Group Explorer project history
Although it may be silly to download an old version of Group Explorer, I'm archiving them
here anyway. This is useful for viewing the history of work done on
the project, when new features were added, and when certain bugs were fixed.
2004-04-23 Bug fix:
 | The Multiplication Table sometimes retained chunking preferences that it
should have forgotten. This has been fixed. |
2004-04-22 Bug fixes:
| Some typographical errors on the Edit Multiplication Table page have
been fixed. Most notably, the directions are now pertinent to that
dialog box. (Formerly the Edit Cayley Diagram instructions were
showing up.) |
| The gray circle for highlighting the current node in a Cayley diagram
now scales in size with the nodes of the diagram, if you resize them using
the Edit Cayley Diagram dialog box. |
| Errors in the generation of the Multiplication Table would occur if
multiple groups were opened in succession, and then editing done on a
multiplication table. The problem with the Edit Multiplication Table
dialog box has been corrected. |
| The Edit Multiplication Table dialog box did not apply any changes in
priority made on the Priority & Chunking page. That, too, has been
fixed. |
2004-04-26 Bug fix:
| When checking to see if diagram axes dimension matched potent generators
dimension, Cayley Diagrams were not taking into account the priority the user
assigned those generators. They do take this into account now. |
2004-04-12 Bug fix:
| An erroneous error was being reported upon attempting to save 3D views
to .BMP files. It now is no longer reported, and saves
occur as they ought to. |
2004-03-26 Bug fixes:
| There were several bugs surrounding the saving of settings about the
sizes of the subwindows of the main application. That is, if you had
a window maximized or minimized inside Group Explorer, and then closed the
program, that window might start up very large or quite out of place the
next time you ran the program. This has been repaired. |
| Along with this, you can no longer maximize or minimize anything
except Cayley Diagrams and Objects of Symmetry. If you need to
banish any of the more permanent Group Explorer subwindows, they will hide
themselves thoroughly when you click the close button, and you can restore
them from the Window menu. |
2004-03-26 New feature:
| All the nice features added last time regarding editing Cayley
diagrams now also work for Multiplication Tables. Try clicking the
"Edit Table" button on the bottom of the multiplication view, and see all
the options available! |
2004-03-12 Bug fix:
| Due to miscapturing of mouse movements, if the user used the mouse
when opening groups, the initially displayed Cayley diagrams came out
rotated into strange positions, as if the user had just swung the mouse
about. Very odd. Fixed now. |
2004-03-22 New features:
| The Highlighter and Diagram Options dialog boxes have been eliminated,
in favor of the new "Edit Diagram" dialog box for customizing Cayley
diagram views. Improvements inherent in this change include the
following.
 | You can still spin the diagram around while you have open the Edit
Diagram window. |
| Options are now grouped sensibly in tabbed pages, and the somewhat
natural flow of decision making follows the order of the pages. |
| Instructions are present on the top of each tabbed page. |
| Any property of a group can be highlighted by shape or color, and
one can highlight one property by shape and another by color. |
| Buttons have been added to revert to the default generators for a
diagram, or to revert to the last set of generators chosen for a
diagram. |
| A slider for changing the default node size is available. |
| A button to restore the set of arrows to its default configuration
has been added. |
| A slider for changing the default arrow thickness is available. |
| One can now not only chunk the diagram by a subgroup's cosets, but
if the subgroup is normal, the agreement among arrows which connect
cosets can be emphasized by aligning the arrowheads. |
| Explanations regarding why chunking of cosets and the arrows between
them can or cannot be done appear as the user changes options. |
| One can now ask Group Explorer to ensure nodes and arcs always have
different colors, so that no possible confusion of meaning occurs. |
|
2004-01-22 New features:
| The Highlighting dialog box now allows you to set H to be the group's
center, commutator subgroup, and several other special kinds of subgroups.
This provides an easy way for you to see the generators of those
subgroups, and to then use the Change Generation dialog box to organize by
such subgroups. |
| Group Explorer can now view multiplication tables of groups. It
opens the multiplication tables for groups automatically when you open a
group, and you can hide it if you choose. You can also rearrange the
columns and rows to your liking. Try putting a normal subgroup all
the way to the upper-left, and its cosets one at a time next to it.
