[Date Index] [Thread Index] [Author Index]
- Saturday, December 30, 1995
- Re: implicit differentiation, Dave Wagner
- Re: implicit differentiation, Dave Wagner
- Re: Mma speed trials (Win'95), Ed Oswalt
- Should I get Matlab or Mathematica or ?, Doug Wellington
- Short form for FortranForm, hedonley@grove.iup.edu
- Re: Re: FindMinimum and NIntegrate, CHAN MUN CHOONG
- Re: Mma speed trials (Win'95), Ed Oswalt
- Should I get Matlab or Mathematica or ?, Doug Wellington
- Short form for FortranForm, hedonley@grove.iup.edu
- Re: Re: FindMinimum and NIntegrate, CHAN MUN CHOONG
- Re: extract elements from a list, "Stuart C. Schaffner"
- Mathematica vs ?, Doug Wellington
- Re: extract elements from a list, Stuart C. Schaffner
- Mathematica vs ?, Doug Wellington
- Wednesday, December 27, 1995
- Can't interrupt the current evaluation, Igor Chernizr
- Re: Programming, Dave Wagner
- Re: extract elements from a list, NEWSMGR
- Re: Mathematica as a programming language., Harry A. Smith
- Re: extract elements from a list, Christian Bennefeld
- Re: Mathematica as a programming language., Ralheid
- Goto/Conditional Loops?, Andre Bindon
- Re: Programming, Dave Wagner
- Transpose of a 1x15 matrix...HOW?, Lombardo Fernando J
- Mathematica for WIN95, David Elrod
- Request for Mathematica Queueing Package, John Collins
- implicit differentiation, marshall
- Sunday, December 24, 1995
- Re: Programming, Richard J Fateman
- Re: Mathlink & Macintosh & CodeWarrior, Ian Collier
- news article for your approval, EmiNet Domain News Admin
- trouble installing mathematica, Ralf Schramm
- Mathematica for Students now available for Linux, Wolfram Research
- Re: Function parameters, using : and ?, Bruce Carpenter
- Re: How to combine two graphs with different scales?, Preston Nichols
- OLE in Mma 3.2.3 Windows --- any ideas?, Matt Smith
- Re: Programming, Dave Wagner
- Re: Programming, Richard Mercer
- Polar Contour Plots, Jean-Francois Viau
- extract elements from a list, cjkelly@bu.edu
- axis scaling with altenative values, Dieter Baurecht
- Re: Function parameters, using : and ?, Allan Hayes
- Help, Monte Carlo Simulations, yong park
- Re: Programming, Robert Villegas
- Re: Programming, Preston Nichols
- Re: LISTS and more LISTS, Dave Wagner
- Re: shell command, Robert Villegas
- Re: Programming, Robert Villegas
- Re: ParametricPlot3D, Dave Wagner
- Thanks for help with lists (all who replied), Andre Bindon
- LISTS and more LISTS, cjkelly@bu.edu
- Mathematica as a programming language., ngjune
- statistics tutorials, jenny
- Sending output directly to printer?, Andre Bindon
- Mma speed trials (Win'95), Richard Morey Porter
- Wednesday, December 20, 1995
- shell command, Susan Rempe
- Re: Function?, Allan Hayes
- Programming, Jack Goldberg
- Re: Distribute, Allan Hayes
- Re: ParametricPlot3D, Hans Steffani
- Mathlink & Macintosh & CodeWarrior, Ricardo Marimon
- Function parameters, using : and ?, Ricardo Marimon
- Re: ParametricPlot3D, Allan Hayes
- Tuesday, December 19, 1995
- noise, FERRUCCIO Renzoni
- Re: Help with lists, Bruce Carpenter
- Re: Re: Oh why is life never easy? Need help with |vector|, Bruce Carpenter
- Distribute, Arnold Seiken
- Re: Re: Bug ListPlot?, Allan Hayes
- Function?, Hans Steffani
- ParametricPlot3D, Hans Steffani
- Linux & Mathematica, Chuck Moses
- Re: Re: Bug ListPlot?, Allan Hayes
- Function?, Hans Steffani
- Re: Help with lists, Bruce Carpenter
- Distribute, "Arnold Seiken"
- ParametricPlot3D, Hans Steffani
- Linux & Mathematica, Chuck Moses
