On Mon, Jun 8, 2009 at 5:44 PM, <[email protected]> wrote: > > Hi, folks. Unable to find a printed reference for the definition we use to > compute the functions in the Subject line of this email, I posted a couple > queries for help in this regard in the Discussion for fv > (http://docs.scipy.org/numpy/docs/numpy.lib.financial.fv/#discussion-sec). > josef Pktd's reply (thanks!) just makes me even more doubtful that we're > using the definition that most users from the financial community would be > expecting. At this point, I have to say, I'm very concerned that our > implementation for these is "wrong" (or at least inconsistent with what's > used in financial circles); if you know of a reference - less ephemeral than > a solely electronic document - defining these functions as we've implemented > them, please share. Thanks! >
Just quickly comparing In [3]: np.lib.financial.fv(.1,10,-100,-350) Out[3]: 2501.5523211350032 With OO Calc =fv(.1,10,-100,-350) =2501.55 Both return the value of 350*1.1**10 + 100*1.1**9 + ... + 100*1.1 which is what I would expect it to do. I didn't look too closely at the docs though, so they might be a bit confusing and need some cleaning up. There was a recent discussion about numpy.financial in this thread <http://mail.scipy.org/pipermail/numpy-discussion/2009-May/042709.html>. The way that it was left is that they are there as teaching tools to mimic *some* of the functionality of spreadsheets/ financials calculators. I'm currently working on implementing some other common spreadsheet/ financial calculator on my own for possible inclusion somewhere later, as I think was the original vision <http://thread.gmane.org/gmane.comp.python.numeric.general/20027>. Skipper _______________________________________________ Numpy-discussion mailing list [email protected] http://mail.scipy.org/mailman/listinfo/numpy-discussion
