comp.lang.idl-pvwave archive - RDF feed
type: channel
description: Messages from Usenet group comp.lang.idl-pvwave, compiled by Paulo Penteado
items: Confluent Hypergeometric Function of the First Kind
items: Re: Confluent Hypergeometric Function of the First Kind

Confluent Hypergeometric Function of the First Kind
type: item
description: Hello everyone, I am looking for the Confluent Hypergeometric Function of the First Kind in the IDL Math Library but it does not seem to be implemented! I would like to use a function similar to the Hypergeometric1F1[a, b, z] of Mathematica [http://reference.wolfram.com/mathematica/ref/ Hypergeometric1F1.html]. I have not found what I was looking for, and so decided to try to code it my self... [sigh...]. Beeing a fresh beginner in IDL this is a hard task! Would anybody know how to code an infinite series expansion like the Hypergeometric1F1? Thank you in advance for your time! Noah
creator: noahh.schwartz
date: 2008-02-20T15:44:49-00:00

Re: Confluent Hypergeometric Function of the First Kind
type: item
description: On Feb 22, 10:36 am, noahh.schwa...@gmail.com wrote: > On 21 fév, 17:26, Dan Larson <dlar...@aecom.yu.edu> wrote: > > > >> On Feb 21, 9:30 am, Spon <christoph.b...@gmail.com> wrote: > >>> On Feb 20, 3:44 pm, noahh.schwa...@gmail.com wrote: > >>>> Hello everyone, > >>>> I am looking for the ConfluentHypergeometricFunctionof the First >>>> Kind in theIDLMath Library but it does not seem to be implemented! > >>>> I would like to use afunctionsimilar to the Hypergeometric1F1[a, b, >>>> z] of Mathematica [http://reference.wolfram.com/mathematica/ref/ >>>> Hypergeometric1F1.html]. > >>>> I have not found what I was looking for, and so decided to try to code >>>> it my self... [sigh...]. Beeing a fresh beginner inIDLthis is a hard >>>> task! > >>>> Would anybody know how to code an infinite series expansion like the >>>> Hypergeometric1F1? > >>>> Thank you in advance for your time! >>>> Noah > >>> Noah, > >>> here's my attempt. It accepts only scalar inputs for A and B, while Z >>> can be a vector. I've tested it for the examples on the mathematica >>> site and it seems to give correct results, and works correctly for >>> complex input too as far as I can tell. 'Precision' is an input >>> variable to specify how close two successive iterations have to be >>> before thefunctionassumes they are the same and aborts the while >>> loop. Default is 7 (i.e. stop when results differ by 10^-7 or less). >>> If you're finding this programme is running very slow, try decreasing >>> the precision (I was surprised how fast it runs despite the while >>> loop, actually!) > >>> Ideally the input parameters should all be double precision before you >>> make the call to the funcion, but thefunctionconverts them if >>> they're not. > >>> If you want all your inputs to be vectors (not just Z), I'm sure it >>> can be done, but it'd be a bit more complicated. :-) > >>> Take care, >>> Chris > >>> FUNCTIONHYPERGEOMETRICONEFONE, A, B, Z, $ >>> PRECISION = Precision, $ >>> K = K ; K is an output par…
creator: Spon
date: 2008-02-22T12:46:29-00:00

Re: Confluent Hypergeometric Function of the First Kind
type: item
description: On Feb 22, 12:46 pm, Spon <christoph.b...@gmail.com> wrote: > On Feb 22, 10:36 am, noahh.schwa...@gmail.com wrote: > > > >> On 21 fév, 17:26, Dan Larson <dlar...@aecom.yu.edu> wrote: > >>> On Feb 21, 9:30 am, Spon <christoph.b...@gmail.com> wrote: > >>>> On Feb 20, 3:44 pm, noahh.schwa...@gmail.com wrote: > >>>> > Hello everyone, > >>>> > I am looking for the ConfluentHypergeometricFunctionof the First >>>> > Kind in theIDLMath Library but it does not seem to be implemented! > >>>> > I would like to use afunctionsimilar to the Hypergeometric1F1[a, b, >>>> > z] of Mathematica [http://reference.wolfram.com/mathematica/ref/ >>>> > Hypergeometric1F1.html]. > >>>> > I have not found what I was looking for, and so decided to try to code >>>> > it my self... [sigh...]. Beeing a fresh beginner inIDLthis is a hard >>>> > task! > >>>> > Would anybody know how to code an infinite series expansion like the >>>> > Hypergeometric1F1? > >>>> > Thank you in advance for your time! >>>> > Noah > >>>> Noah, > >>>> here's my attempt. It accepts only scalar inputs for A and B, while Z >>>> can be a vector. I've tested it for the examples on the mathematica >>>> site and it seems to give correct results, and works correctly for >>>> complex input too as far as I can tell. 'Precision' is an input >>>> variable to specify how close two successive iterations have to be >>>> before thefunctionassumes they are the same and aborts the while >>>> loop. Default is 7 (i.e. stop when results differ by 10^-7 or less). >>>> If you're finding this programme is running very slow, try decreasing >>>> the precision (I was surprised how fast it runs despite the while >>>> loop, actually!) > >>>> Ideally the input parameters should all be double precision before you >>>> make the call to the funcion, but thefunctionconverts them if >>>> they're not. > >>>> If you want all your inputs to be vectors (not just Z), I'm sure it >>>> can be done, but it'd be a bit more complicated. :-) > >>>> Take care, >>>> Ch…
creator: Spon
date: 2008-02-22T13:16:22-00:00