- noise, FERRUCCIO Renzoni
- Monday, December 18, 1995
- Re: Mma under Win95 (slow...)?, Alexander Otte
- Re: Bug ListPlot?, John Tanner
- Re: Oh why is life never easy? Need help with |vector|, Elias Saab
- Re: Windows NT or Linux, Vincent Kwok-Shiang Loh
- Re: Oh why is life never easy? Need help with |vector|, ULI WORTMANN
- Re: Help with lists, Allan Hayes
- Sunday, December 17, 1995
- Re: Help with lists, Allan Hayes
- Re: Mma under Win95 (slow...)?, Alexander Otte
- Re: Bug ListPlot?, John Tanner
- Re: Oh why is life never easy? Need help with |vector|, ULI WORTMANN
- Re: Oh why is life never easy? Need help with |vector|, Elias Saab
- Re: Windows NT or Linux, Vincent Kwok-Shiang Loh
- book announcement, richard j. gaylord
- Re: Mma under Win95 (slow...)?, Ian Collier
- Generating Noise in Mathematica, Wilson Flip Figueroa
- Re: Mmka speed under Win95, Ian Collier
- Re: Data manipulation in Mathematica, Ian Collier
- Re: Oh why is life never easy? Need help with |vector|, Jorma Virtamo
- ParametricPlot3D, color with function ?, Christopher R. Carlen
- Re: Oh why is life never easy? Need help with |vector|, Dave Wagner
- Re: math notebook on sgi doesn't work ???, Dave Hart
- Mmka speed under Win95, Maxim S. Popov
- Re; Problem with Packages, Andre Bindon
- Help with lists, Andre Bindon
- Re: Question on NDSolve (Mathematica), Dave Wagner
- Re: Isomorphic Graphs, Hiroshi Murakami
- Re: Bug ListPlot?, Dave Wagner
- Error Message, Edgar Camacho Cota
- How to combine two graphs with different scales?, Tobias Cottmann
- ParametricPlot3D, color with function ?, Christopher R. Carlen
- Infinity, CHAN MUN CHOONG
- Re: Oh why is life never easy? Need help with |vector|, Dave Wagner
- Re: Question on NDSolve (Mathematica), Dave Wagner
- Re: Bug ListPlot?, Dave Wagner
- Re: Oh why is life never easy? Need help with |vector|, Jorma Virtamo
- Infinity, CHAN MUN CHOONG
- ParametricPlot3D, color with function ?, Christopher R. Carlen
- Error Message, Edgar Camacho Cota
- Re: Data manipulation in Mathematica, Ian Collier
- Re: Mmka speed under Win95, Ian Collier
- Re: Mma under Win95 (slow...)?, Ian Collier
- Re: math notebook on sgi doesn't work ???, Dave Hart
- ParametricPlot3D, color with function ?, Christopher R. Carlen
- Re: Isomorphic Graphs, Hiroshi Murakami
- book announcement, richard j. gaylord
- How to combine two graphs with different scales?, Tobias Cottmann
- Re; Problem with Packages, Andre Bindon
- Help with lists, Andre Bindon
- Mmka speed under Win95, "Maxim S. Popov"
- Generating Noise in Mathematica, Wilson Flip Figueroa
- Saturday, December 16, 1995
- Re: How to get labels correctly plotted, Ian Collier
- Mma under Win95 (slow...)?, Leigh Smith
- Mathematica Training, Wolfram Research
- Data manipulation in Mathematica, Julius C Hedden
- Oh why is life never easy? Need help with |vector|, ULI WORTMANN
- Error message, Edgar Camacho Cota
- Re: Re: What's in the " .mb" files????, Richard Mercer
- Looking for ODE Software, Robert L. Poirrier
- Error message, Edgar Camacho Cota
- Looking for ODE Software, Robert L. Poirrier
- Mma under Win95 (slow...)?, Leigh Smith
- Mathematica Training, Wolfram Research
- Data manipulation in Mathematica, Julius C Hedden
- Re: How to get labels correctly plotted, Ian Collier
- Oh why is life never easy? Need help with |vector|, ULI WORTMANN
- Thursday, December 14, 1995
- RE: Re: Re: X-FrontEnd crashes upon certain keystrokes, John R. Fultz
- Re: Bug ListPlot?, Ian Collier