What do you see? |
| The Permutation view and the textual history connected to it have now
been split into two different views. These views, as well as the
Navigator, can now be hidden/shown just like the new Multiplication Table
view. |
| When you open a group, the first Cayley diagram for the group pops up
automatically, since this is what a user wants to happen nearly all of the
time when opening a group. (This only happens if a Cayley diagram
for the group exists, which is always the case for groups with fewer than
5 generators.) |
2004-01-03 Bug fixes:
| Previous release (1.3.0) claimed to have colorization of highlighting
based from yellow, but this was not always true. It is now
corrected. |
| Duplicate shortcut keys in Highlighter view corrected. |
| Erroneous dates in "Help | About" box corrected. |
2004-01-01 New features:
| Arcs now form perfect circles at appropriate times. |
| When a diagram is organized by a subgroup, the user can now ask to
have "chunks" drawn around the subgroup's cosets, to help visualize
normality and the quotient operation. This uses translucent
enclosures around sets of nodes; all use of translucence in 3D diagrams
was touched up for this release. |
| Fog level is now customizable (present, absent, or half). |
| Nodes are now shiny and shaded to give a more aesthetically pleasing
effect, and to demonstrate depth better. This feature can be toggled
on/off. |
| Labels can now be placed in front or in back of everything, and their
translucence can be toggled independently of placement. |
| Colorization of highlighting is now based from yellow, so that a
highlighted subgroup is always yellow, and its cosets vary in color.
This makes it easy to spot the subgroup among the various colors. |
| All images on web site updated to reflect the software's new graphics
capabilities. |
2003-12-30 Bug fixes:
| The highlighter behaved erroneously if highlighting was removed, then
immediately restored. It now functions correctly. |
| Various dialog boxes now have sensible tab orders for their
components, and each component has a shortcut key. The Change
Generators dialog box now centers itself on the Diagram Options dialog box
when opened. |
| A runtime error that sometimes cropped up when attempting to change
the generation of custom Cayley diagrams has been repaired. |
| Diagram reorganizations that bring nodes close together or far apart
now impact node size, so that nodes shrink to avoid overlapping, and
re-inflate to their original size when possible. |
2003-11-26 New features:
| All the three dimensional graphics are now created using
OpenGL. As a consequence, they
are more accurate and much more attractive. If you have a
sophisticated video card and the appropriate drivers installed, they will
also be able to achieve a higher frame rate. Other minor
consequences of this change include:
| The options for label positioning have changed, now that we have a
truly three-dimensional situation. |
| Printing Cayley diagrams and objects of symmetry now results in
larger printouts, which is usually more desirable. |
|
2003-11-15 Bug fixes:
| Certain objects of symmetry had erroneous angle values, off by small
decimal amounts. Such error propagated over time, making the objects
inaccurate and unattractive. This has been repaired and they work
correctly now. |
2003-11-26 Bug fixes:
| Inconsistent behavior in the Navigator has been repaired.
Holding your mouse over a generator while a Cayley diagram is animating
will now bring up a preview when highlighting completes. Pressing
more than one generator key at once now responds in a sensible way. |
| The version information in the program are now correct. |
| The Diagram Options dialog box now behaves correctly with respect to
generators. Formerly, if generators were removed from the diagram
and the changes committed by clicking "OK" to close the dialog box, it
would permanently forget about those generators. |
| Nodes now organize themselves correctly in diagrams with
close-together nodes. |
| All cylindrical diagrams now arc their arrows appropriately.
