Re: [Numpy-discussion] add xirr to numpy financial functions?

2009-05-26 Thread Alan G Isaac
Would you like to put xirr in econpy until it finds a home in SciPy? (Might as well make it available.) Cheers, Alan Isaac ___ Numpy-discussion mailing list Numpy-discussion@scipy.org http://mail.scipy.org/mailman/listinfo/numpy-discussion

Re: [Numpy-discussion] add xirr to numpy financial functions?

2009-05-26 Thread josef . pktd
I rewrote irr to use the iterative solver instead of polynomial roots so that it can also handle large arrays. For 3000 values, I had to kill the current np.irr since I didn't want to wait longer than 10 minutes When writing the test, I found that npv is missing a when keyword, for the case when

Re: [Numpy-discussion] add xirr to numpy financial functions?

2009-05-26 Thread Robert Ferrell
On May 25, 2009, at 10:59 PM, Joe Harrington wrote: Let's keep this thread focussed on the original issue: just add a floating array of times to irr or a new xirr continuous interest no more Anyone can use the timeseries package to produce a floating array of times from normal dates, if

Re: [Numpy-discussion] add xirr to numpy financial functions?

2009-05-25 Thread Joe Harrington
On Sun, 24 May 2009 18:14:42 -0400 josef.p...@gmail.com wrote: On Sun, May 24, 2009 at 4:33 PM, Joe Harrington j...@physics.ucf.edu wrote: I hate to ask for another function in numpy, but there's an obvious one missing in the financial group: xirr. ?It could be done as a new function or as

Re: [Numpy-discussion] add xirr to numpy financial functions?

2009-05-25 Thread Skipper Seabold
On Mon, May 25, 2009 at 11:50 AM, Joe Harrington j...@physics.ucf.edu wrote: On Sun, 24 May 2009 18:14:42 -0400 josef.p...@gmail.com wrote: On Sun, May 24, 2009 at 4:33 PM, Joe Harrington j...@physics.ucf.edu wrote: I hate to ask for another function in numpy, but there's an obvious one

Re: [Numpy-discussion] add xirr to numpy financial functions?

2009-05-25 Thread josef . pktd
On Mon, May 25, 2009 at 11:50 AM, Joe Harrington j...@physics.ucf.edu wrote: On Sun, 24 May 2009 18:14:42 -0400 josef.p...@gmail.com wrote: On Sun, May 24, 2009 at 4:33 PM, Joe Harrington j...@physics.ucf.edu wrote: I hate to ask for another function in numpy, but there's an obvious one

Re: [Numpy-discussion] add xirr to numpy financial functions?

2009-05-25 Thread Joe Harrington
On Mon, 25 May 2009 13:51:38 -0400, josef.p...@gmail.com wrote: On Mon, May 25, 2009 at 11:50 AM, Joe Harrington j...@physics.ucf.edu wrote: On Sun, 24 May 2009 18:14:42 -0400 josef.p...@gmail.com wrote: On Sun, May 24, 2009 at 4:33 PM, Joe Harrington j...@physics.ucf.edu wrote: I hate

Re: [Numpy-discussion] add xirr to numpy financial functions?

2009-05-25 Thread Skipper Seabold
On Mon, May 25, 2009 at 3:40 PM, Joe Harrington j...@physics.ucf.edu wrote: On Mon, 25 May 2009 13:51:38 -0400, josef.p...@gmail.com wrote: On Mon, May 25, 2009 at 11:50 AM, Joe Harrington j...@physics.ucf.edu wrote: On Sun, 24 May 2009 18:14:42 -0400 josef.p...@gmail.com wrote: On Sun,

Re: [Numpy-discussion] add xirr to numpy financial functions?

