astropy/astropy — pull request #1106 by astrofrog (2013-05-17 21:48:11+00:00)
Title: Gaussian1dModel.stddev is incorrectly used

While trying to fit some data, I noticed that the ``Gaussian1DModel`` is wrong:

```
def eval(self, x, params):
return params[0] * np.exp((-(1/(params[2]**2)) *
(x-params[1])**2))
```

it should be:

```
def eval(self, x, params):
return params[0] * np.exp((-(0.5/(params[2]**2)) *
(x-params[1])**2))
```