Formerly, certain sets of axes did not arc appropriately. |
2003-10-04 New features:
| The Change Diagram dialog box for Cayley diagrams can now reorganize
your diagram by any subgroup H defined and highlighted using the
Highlighter tool. This can be very useful when investigating
subgroups, testing for normality. More documentation on the use of
this feature will be added to the web site in days to come. |
| New axes available for auto-generated Cayley diagrams: Ring of lines,
Ring of circles, Ring of rectangles, Ring of polars, Ring of hollow
cylinders, Ring of tori, Ring of rectangular solids, and Ring of
cylinders. To be consistent, the axes Hyper-rectangular and
Hyper-cylindrical have been renamed to Line of rectangular solids and Line
of cylinders, respectively. |
| Improved automatic assignment of axes to generators to be a bit more
aesthetically pleasing in certain circumstances, namely circumstances with
more than one circular axis. |
2003-10-02 Bug fixes:
| The group Z2 x Z3 x Z3
x Z4 was misnamed in the Group
Library. This has been fixed. |
| Cylindrical axes now arc at all places in which the user would like
them to arc. |
| Toroidal axes (and others with varying circle centers) now arc in the
manner the user would expect. |
| Diagram Options tool now obeys the user's assignment of axes to
generators explicitly. (It formerly permuted the user's input
needlessly.) |
2003-09-23 New features:
| Group Explorer can now export 3D versions of Cayley diagrams and
objects of symmetry as VRML worlds! This option is available from
the File menu, "Save as VRML world..." and it outputs files with the
extension .wrl. A VRML viewer (e.g.
Cortona) is
required to view VRML worlds, and it can be used as a plug-in in your
browser. To see some example Cayley diagrams as VRML worlds, refer
to the Preview column on our Groups page. |
| The Highlighter for Cayley diagrams can now highlight the commutator
subgroup, and individual elements. |
| The Highlighter for Cayley diagrams has had several features that it
highlighted "by shape," i.e. distinguishing different classes of nodes by
the shapes it gave them. It can now do those same highlightings
either by shape or by color. Although in some cases it can be more
informative to highlight by shape (e.g. order classes have polygons with a
number of faces equal to the order), it is usually much more visually
helpful to highlight by color. For some very pretty examples, try
opening A5 and viewing the soccerball Cayley diagram,
and highlighting the left cosets of < (0 1 2 3 4) > by color; then
try the right cosets. |
| The Highlighter for Cayley diagrams now records the most recent
highlighting done on it, so that you can return to it by clicking a "Last
Highlighting" button, much like the "Last channel" button on TV remote
controls. This allows you to jump back and forth between two
interesting highlightings. |
| Object of symmetry views are now only allowed to be resized as
squares. That is, the "aspect ratio" for such views must be 1:1.
This way, someone who has designed an object of symmetry (say, a square)
that relies on its views not distorting the object, can depend on Group
Explorer to make good those assumptions about reasonable viewing
dimensions. |
| The dialog boxes that the user occasionally brings up to edit or
change properties now appear in the most convenient place available.
Most notably, the Highlighter and the Change Generation dialog box try to
always position themselves just to the right of the Cayley diagram in
view. |
2003-09-23 Bug fixes:
| The program's "description" (which Microsoft Windows Explorer displays
at various times) has been shortened, from the cumbersome "Program for
exploring mathematical objects called 'groups'" to "Group Explorer."
It seems "description" is not a good description of that field. |
| The default viewing angle for objects of symmetry has been slightly
modified to allow better vision of things like the cube with
superdiagonals (objects of symmetry for S4).
Reported by Eric Wilson |
The official first version!
Note that we've made MANY improvements to our website!
Check out especially the Lessons Page and its
subpages--ideas, assignments, and illustrated mini-lessons are being added
reguarly!
About six weeks have been dedicated to simply listening to bug reports
and fixing them, not adding new features. Very few have been found,
and all have been fixed. They are listed below, and their repair is
the reason we're now at v1.0.0 instead of v0.9.1:
2003-09-13 Bug fixes:
| In large groups, errors occurred when adding and removing arrows from
Cayley diagrams, in the Change Generation dialog window. Those bugs have
been fixed. |
| Errors would occur if a group had a generator bound to the "C" key on the
keyboard and the user closed the group with "Control-C" on the keyboard.
