Dear experts,

I am trying to change the VAE example to a non MNIST dataset.

So I am trying to make the VAE learn a set a guassians with different means.

I changed the model as

```
z = pyro.sample("latent", dist.Normal(mu, sigma).independent(1))
output = self.decoder(z)
pyro.sample("data", dist.Normal(output, 0.1*torch.ones_like(output)), obs=x)
```

however the loss is NAN from the first iteration.

Probably there is something basic I am missing.

thanks in advance!