules/module.py in call(self, *input, **kwargs)
323 for hook in self._forward_pre_hooks.values():
324 hook(self, input)
--> 325 result = self.forward(*input, **kwargs)
326 for hook in self._forward_hooks.values():
327 hook_result = hook(self, input, result)

~/anaconda3/lib/python3.6/site-packages/torch/nn/modules/container.py in forward(self, input)
65 def forward(self, input):
66 for module in self._modules.values():
---> 67 input = module(input)
68 return input
69

~/anaconda3/lib/python3.6/site-packages/torch/nn/modules/module.py in call(self, *input, **kwargs)
323 for hook in self._forward_pre_hooks.values():
324 hook(self, input)
--> 325 result = self.forward(*input, **kwargs)
326 for hook in self._forward_hooks.values():
327 hook_result = hook(self, input, result)

~/fastai/courses/dl1/fastai/lm_rnn.py in forward(self, input)
129 raw_outputs.append(r)
130 outputs.append(o)
--> 131 return self.concat(raw_outputs), self.concat(outputs)
132
133

~/fastai/courses/dl1/fastai/lm_rnn.py in concat(self, arrs)
117
118 def concat(self, arrs):
--> 119 return [torch.cat([l[si] for l in arrs]) for si in range(len(arrs[0]))]
120
121 def forward(self, input):

IndexError: list index out of range

[jph00]

There isn't enough info here to replicate or fix the error. Best would be to ask on the forum including information about what you were doing when you got the error, and the details of your environment.