- Help [Q] with Timing[] problem, David
- RE: Bug ListPlot?, John R. Fultz
- Re: numerical solutions to matrices??, Pasquale Nardone
- Re: Bug ListPlot?, Lawrence Kearney
- How to get labels correctly plotted, Chris E. Forest
- Question on NDSolve (Mathematica), LIM OO KAW
- Question on NDSolve (Mathematica), LIM OO KAW
- Re: Bug ListPlot?, Lawrence Kearney
- How to get labels correctly plotted, Chris E. Forest
- Re: Bug ListPlot?, Ian Collier
- Help [Q] with Timing[] problem, David
- RE: Bug ListPlot?, "John R. Fultz"
- RE: Re: Re: X-FrontEnd crashes upon certain keystrokes, "John R. Fultz"
- Re: numerical solutions to matrices??, Pasquale Nardone
- Wednesday, December 13, 1995
- Speedcomparison of Mathematica on Various Machines, Stefan Steinhaus
- Re: Linear optimization, Paul A. Rubin
- Re: Windows NT or Linux, Ian Collier
- Re: Mathematica 2.2.3 on Windows 95, Richard Morey Porter
- Re: How to simplify transposed terms?, Paul A. Rubin
- Re: Mathematica 2.2.3 on Windows 95, Ian Collier
- numerical solutions to matrices??, Clark Snowdall
- Re: Help : Plotting vectors in 3D Graphics, Goroch, Dr. Andy
- Singular Matrix error in FindRoot ?, Axel Kowald
- Re: Mathematica 2.2.3 on Windows 95, John Carroll
- Re: Re: X-FrontEnd crashes upon certain keystrokes, George Jefferson
- Bug ListPlot?, Will Self
- Re: ContourPlot, Marcus Vinicius Mesquita de Sousa
- inverse Fourier Transforms, L.W.Sterritt
- Re: Mathematica 2.2.3 on Windows 95, John Carroll
- numerical solutions to matrices??, Clark Snowdall
- inverse Fourier Transforms, "L.W.Sterritt"
- Re: Linear optimization, Paul A. Rubin
- Re: How to simplify transposed terms?, Paul A. Rubin
- Re: ContourPlot, Marcus Vinicius Mesquita de Sousa
- Re: Re: X-FrontEnd crashes upon certain keystrokes, George Jefferson
- Bug ListPlot?, Will Self
- Re: Windows NT or Linux, Ian Collier
- Re: Mathematica 2.2.3 on Windows 95, Ian Collier
- Re: Help : Plotting vectors in 3D Graphics, "Goroch, Dr. Andy"
- Speedcomparison of Mathematica on Various Machines, Stefan Steinhaus
- Singular Matrix error in FindRoot ?, Axel Kowald
- Re: Mathematica 2.2.3 on Windows 95, Richard Morey Porter
- Tuesday, December 12, 1995
- Linear optimization, M. Lange YPE
- Re: Windows NT or Linux, Vincent Kwok-Shiang Loh
- Evaluating a Notebook an nohup?, Ricardo Marimon
- Re: Comparison of MMA on Various Machines, Gerhard Braunshausen
- Mathematica 2.2.3 on Windows 95, Elias Saab
- Re: Comparison of MMA on Various Machines, Gerhard Braunshausen
- Re: FrontEnd Message: 'Lost Connection to License Server', Gerhard Braunshausen
- Re: FindMinimum and NIntegrate, Sirpa Saarinen
- Re: Windows NT or Linux, david
- Subscript in Graphics, Andreas Fischer
- Help : Plotting vectors in 3D Graphics, Cedric Pillonel
- Re: Mathematica with Windows 95, david
- Monday, December 11, 1995
- Mathematica 2.2.3 on Windows 95, Elias Saab
- Re: Windows NT or Linux, Vincent Kwok-Shiang Loh
- Re: FrontEnd Message: 'Lost Connection to License Server', Gerhard Braunshausen
- Help : Plotting vectors in 3D Graphics, Cedric Pillonel
- Re: Windows NT or Linux, david
- Evaluating a Notebook an nohup?, Ricardo Marimon
- Linear optimization, "M. Lange YPE"
- Subscript in Graphics, Andreas Fischer
- Re: Comparison of MMA on Various Machines, Gerhard Braunshausen
- Re: Comparison of MMA on Various Machines, Gerhard Braunshausen
- Sunday, December 10, 1995
- Re: your mail, Tim Mooney
- Re: Mathematica with Windows 95, Luke
- Thanks for the help with contours and implicit plots!, Brian James Clever
