ggplot does not show in knitr

Hello,

I'm having some issues getting a ggplot figure to show up in the knitr
output, when placed in a loop.

Specifically, I have a loop inside a knitr chunk :

```{r fitting, warning=FALSE, fig.width=10, fig.height=10, fig.keep='high'}
for (t in 1:T)
{
     # do a regression of tgt.vals ~ predictors and compute coeffs and
fitted values (fit.vals / fit.adj.vals)

   plot( x=tgt.vals, y=fit.vals );
   plot( x=tgt.vals, y = fit.adj.vals );

   qplot( x = pred.names, y = coeffs);

}

```

The html output file shows the output of first 2 plot commands but not that
of the qplot command. Even if i remove the 2 plots and keep only the qplot
in the loop, it does not display in the html output.
The qplot just by itself, not in a loop, displays fine. Also, there are no
issues when I run in regular R.

Any suggestions of what is going on ?

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