Excel slow due to Yield and Duration Functions
 

I have a sreadsheet with a lot of Yield and Duration calculations. The
sheet is calculating approximately twice per second (I think this is
the most it can do on the current machine). This is slowing the
machine down and excel is unresponsive. Is there any way that I can
improve the performance of these functions? Maybe by replicating them
in vba modules?

Thanks,

Paul.