The program tried to perform a group operation as it was closing the group
and...well, it's fixed now. |
| The colors on the vertices of the square, the symmetry object for D4,
did not respect the colors in the permutation view. (This is somewhat of
an aesthetic "bug.") They do now; the file D_4.gp is
updated in the Group Library and in the distribution
.zip for v1.0.0. |
| Runtime errors that occurred when removing all the arrows from a Cayley
diagram using the Change Generation dialog window no longer occur. |
| Runtime errors that occurred when reprioritizing generators in the Change
Generation dialog window for a Cayley diagram no longer occur. |
2003-09-11 Bug fixes:
| The Group Library (and also the distribution
.zip) lacked the group Z2 x Z4.
Thus a new file Z_2 x Z_4.gp has been created and added to both,
in the interest of having a complete library of groups at least up to order
20. |
| The "circle homes" checkbox on the popup menu on objects of symmetry did
not always accurately reflect the state of the diagram. This bug has
been fixed. |
| The colors on the vertices of the triangle, the symmetry object for S3,
did not respect the colors in the permutation view. (This is somewhat of
an aesthetic "bug.") They do now; the file S_3.gp is
updated in the Group Library and in the distribution
.zip for v1.0.0. |
This version includes no change (since version 0.9) to the Group
Explorer executable itself, but includes the following corrections to the
library of groups distributed with the software. These same changes
are reflected in our Groups page.
2003-08-14 Correction:
| The group formerly labeled T, after Hungerford's notation, is
actually the semidirect product of Z3 with
Z4, and has been renamed appropriately.
Reported by Eric Wilson |
| Typo in group library listing
Z_3 x Z_3 sdp Z_2.gp with the wrong description has been
corrected. (It is the semidirect product of Z3
cross Z3 with Z2.)
Reported by Eric Wilson |
This is good news! It means the only bug reports coming in
now are easy to fix and not centered on the software itself. There
are a few software changes I may make before version 1.0, but either way,
we'll be ready for version 1.0 soon!
This version includes the following enhancements or repairs over
version 0.8.5:
2003-08-01 Correction:
| The .gp files were not completely up-to-date in the v0.9
release. My apologies. If you fetch v0.9 now, they are
up-to-date. |
2003-07-18 New features:
| The Cayley diagram menu no longer has cryptic ordered pairs among its
items (i.e. no more "Polar 0:1"). (These formerly enumerated all the
possible polar Cayley diagrams.) Now there is only one diagram of
each type by default, and once the user has brought it up, to change its
settings (i.e. to regenerate the polar diagram a new way with the same
generators) the user can right-click on the diagram and choose "Change
generation." This allows the user to explicitly set the priority for
the generators and their assignment to axes. By default, Group
Explorer tries to pick a decent default priority and assignment. |
| The axes "hyper-rectangular" and "hyper-cylindrical" are now
available. |
| The "Change generation" dialog described above also has the option to
add or remove generator arrows from the Cayley diagram. So if the
user wishes to keep the same diagram structure but see different
connecting lines, they have total freedom to do so. Note that this
feature applies to both custom and auto-generated Cayley diagrams, but the
previous feature applies only to the latter. |
2003-07-24 Bug fix:
| There were several very subtle errors in the auto-generation of Cayley
diagrams. "Very subtle" means that in the first 50 groups I created,
they didn't show up. Then I found a group that threw my algorithms
for a loop, and spent a week revamping them. They should work in all
cases now. The specific problem case was the new generators for S4,
(01), (1 2), and (2 3). |
This version includes the following enhancements or repairs over
version 0.8:
2003-07-16 Groups added:
| The group A5 has been added to the group
distribution. It is particularly nice because of the beautiful
relationship of its objects of symmetry to its Cayley diagrams, mirroring
those of S4 and A4 (truncated and
regular icosahedra and dodecahedra). |
| The Groups page of this website now has all
the groups listed on it for individual downloading and/or perusal. |
| The quaternion group Q4 was improved with some old
custom Cayley diagrams for it I had lying around and some new ones Ken
Monks concocted. |
| The cyclic groups Z2 through Z20
are now more aesthetically pleasing. |
| Some groups whose nice versions I meant to include with v0.8 but
forgot to now have their nice versions included here--specifically I said
