|Bill Allombert on Wed, 26 May 2010 00:50:06 +0200|
[Date Prev] [Date Next] [Thread Prev] [Thread Next] [Date Index] [Thread Index]
|Re: setseriesprecision in library mode|
On Tue, May 25, 2010 at 06:22:05PM -0400, Mike McLendon wrote: > Hi, > > I'm using the PARI library and would like to increase the series > precision. I see that there is a prototype of a function called > "setseriesprecision" in the paridecl.h header file under the > /*default.c*/ comment. However, the "default.c" source code file does > not implement the "setseriesprecision" function. (Though it does > implement the "getrealprecision" and "setrealprecision" functions, > both of which I can use in my code.) I'm using pari-2.3.5 (stable). Yes, you can change the global variable precdl. This is more or less documented in the file src/functions/programming/default (If you compile default(seriesprecision,30); with GP2C, you get precdl = 30;) I recorded this error in paridecl.h, thanks. > I would like to increase the series precision so that functions like > tan(x) are more accurate when using the "gtopoly" function to convert > the series to a poly and then the "gsubstr" function to evalute the > poly at specific values. Perhaps the is also another way to do this? > Any help would be appreciated. Thanks! Well, another way would be to convert your polynomial to a series with the right precision before calling gtan(x), for example: gtan(poltoser(x,varn(x),n)) where is the precision you want. Cheers, Bill.