- Re: Re: X-FrontEnd crashes upon certain keystrokes, Elias Saab
- Re: your mail, Ian Collier
- Re: math notebook on sgi doesn't work ???, Elias Saab
- Re: Mathematica under WinOS/2, Scot_Gould
- Re: How to plot solutions to conics and elliptics?, Elias Saab
- Re: your mail, Ian Collier
- Re: Re: X-FrontEnd crashes upon certain keystrokes, Elias Saab
- Re: How to plot solutions to conics and elliptics?, Elias Saab
- Re: math notebook on sgi doesn't work ???, Elias Saab
- Re: Mathematica under WinOS/2, Scot_Gould
- Saturday, December 09, 1995
- Thanks for the help with contours and implicit plots!, Brian James Clever
- Re: Mathematica with Windows 95, Luke
- Re: your mail, Tim Mooney
- Re: Import/Export of data to/from Mma and Excel., Des Penny
- Re: FindMinimum and picewise linear functions, Paul A. Rubin
- Re: How to simplify transposed terms?, Paul A. Rubin
- Re: Re: switch list elements, index from inside ??, Allan Hayes
- Re: Comparison of MMA on Various Machines, Ian Collier
- Re: HELP! Memory problem?, Ian Collier
- Re: Box counting dimension for fractals via Mathematica??, Pasquale Nardone
- question on caching, Vincent Kwok-Shiang Loh
- Re: Help with contour plots, please?, Ian Collier
- Re: Comparison of MMA on Various Machines, Charles Bouldin
- Re: 3-D graphics to GIF, Ian Collier
- Re: What's in the " .mb" files????, Dave Wagner
- Re: Scientific Web - Speedcomparison Mathematica 2, Vincent Kwok-Shiang Loh
- FindMinimum and NIntegrate, CHAN MUN CHOONG
- Re: Mathematica with Windows 95, Ian Collier
- math notebook on sgi doesn't work ???, Atipat Rojnuckarin
- Re: [Q] Thread ??, Bart van der Zwet
- Re: mathematica and mac-slip, George Jefferson
- Mathematica related Web sites, Monica Davis
- Re: Partial Differential Equations in Mathematica, Sirpa Saarinen
- Re: mathematica and mac-slip, Mario Garcia
- Re: Mathematica under WinOS/2, Ladislav Sedivy
- Re: Scientific Web - Speedcomparison Mathematica 2, Allan Hayes
- Re: Question about LISTS, Christian Jost
- Box counting dimension for fractals via Mathematica??, Richard EASTHER
- Re: How to plot solutions to conics and elliptics?, David Harvatin
- Re: Mathematica under WinOS/2, hasmith
- Analytica Users ?, Christian Bennefeld
- Partial Differential Equations in Mathematica, Kendall Reeves
- Comparison of Mathematica on Various Computers, Karl Unterkofler
- Files required to interface mma with C., Bryan Miller
- How to plot solutions to conics and elliptics?, Brian James Clever
- Finding the serie's pattern ?, Jean Moreau
- Isomorphic Graphs, Simon Robertson
- Mathematica with Windows 95, Ram Piyaket
- FindMinimum and NIntegrate, CHAN MUN CHOONG
- Re: Scientific Web - Speedcomparison Mathematica 2, Allan Hayes
- Re: Import/Export of data to/from Mma and Excel., Des Penny
- Re: Partial Differential Equations in Mathematica, Sirpa Saarinen
- Re: Mathematica with Windows 95, Ian Collier
- Re: [Q] Thread ??, "Bart van der Zwet"
- math notebook on sgi doesn't work ???, Atipat Rojnuckarin
- Mathematica related Web sites, Monica Davis
- Re: How to simplify transposed terms?, Paul A. Rubin
- Re: FindMinimum and picewise linear functions, Paul A. Rubin
- Re: Comparison of MMA on Various Machines, Charles Bouldin
- Mathematica with Windows 95, Ram Piyaket
- Finding the serie's pattern ?, Jean Moreau
- Re: Help with contour plots, please?, Ian Collier
- Re: Comparison of MMA on Various Machines, Ian Collier
- Re: Box counting dimension for fractals via Mathematica??, Pasquale Nardone