that A4, S4, and V4
were improved in the last version (and they were) but I just forgot to
post the new copies at first. |
This version includes the following enhancements or repairs over
version 0.7:
2003-07-10 Bug fixes:
| Some oversights in saving and loading of default viewing options
have been corrected. |
2003-07-11 Bug fixes:
| Some uninformative error messages during group loading have been improved
(now showing permutations instead of simply their indices). |
2003-07-10 New features:
| Ability to circle the home sites of each node in an object of
symmetry, so the user can tell what the object's original orientation
was. (See the popup menu for objects of symmetry, the "Circle
Homes" option.) |
| The number of degrees of rotation for a specified action on an
object of symmetry can now be fractional. This is important
because in situations like wanting to rotate by one-seventh of a circle,
the appropriate number of degrees is approximately
51.428571428571428571428571428571, and if one is only allowed to type
"51," then the error propagates, and the symmetry object will be very
clearly not aligned after several manipulations. |
| Colors in .gp files can now be specified in either the
(original) RGB vector format, or by their (new) hue format, indexed
between 0.0 and 1.0, orderly progressing through the rainbow. For
example, Node1 = <1,1,1> Hue0.5 2 would create a radius-2
cyan-colored node at the point <1,1,1>. Hue 0.0 is red,
progressing through orange, yellow, green, blue, indigo, violet, and
back to red at 1.0 again. Note that the program uses the hue
indexed with a/b for the ath circle
(out of b) in the permutation view window, so labeling your points with
hue in this fashion (0/b, 1/b,
..., b-1/b) will guarantee they match up
appropriately with the permutation view. You can see now how
naturally and intuitively the cyclic and dihedral groups (as well as the
groups A4, S4, and V4)
match their objects of symmetry's colors with those in the
permutation view. |
| You can now use the color words Red, Orange, Yellow, Green, Blue,
Indigo, Violet, Black, and White instead of typing RGB vectors in
.gp files. |
2003-07-11 New features:
| The popup menu for a Cayley diagram now gives more than two options for
arrowhead placement. Before, it was simply a "Center Arrowheads" check
mark, with the arrowheads landing at the endpoint if the menu item was
unchecked. Now it is a submenu with three options: Center, Two-thirds,
and Endpoint, which give the expected behavior. This is sometimes useful
when directional lines cross at their midpoints, so arrowheads don't pile up
on one another. |
2003-07-12 New features:
| Cayley diagrams now respect the arcs when previewing and animating a
motion. Formerly, the preview and the motion of the grey circle in
Cayley diagrams followed a straight line path; now it follows the shape of the
arc, straight or curved, as appropriate. Requested
by Brad Emmons |
| Flicker is now gone when the user drags or uses Cayley diagram views and
when the user manipulates objects of symmetry. |
| The user now has the option in Cayley diagrams of placing the labels in
front of or behind the diagram itself (or of removing the labels altogether,
as usual). Requested by Ken Monks |
This version includes the following enhancements or repairs over
version 0.6.6:
2003-07-08 New features:
| Generators and Representation menus now have radio check dots to
indicate which item is selected. |
| Popup menus for Cayley diagrams and objects of symmetry now have a
"Set defaults to these" option. Clicking this menu item tells the
program to remember the settings for that window, so that when it
creates a new Cayley diagram/object of symmetry, it should initialize it
with those options. Requested by Ken Monks |
| The software now saves information about the way it is used (like
screen position and arrangement, as well as the default options
mentioned in the previous bullet) in an .INI file, so they
are preserved from one use of the program to the next. |
| The program now responds to a single command line argument of a
.gp filename, so if the user wishes to associate Group
Explorer with files that end in .gp, then double-clicking
those files will open them in the software. |
| Although I'm the only one who can see it, during all of the above
enhancements, I reorganized the code to remove several stupid kludges,
so future enhancements can be natural, as opposed to hacks. |
| The distribution now ships with all groups of orders up to and
including 20. (That's 54 groups!) |
Also, if you haven't checked out the other portions of this web site
recently, note that the Lessons page is quite
extended since version 0.6.6.
