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• eriehml June 23, 2009 4:51 PM PDT    Fortran library or subroutine needed for curve fitting Hello all. I am physics grad. student and I am returning to coding after 15 years so have some patience with me.  I have experimental data points, X and Y which need to be fitted to an exponential or forth order polynomial (no other order is necessary and I could use forth order polynomial only if it easier).  The purpose of the fitting is to subtract background.  These X and Y are photoemission data (Valence Band) to be precise.  So it is only necesarry to fit the curve (exponential or forth order polynomial) to the firsts and lasts data points.  After the fit is obtained it will correspond to the background.  Then I can subtract at any X, Y the background just calculated.  Online I found this NAG library but I can not download anything but pdf files.  In the NAG library there is a subroutine called E02ADF which might help me do the fiiting but I can not download it, any body knows how access NAG downloads?  Either this subroutine or any other you might know I can give it a try as long as I can download it.  As far as the minimization algorithm I am really not picky, LM or Simplex will do for me.  I am coding in fortran using G77 compiler, windows Vista, plataform Force 2 in my laptop. My code is really simple I just need to handle too many data to fit manually each one of them.  I appreciate your time, everyone's.  Thanks for your help. David White June 23, 2009 5:15 PM PDT Rate   #1 Re: Fortran library or subroutine needed for curve fitting Quoting - eriehml Hello all. I am physics grad. student and I am returning to coding after 15 years so have some patience with me.  I have experimental data points, X and Y which need to be fitted to an exponential or forth order polynomial (no other order is necessary and I could use forth order polynomial only if it easier).  The purpose of the fitting is to subtract background.  These X and Y are photoemission data (Valence Band) to be precise.  So it is only necesarry to fit the curve (exponential or forth order polynomial) to the firsts and lasts data points.  After the fit is obtained it will correspond to the background.  Then I can subtract at any X, Y the background just calculated.  Online I found this NAG library but I can not download anything but pdf files.  In the NAG library there is a subroutine called E02ADF which might help me do the fiiting but I can not download it, any body knows how access NAG downloads?  Either this subroutine or any other you might know I can give it a try as long as I can download it.  As far as the minimization algorithm I am really not picky, LM or Simplex will do for me.  I am coding in fortran using G77 compiler, windows Vista, plataform Force 2 in my laptop. My code is really simple I just need to handle too many data to fit manually each one of them.  I appreciate your time, everyone's.  Thanks for your help. The NAG libraries are probably only available via license.  You may want to try Netlib (www.netlib.org) for a range of Fortran and other sources for many statistical and other operations.  eriehml June 23, 2009 5:57 PM PDT Rate   #2 Reply To #1 Re: Fortran library or subroutine needed for curve fitting Thanks.  I already had that done and netllib.org libraries where no help, they have a very good search engine so looking for stuff you need is not so painful.  Such elementary stuff like what I need I hope is not on license but if NAG has to sell me the subroutine I need then I will be glad to pay.  Thanks for your time. Peter June 23, 2009 7:01 PM PDT Rate   #3 Reply To #2 Re: Fortran library or subroutine needed for curve fitting Quoting - eriehml Thanks.  I already had that done and netllib.org libraries where no help, they have a very good search engine so looking for stuff you need is not so painful.  Such elementary stuff like what I need I hope is not on license but if NAG has to sell me the subroutine I need then I will be glad to pay.  Thanks for your time.  