- Re: Question about LISTS, Christian Jost
- Partial Differential Equations in Mathematica, Kendall Reeves
- Re: How to plot solutions to conics and elliptics?, David Harvatin
- Re: What's in the " .mb" files????, Dave Wagner
- How to plot solutions to conics and elliptics?, Brian James Clever
- Comparison of Mathematica on Various Computers, Karl Unterkofler
- Re: mathematica and mac-slip, George Jefferson
- Analytica Users ?, Christian Bennefeld
- Isomorphic Graphs, Simon Robertson
- Box counting dimension for fractals via Mathematica??, Richard EASTHER
- question on caching, Vincent Kwok-Shiang Loh
- Re: Scientific Web - Speedcomparison Mathematica 2, Vincent Kwok-Shiang Loh
- Re: Re: switch list elements, index from inside ??, Allan Hayes
- Re: Comparison of MMA on Various Machines, Sinan Karasu
- Re: making real postcript graphs????, George Jefferson
- Friday, December 08, 1995
- Re: Comparison of MMA on Various Machines, Sinan Karasu
- Re: making real postcript graphs????, George Jefferson
- Scientific Web - Speedcomparison Mathematica 2, Stefan Steinhaus
- Re: Windows NT or Linux, Ian Collier
- Re: mathematica and mac-slip, Bill Rowe
- Re: Mathematica under WinOS/2, hasmith
- Re: mathematica and mac-slip, Ian Collier
- Wednesday, December 06, 1995
- Re: Mathematica under WinOS/2, hasmith
- Re: Mathematica under WinOS/2, Ladislav Sedivy
- Re: mathematica and mac-slip, Ian Collier
- Re: mathematica and mac-slip, Bill Rowe
- Re: HELP! Memory problem?, Ian Collier
- Re: Windows NT or Linux, Ian Collier
- Re: 3-D graphics to GIF, Ian Collier
- Re: mathematica and mac-slip, Mario Garcia
- Scientific Web - Speedcomparison Mathematica 2, Stefan Steinhaus
- Tuesday, December 05, 1995
- Re: switch list elements, index from inside ??, David Withoff
- Re: Windows NT and Linux, Dr Pierre E. Ravussin,
- Mathematica under WinOS/2, hasmith
- Re: Smith Normal Form Algorithm, CRStover
- FindMinimum and picewise linear functions, Sinan Karasu
- Re: X-FrontEnd crashes upon certain keystrokes, Mario Garcia
- mathematica and mac-slip, Motti
- 3-D graphics to GIF, Ed Hall
- mathematica and mac-slip, Motti
- Mathematica under WinOS/2, hasmith
- Re: Smith Normal Form Algorithm, CRStover
- FindMinimum and picewise linear functions, Sinan Karasu
- Re: X-FrontEnd crashes upon certain keystrokes, Mario Garcia
- 3-D graphics to GIF, Ed Hall
- Re: Windows NT and Linux, Dr Pierre E. Ravussin,
- Re: switch list elements, index from inside ??, David Withoff
- Monday, December 04, 1995
- Re: Extremely simple problem, and NO success!, Dave Wagner
- RE: MathLink, John R. Fultz
- Re: switch list elements, index from inside ??, Allan Hayes
- Re: [Q] how fast is each machine with Mathematica ?, Dave Wagner
- HELP! Memory problem?, Andrei Gabrielian
- Re: Extremely simple problem, and NO success!, Scott Herod
- Re: [Q] how fast is each machine with Mathematica ?, Dave Wagner
- Re: switch list elements, index from inside ??, Allan Hayes
- RE: MathLink, "John R. Fultz"
- Re: Extremely simple problem, and NO success!, Scott Herod
- HELP! Memory problem?, Andrei Gabrielian
- Sunday, December 03, 1995
- Re: DistributionsCommon, Ian Collier
- Re: Q> on COMBINING PLOTS w/ diff. axes. (LONG), Preston Nichols
- Re: Peculiar behavior of Integrate, David Withoff
- Extremely simple problem, and NO success!, Roland Larsson
- Using C code on a Mac question?, Michael A. Rutter
- Re: How to write a loop, Carola Friederike Berger
- MathLink, Dietrich Foerster