2009-05-25 Thread josef . pktd
On Mon, May 25, 2009 at 4:27 PM, Skipper Seabold jsseab...@gmail.com wrote: On Mon, May 25, 2009 at 3:40 PM, Joe Harrington j...@physics.ucf.edu wrote: On Mon, 25 May 2009 13:51:38 -0400, josef.p...@gmail.com wrote: On Mon, May 25, 2009 at 11:50 AM, Joe Harrington j...@physics.ucf.edu wrote:

Re: [Numpy-discussion] add xirr to numpy financial functions?

2009-05-25 Thread Pierre GM
Sorry to jump in a conversation I haven't followed too deep in details, but I'm sure you're all aware of the scikits.timeseries package by now. This should at least help you manage the dates operations in a straightforward manner. I think that could be a nice extension to the package:

Re: [Numpy-discussion] add xirr to numpy financial functions?

2009-05-25 Thread josef . pktd
On Mon, May 25, 2009 at 6:36 PM, Pierre GM pgmdevl...@gmail.com wrote: Sorry to jump in a conversation I haven't followed too deep in details, but I'm sure you're all aware of the scikits.timeseries package by now. This should at least help you manage the dates operations in a straightforward

Re: [Numpy-discussion] add xirr to numpy financial functions?

2009-05-25 Thread josef . pktd
The advantage of Skippers implementation using actual dates instead of just an array of numbers is that it is possible to directly calculate the annual irr, since the time units are well specified. The only problem is the need for an equation solver in numpy. Just using a date tuple would

Re: [Numpy-discussion] add xirr to numpy financial functions?

2009-05-25 Thread Pierre GM
On May 25, 2009, at 7:02 PM, josef.p...@gmail.com wrote: On Mon, May 25, 2009 at 6:36 PM, Pierre GM pgmdevl...@gmail.com wrote: Sorry to jump in a conversation I haven't followed too deep in details, but I'm sure you're all aware of the scikits.timeseries package by now. This should at

Re: [Numpy-discussion] add xirr to numpy financial functions?

2009-05-25 Thread josef . pktd
On Mon, May 25, 2009 at 7:37 PM, Pierre GM pgmdevl...@gmail.com wrote: On May 25, 2009, at 7:02 PM, josef.p...@gmail.com wrote: On Mon, May 25, 2009 at 6:36 PM, Pierre GM pgmdevl...@gmail.com wrote: Sorry to jump in a conversation I haven't followed too deep in details, but I'm sure you're

Re: [Numpy-discussion] add xirr to numpy financial functions?

2009-05-25 Thread Pierre GM
On May 25, 2009, at 8:06 PM, josef.p...@gmail.com wrote: The problem is, if the functions are enhanced in the current numpy, then scikits.timeseries is not (yet) available. Mmh, I'm not following you here... The original question was how we can enhance numpy.financial, eg. np.irr So we

Re: [Numpy-discussion] add xirr to numpy financial functions?

2009-05-25 Thread josef . pktd
On Mon, May 25, 2009 at 7:27 PM, josef.p...@gmail.com wrote: The advantage of Skippers implementation using actual dates instead of just an array of numbers is that it is possible to directly calculate the annual irr, since the time units are well specified. The only problem is the need for

Re: [Numpy-discussion] add xirr to numpy financial functions?

2009-05-25 Thread josef . pktd
On Mon, May 25, 2009 at 8:30 PM, Pierre GM pgmdevl...@gmail.com wrote: On May 25, 2009, at 8:06 PM, josef.p...@gmail.com wrote: The problem is, if the functions are enhanced in the current numpy, then scikits.timeseries is not (yet) available. Mmh, I'm not following you here... The

Re: [Numpy-discussion] add xirr to numpy financial functions?

2009-05-25 Thread Matt Knox
forgive me for jumping in on this thread and playing devil's advocate here, but I am a natural pessimist so please bear with me :) ... I think as this discussion has already demonstrated, it is *extremely* difficult to build a solid general purpose API for financial functions (even seemingly

Re: [Numpy-discussion] add xirr to numpy financial functions?

