title: Finding errors on Gaussian fit from covariance matrix
body: <p>So, I defined a Gaussian distribution, which I later fitted to datapoints. I defined it like this:</p>
  
  <p>def Gauss(x, a, x0, sigma):
      return a * np.exp(-(x - x0)<strong>2 / (2 * sigma</strong>2))</p>
  
  <p>popt, pcov = curve_fit(Gauss, x, y, p0=[max(y), mean, sigma])</p>
  
  <p>When I ask to print my popt, I get (as expected) a matrix that gives me the maximum y-value first, then the mean, and finally the sigma of the Gaussian. Now, I want to know the errors on these values, so I would like to know the error on my Gaussian fit. I thought that I could retrieve the errors from the pcov (covariance matrix), but when asked to print pcov, I get a 3X3 matrix. So, how do I find the error on my fit from this matrix?</p>