title: glm starting values not accepted log-link
body: <p>I want to run a Gaussian GLM with a log link and an offset.
  The following problems arise:</p>
  
  <pre><code>y &lt;- c(1,1,0,0)
  t &lt;- c(5,3,2,4)
  </code></pre>
  
  <p>No problem:</p>
  
  <pre><code>exp(coef(glm(y~1 +  offset(log(t)), family=poisson)))
  </code></pre>
  
  <p>with <code>family=gaussian</code>, starting values need to be specified, it works here:</p>
  
  <pre><code>exp(coef(glm(y~1, family=gaussian(link=log), start=0)))
  </code></pre>
  
  <p>but does not work here:</p>
  
  <pre><code>exp(coef(glm(y~1 +  offset(log(t)), family=gaussian(link=log), start=0)))
  </code></pre>
  
  <blockquote>
    <p>Error in eval(expr, envir, enclos) : cannot find valid starting values: please specify some"</p>
  </blockquote>
  
  <p>Does anyone see what's wrong (hopefully just in my coding) ?</p>