2009-05-25 Thread josef . pktd
On Mon, May 25, 2009 at 9:18 PM, Matt Knox mattknox...@gmail.com wrote: forgive me for jumping in on this thread and playing devil's advocate here, but I am a natural pessimist so please bear with me :) ... It's good to hear from a real finance person. I think as this discussion has

Re: [Numpy-discussion] add xirr to numpy financial functions?

2009-05-25 Thread Matt Knox
josef.pktd at gmail.com writes: So, while python won't get any industrial strength finance package, a more modest designer package would be feasible, if there were any interest in it (which I haven't seen). ... The even more modest question is whether we would want to match open office

Re: [Numpy-discussion] add xirr to numpy financial functions?

2009-05-25 Thread Robert Ferrell
I haven't read all the messages in detail, and I'm a consumer not a producer, but I'll comment anyways. I'd love to see additional financial functionality, but I'd like to see them in a scikit, not in numpy. I think to be useful they are too complicated to go into numpy. A couple of my

Re: [Numpy-discussion] add xirr to numpy financial functions?

2009-05-25 Thread Robert Ferrell
On May 25, 2009, at 9:15 PM, Matt Knox wrote: josef.pktd at gmail.com writes: So, while python won't get any industrial strength finance package, a more modest designer package would be feasible, if there were any interest in it (which I haven't seen). ... The even more modest question

Re: [Numpy-discussion] add xirr to numpy financial functions?

2009-05-25 Thread Joe Harrington
Let's keep this thread focussed on the original issue: just add a floating array of times to irr or a new xirr continuous interest no more Anyone can use the timeseries package to produce a floating array of times from normal dates, if those are the dates they want. If they want some

Re: [Numpy-discussion] add xirr to numpy financial functions?

2009-05-25 Thread Robert Kern
On Mon, May 25, 2009 at 23:59, Joe Harrington j...@physics.ucf.edu wrote: Let's keep this thread focussed on the original issue: just add a floating array of times to irr or a new xirr continuous interest no more Anyone can use the timeseries package to produce a floating array of times

Re: [Numpy-discussion] add xirr to numpy financial functions?

2009-05-25 Thread Skipper Seabold
On Tue, May 26, 2009 at 1:12 AM, Robert Kern robert.k...@gmail.com wrote: On Mon, May 25, 2009 at 23:59, Joe Harrington j...@physics.ucf.edu wrote: Let's keep this thread focussed on the original issue: just add a floating array of times to irr or a new xirr continuous interest no more

Re: [Numpy-discussion] add xirr to numpy financial functions?

2009-05-25 Thread Robert Kern
On Tue, May 26, 2009 at 00:20, Skipper Seabold jsseab...@gmail.com wrote: My only question then would be why have numpy.financials in the first place? You can go through the old threads for the arguments. -- Robert Kern I have come to believe that the whole world is an enigma, a harmless

Re: [Numpy-discussion] add xirr to numpy financial functions?

2009-05-25 Thread Charles R Harris
On Mon, May 25, 2009 at 6:55 PM, josef.p...@gmail.com wrote: On Mon, May 25, 2009 at 7:27 PM, josef.p...@gmail.com wrote: The advantage of Skippers implementation using actual dates instead of just an array of numbers is that it is possible to directly calculate the annual irr, since the

[Numpy-discussion] add xirr to numpy financial functions?

2009-05-24 Thread Joe Harrington
I hate to ask for another function in numpy, but there's an obvious one missing in the financial group: xirr. It could be done as a new function or as an extension to the existing np.irr. The internal rate of return (np.irr) is defined as the growth rate that would give you a zero balance at the

Re: [Numpy-discussion] add xirr to numpy financial functions?

2009-05-24 Thread josef . pktd
On Sun, May 24, 2009 at 4:33 PM, Joe Harrington j...@physics.ucf.edu wrote: I hate to ask for another function in numpy, but there's an obvious one missing in the financial group: xirr.  It could be done as a new function or as an extension to the existing np.irr. The internal rate of return