History and Authorship of To Be Continued ...
Version 1
- 1985 Bruce Peckham, a Ph.D. graduate student under the direction of
R.P. McGehee, in the School of Mathematics,
University of Minnesota, Twin Cities, begins to develop the software.
The original intent is to investigate a specific
two-parameter family of maps of the plane which were generated by
"return maps at the time period of forcing" of periodically forced planar
oscillators. The specific computational goal is to be able to
"continue" bifurcations
such as saddle-nodes as curves in a two-parameter space.
The program is written in C, with graphics routines using the
Silicon Graphics `gl' graphics libraries.
- 1986-7 Mark Meuer, an undergraduate at the UMTC, writes original
graphics routines which allow two separate plotting windows - one for the
phase plane, and the other for the parameter plane. Routines for translating,
zooming, and selecting points on the screen from the mouse are also written.
- 1987-8 Gary Weinstien, undergraduate research assistant at UMTC, writes a module to
compute rotation numbers of orbits of maps of the plane using Bruce Peckham's
concept of "self rotation number" which he developed as part of his Ph.D.
thesis.
- 1988 Bruce Peckham graduates from UMTC and has no access to Silicon
Graphics machines for two and 1/2 years: 1988-90 at Boston University, and
1990-91 at University of Minnesota, Duluth. (NOTE: BP wasted Winter Quarter
1990-91 trying unsuccessfully to revive a Silicon Graphics IRIS 3150 which
was cast off by the Dynamical Systems Group at the University of Minnesota,
Twin Cities. The machine was later purchased from the University by Scott
Hollatz; he made it functional for a while before it caught fire in his
parents' basement. May it rest in peace.)
The state of the program as of
1988 is what is later labelled "Version 1."
Version 2
- 1991-94 Bruce Peckham, Assistant Professor at University of Minnesota,
Duluth, writes a grant proposal to acquire Personal Iris 4D/30G. Software
development recommences.
Prof. Peckham
continues to add computational capabilities to the software.
Most significant is the addition of numerical routines to compute homoclinic
and heteroclinic points in addition to the prior capabilities of computing
fixed and periodic points.
- 1993-4 Eric Neilsen, graduate research assistant at UMD in the Applied and
Computational Mathematics program, converts (almost) all the user interface
communication, which had been until this points done via printf and scanf
statements, is converted to a Graphical User Interface using the FORMS
interface builder. This new version with the GUI is called
"Version 2."
Version 3
- 1994-96 Bruce Peckham, Associate Professor at University of Minnesota,
Duluth, continues to add computational capabilities to the software.
Result is called "Version 3."
- 1994-5 Jason Puckett, graduate Research Assistant at UMD in the Applied and
Computational Mathematics program, adds the "Orbit Method" as an option to
the "Point Method" for computing periodic orbits.
Version 4
- 1996-2000 Bruce Peckham, Associate Professor at University of Minnesota,
Duluth, continues to add computational capabilities to the software.
Significant additions include a menu of families of maps to choose between
instead of having to recompile for each different family. Also, continuation
methods are split into those finding individual points (NewtonNR.c),
curves (Continue_curve.c), and surfaces
(Continue_surf.c).
Result is called "Version 4." 4.0 -> 4.1 on July 1, 1996.
Also added in version 4.1: Computation of 1D stable and unstable manifolds.
Version 5
- 1999-2000 Cosmin Deciu, Graduate Research Assistant in the Applied and
Computational Mathematics program, makes a major conversion, rewriting the
GUI in XFORMS (instead of FORMS), and OpenGL instead of GL.
This allows porting the software from its former SGI only status to
SGI, SUN, Linux, ... .
Several enhancements to the graphics capablities are also made, including
the addition of postscript generation of figures from graphics
windows directly from the data (without a screen capture).
Result is called "Version 5.0" starting 6/1/00.
- 2000 Cosmin Deciu reworks the "look" of the main form as a "tab folder." All
modules are accessible via tabs on the main form. Version 5.1.
- 2001 Bruce Peckham adds a module to compute invariant circles. Version 5.2.
- 2001-2 Bruce Peckham rewrites graphics routines to allow data sets to have
"plot attributes." New Grahpics tab is added to the main form. Version 5.3.
- 2002 Bruce Peckham corrects bugs related to float vs double problems.
Version 5.3.1.
- May 2003 Bruce Peckham and graduate research assistant Krishna Kotnana
make changes necessary to compile using C++ (gpp) instead of C (gcc).
Version 5.3.2.
This page is maintained by Bruce Peckham (bpeckham@d.umn.edu)
and was last modified on Thursday, 29-May-2003 16:20:05 CDT.