NAG libraries are very expensive, if you are just looking for curve fitting.Intel Visual Fortran's (IVF) MKL libraries might be of help. But you need to buy a copy of IVF. Alternatively try excel 2007! eos pengwern June 24, 2009 1:47 AM PDT Rate   #4 Reply To #3 Re: Fortran library or subroutine needed for curve fitting Quoting - Peter  NAG libraries are very expensive, if you are just looking for curve fitting.Intel Visual Fortran's (IVF) MKL libraries might be of help. But you need to buy a copy of IVF. Alternatively try excel 2007! Another very good source of Fortran source code for a host of scientific applications is Alan Miller's page. Whereas most of what's on NETLIB is in Fortran 77, Alan Miller's resources are generally in Fortran 90 so are a bit more user-friendly. This may not help you if you're using g77, however. Jugoslav Dujic June 24, 2009 6:02 AM PDT Rate   #5 Re: Fortran library or subroutine needed for curve fitting Quoting - eriehml Hello all. I am physics grad. student and I am returning to coding after 15 years so have some patience with me.  I have experimental data points, X and Y which need to be fitted to an exponential or forth order polynomial (no other order is necessary and I could use forth order polynomial only if it easier). For polynomial fitting see: http://rosettacode.org/wiki/Polynomial_Fitting#Fortran LAPACK is part of Intel MKL, shipped with Intel Fortran Professional 11.0 onwards. Jugoslav www.xeffort.com anthonyrichards June 24, 2009 9:03 AM PDT Rate   #6 Reply To #5 Re: Fortran library or subroutine needed for curve fitting Quoting - Jugoslav Dujic For polynomial fitting see: http://rosettacode.org/wiki/Polynomial_Fitting#Fortran LAPACK is part of Intel MKL, shipped with Intel Fortran Professional 11.0 onwards. Or find a friend with access to MathCad and ask to borrow it. It is very good for curve fitting. greg_thorwald June 24, 2009 10:28 AM PDT Rate   #7 Re: Fortran library or subroutine needed for curve fitting Hello, Another source for Fortran routines is the NIST "Guide to Available Mathematical Software": http://gams.nist.gov/ I think there are a number of routines related to polynomials and curve fitting.  The web site has a search tool and directory tree to find what you're looking for.  I've used a few routines from that web site with good success. Regards, Greg eriehml June 24, 2009 2:44 PM PDT Rate   #8 Reply To #3 Re: Fortran library or subroutine needed for curve fitting Quoting - Peter NAG libraries are very expensive, if you are just looking for curve fitting.Intel Visual Fortran's (IVF) MKL libraries might be of help. But you need to buy a copy of IVF. Alternatively try excel 2007! Peter Thanks for your reply.  When I read the "try excel 2007!" I thought, Oh man, people with good sense of humor at this forums, so thanks for that laugh.  I had no idea about the Intel Visual Fortran you mentioned so I really appreciate you said it.  I am looking more into it as we speak and found only some info at http://software.intel.com/sites/products/collateral/hpc/compilers/fwin_brief.pdf but maybe you can answer some of my questions.  Is this a stand alone plataform/program so that I can code and compile?, do you know if the it also has some ploting libraries?, can this be installed in a laptop?, any idea of the price?  I'll keep looking into it but I would appreciate your comments.  I just found out the cost is $699, Oh my!, that is so totally out my budget unless I hit Powerball tonight. Thanks. eriehml June 24, 2009 2:50 PM PDT Rate   #9 Reply To #7 Re: Fortran library or subroutine needed for curve fitting Quoting - greg_thorwald Hello, Another source for Fortran routines is the NIST "Guide to Available Mathematical Software": http://gams.nist.gov/ I think there are a number of routines related to polynomials and curve fitting.  The web site has a search tool and directory tree to find what you're looking for.  I've used a few routines from that web site with good success. Regards, Greg Greg Thanks a lot.  I am looking into it. Erie anthonyrichards June 25, 2009 1:42 AM PDT Rate   #10 Reply To #9 Re: Fortran library or subroutine needed for curve fitting Quoting - eriehml Greg Thanks a lot.  I am looking into it. Erie I still think that if you want a quick solution with graphical display of results, MathCad is easily the quickest route. I frequently use MathCad 11 to test and debug my algorithms (and for quick display of intermediate results) before reprogramming them in Fortran for speed. You can buy MathCad 11 on E-bay for a pittance compared to getting a complete Fortran compiler + library of math functions. I attach a screen shot showing a sample fitting function that is available to a MathCad user.  Attachments  MathCadscreen1.jpg

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