title: R: Using p.adjust to correct z-scores for multiple testing
body: <p>I have a set of normal approximated <code>z-scores</code>, which I need to correct for multiple testing, I do this by converting the <code>z-score</code> to the corresponding adjusted <code>p-value</code>, as follows:</p>
  
  <pre><code># Reproducible R-code
  z      = -24.831
  ntests = 487
  p      = 2*pnorm(-abs(z))                  # Yields p = 4.14869e-136
  p.adj  = p.adjust(p,method="fdr",n=ntests) # Yields p.adj = 2.020412e-133
  z.adj  = qnorm(1-p.adj/2) * sign(z)        # Yields z.adj = -Inf
  </code></pre>
  
  <p>So I start with <code>z = -24.831</code> and after correction for multiple testing, I have <code>z = -Inf</code>. I have a system, where I need the actual corrected <code>z-scores</code> and the value <code>-Inf</code> does not "fit" in this system.</p>
  
  <p>Can I get the actual value instead of just <code>-Inf</code> or is this a over/underflow issue?</p>