Re: Confluent Hypergeometric Function of the First Kind
type: item
description: On Feb 22, 8:16 am, Spon <christoph.b...@gmail.com> wrote: > On Feb 22, 12:46 pm, Spon <christoph.b...@gmail.com> wrote: > > > > > >> On Feb 22, 10:36 am, noahh.schwa...@gmail.com wrote: > >>> On 21 fév, 17:26, Dan Larson <dlar...@aecom.yu.edu> wrote: > >>>> On Feb 21, 9:30 am, Spon <christoph.b...@gmail.com> wrote: > >>>> > On Feb 20, 3:44 pm, noahh.schwa...@gmail.com wrote: > >>>> > > Hello everyone, > >>>> > > I am looking for the ConfluentHypergeometricFunctionof the First >>>> > > Kind in theIDLMath Library but it does not seem to be implemented! > >>>> > > I would like to use afunctionsimilar to the Hypergeometric1F1[a, b, >>>> > > z] of Mathematica [http://reference.wolfram.com/mathematica/ref/ >>>> > > Hypergeometric1F1.html]. > >>>> > > I have not found what I was looking for, and so decided to try to code >>>> > > it my self... [sigh...]. Beeing a fresh beginner inIDLthis is a hard >>>> > > task! > >>>> > > Would anybody know how to code an infinite series expansion like the >>>> > > Hypergeometric1F1? > >>>> > > Thank you in advance for your time! >>>> > > Noah > >>>> > Noah, > >>>> > here's my attempt. It accepts only scalar inputs for A and B, while Z >>>> > can be a vector. I've tested it for the examples on the mathematica >>>> > site and it seems to give correct results, and works correctly for >>>> > complex input too as far as I can tell. 'Precision' is an input >>>> > variable to specify how close two successive iterations have to be >>>> > before thefunctionassumes they are the same and aborts the while >>>> > loop. Default is 7 (i.e. stop when results differ by 10^-7 or less). >>>> > If you're finding this programme is running very slow, try decreasing >>>> > the precision (I was surprised how fast it runs despite the while >>>> > loop, actually!) > >>>> > Ideally the input parameters should all be double precision before you >>>> > make the call to the funcion, but thefunctionconverts them if >>>> > they're not. > >>>> > If you want all your in…
creator: Dan Larson
date: 2008-02-22T15:30:08-00:00

Re: Confluent Hypergeometric Function of the First Kind
type: item
description: noahh.schwartz@gmail.com wrote: > Hello everyone, > > I am looking for the Confluent Hypergeometric Function of the First > Kind in the IDL Math Library but it does not seem to be implemented! > > I would like to use a function similar to the Hypergeometric1F1[a, b, > z] of Mathematica [http://reference.wolfram.com/mathematica/ref/ > Hypergeometric1F1.html]. > > I have not found what I was looking for, and so decided to try to code > it my self... [sigh...]. Beeing a fresh beginner in IDL this is a hard > task! > > Would anybody know how to code an infinite series expansion like the > Hypergeometric1F1? > > Thank you in advance for your time! > Noah Dear Noah, I am a bit late but just came back to the office. I am using a Fortran-77 program which comes from the book: "Computation of Special Functions" of Zhang & Jin: http://jin.ece.uiuc.edu/routines/routines.html I very simple changed the program mchgm.for so that it works with arrays. I compile it locally and then call it with spawn in mc_kummer.pro The IDL routine looks a bit cluttered because I use it on different machines. BTW, mc_kummer uses mc_tmp() that produces a unique temporay file - replace by whatever you want. It also uses mc_setup(/mcbin) that tells it where it finds the executable - replace with your a.out. Cheers Matthias ;+ ; NAME: ; MC_KUMMER ; ; PURPOSE: ; Computes the Kummer or confluent hypergeometric function ; ; CATEGORY: ; Math. ; ; CALLING SEQUENCE: ; res = mc_kummer(a,b,x) ; ; INPUTS: ; a: parameter array ; b: parameter array ; x: variable array ; ; OUTPUTS: ; res: confluent hypergeometric series ; ; EXAMPLE: ; IDL> den = mc_kummer(-0.5d*ka , 0.5d , -0.5d*peclet_l) ; ; PROCEDURE: ; mc_kummer calls the external fortran program ; confluent_hypergeometric_series_M to compute the Kummer function ; ; REFERENCE: ; Weisstein E.W. (2004b) Hypergeometric function. ; In: MathWorld - A Wolfram Web Resource, ; Website: http://mathworld.wolfram.com/HypergeometricFunction.html ; ; MODIFICATION HISTORY: ;…
creator: Matthias Cuntz
date: 2008-03-05T22:01:23-00:00