- Re: [Q] how fast is each machine with Mathematica ?, Richard EASTHER
- Re: Re: Re: What's in the " .mb" files????, Richard Mercer
- Re: help, Carola Friederike Berger
- switch list elements, index from inside ??, davep
- Re; Mathematica 2.2.1 upgrade/ChemicalElements, Andre Bindon
- Converting Mathematica output into WinWord 6 equitations, Marc Ellenrieder
- derivatives of indexed variables, George Jefferson
- Point Labels on XY plot, Jason
- Re: help, Robert Pratt
- Point Labels on XY plot, Jason
- Thank you for informations, Kentaro Kondo
- Re: help, Allan Hayes
- WTB Mathematica 2.2x Proffessional for MAC, Dan Sternberg
- PDE Systems., Dave Snead
- Mathematica on Linux, Buelent Zeyben
- overlaping cells, Edgar Camacho Cota
- Re: Peculiar behavior of Integrate, David Withoff
- Extremely simple problem, and NO success!, Roland Larsson
- Re: Re: Re: What's in the " .mb" files????, Richard Mercer
- Re: [Q] how fast is each machine with Mathematica ?, Richard EASTHER
- Re: DistributionsCommon, Ian Collier
- Re: How to write a loop, Carola Friederike Berger
- Re: help, Carola Friederike Berger
- PDE Systems., Dave Snead
- Re: help, Robert Pratt
- Re: Q> on COMBINING PLOTS w/ diff. axes. (LONG), Preston Nichols
- Converting Mathematica output into WinWord 6 equitations, Marc Ellenrieder
- Mathematica on Linux, Buelent Zeyben
- overlaping cells, Edgar Camacho Cota
- switch list elements, index from inside ??, davep
- MathLink, Dietrich Foerster
- Using C code on a Mac question?, Michael A. Rutter
- Point Labels on XY plot, Jason
- Re: help, Allan Hayes
- WTB Mathematica 2.2x Proffessional for MAC, Dan Sternberg
- derivatives of indexed variables, George Jefferson
- Point Labels on XY plot, Jason
- Thank you for informations, Kentaro Kondo
- Re; Mathematica 2.2.1 upgrade/ChemicalElements, Andre Bindon
- Saturday, December 02, 1995
- Re: Question about thread, Dave Wagner
- Re: Limiting mma caching (??), Dave Wagner
- Re: Using C code on a Mac question?, News Owner
- Re: [Q] how fast is each machine with Mathematica ?, Richard EASTHER
- Re: help, Ian Collier
- Friday, December 01, 1995
- Re: X-FrontEnd crashes upon certain keystrokes, Ian Collier
- Re: LUDecomposition output?, Daniel Lichtblau
- Re: Point Labels on XY plot,
- getting eps files from mathematica on a mac, Richard EASTHER
- Re: Point Labels on XY plot, Ian Collier
- Re: Positive[a] = True ???, Johan Gunnarsson
- (fwd) INVITATION: Preregister for ICM98 !!! IMU and ICM98-servers in action, Rainer Schulze
- Re: Scientific Web - Speedcomparison Mathematica 2, Ronald Bruck
- Re: derivatives of indexed variables, Scott Herod
- Re: Question about thread, Allan Hayes
- Re: Re: What's in the " .mb" files????, Ross Moore <ross@zeus.mpce.mq.edu.au>
- Re: Bug in symbolic inversion of matrices, David Withoff
- Re: Bug in symbolic inversion of matrices, Daniel Lichtblau
- Re: making real postcript graphs????, Ian Collier
- Re: X-FrontEnd crashes upon certain keystrokes, Scott Herod
- Re: Bug in symbolic inversion of matrices, Dr. Stefan P. Mueller
- Re: Re: [Q] {a,b,c}->{{a,b},{b,c}}, Allan Hayes
- Re: TeX output format, Ian Collier
- Re: Re; Mathematica 2.2.1 upgrade/ChemicalElements, Ian Collier
- MathLink, Dietrich Foerster
- Re: [Q] how fast is each machine with Mathematica ?, Richard EASTHER
- Peculiar behavior of Integrate, Ronald Bruck
- Re: DistributionsCommon, Luis Fernando Segala
- Math Question, Enrico C. Walker
- Re: Re: What's in the " .mb" files????, Allan Hayes