r">Calling the integrator</h2>
<p>Suppose that our model requires evaluating the lpdf of a left-truncated normal, but the truncation limit is to be estimated as a parameter. Because the truncation point is a parameter, we must include the normalization term of the truncated pdf when computing our model’s log density. Note this is just an example of how to use the 1D integrator. The more efficient way to perform the correct normalization in Stan is described in the chapter on Truncated or Censored Data of 