(The "Advanced" page has had some technical errors pointed out and fixed
also, but they are very minor.)
This version includes the following enhancements or repairs over
version 0.6.5:
2003-07-07 Bug fixes:
| Previewing operations in large groups now works without logic
errors. Version number now correct in the Group Explorer
application's menus and captions. Reported
by Ken Monks |
| Arrowheads drawn on operation previews now look more sensible. |
2003-07-07 New features:
| Custom Cayley diagrams now appear at the top of the "Create Cayley
diagram" submenu. Requested by Ken Monks |
This version includes the following enhancements or repairs over
version 0.6:
2003-07-03 Bug fixes:
| Groups embedded in symmetric groups S13 and higher now
work without runtime errors. |
2003-07-03 New features:
| When defining an object of symmetry in a .gp file, you
can now write Line declarations using references to Nodes, rather than
absolute coordinates. For example, Line1 = Node1 Node2
<0,0,0> 0.0 N. |
| Auto-generated Cayley diagrams now support toroidal and
hollow-cylindrical axes. |
| Also note that the library of groups that comes with the software is
vastly increased! The Group Explorer project aims to include all
groups up to order 20, plus some additional groups of higher order.
Right now it includes nearly all groups up to and including order 16. |
This version includes the following enhancements or repairs over
version 0.5.2:
2003-07-01 Bug fixes:
| Runtime errors during loading of product groups corrected. |
| All of a group's elements now appear on the Group Information
screen, whereas in version 0.5.2 the last few sometimes did not appear. |
2003-07-01 New features:
| Cayley diagram views now preview actions before you take them (as
symmetry object views always have) and Cayley diagram views are now
animated rather than instantaneous (again, as symmetry object views have
always been). |
| Names of elements specified in .gp files (when defining
representations of type "Generators" or "Table") can now include plus (+)
and minus (-) symbols. This expands the legal
character set to all letters and numbers, and plus and minus, as well as
underscore (_) and caret (^). |
Also, if you haven't checked out the other portions of this web site
recently, note the following recent additions:
| Many new assignments have been posted on the
Lessons page. |
| A Maple worksheet to help you create objects of symmetry for your
custom .gp files has been contributed to
the Advanced page by Ken Monks. |
This version includes the following enhancements or repairs over
version 0.5.1:
2003-06-30 Bug fixes:
| Inaccuracies in highlighting conjugate subgroups have been repaired.
Reported by Brad Emmons. |
2003-06-28 New features:
| Group menu has a "Group Info" choice which gives detailed
information about the current group. |
This version includes the following enhancements or repairs over
version 0.3:
2003-06-30 Bug fixes:
| If a list of generators for a group is redundant, the program now
does not balk, but rather just ignores the superfluous ones, except when
drawing arcs in Cayley diagrams. Reported by
Ken Monks |
| When the user creates a new Cayley diagram or object of symmetry
child window, the behavior is acceptable even when all child windows are
maximized. (Formerly the software did not respect the maximization, but
gave undesirable window positioning.)
Reported by Ken Monks |
| When the user changes the generators using the Group menu, the
example elements in the representation submenu change to reflect it.
Symmetrically, when the user changes the representation using the Group
menu, the representations of all elements in the generators submenu
change to reflect it. |
| When loading a group file, if a Cayley diagram neglects to mention a
group element, or mentions an element that is not in the group, an error
is reported and the group will not load. |
| Error in representing elements of large permutation groups (e.g. S8)
fixed. Reported by Ken Monks |
| When the user changes the group representation, all child windows
get refreshed to reflect the change.
Reported by Brad Emmons |
| When loading a group file, the program tests to see if all given
sets of generators generate the same group. If not, it gives an error
and refuses to open the group. |
| When loading a group file, if a representation is defined from
generators, the program tests to see if the generators given generate
the group they claim to represent. |
| When saving an image file, Group Explorer now prompts/warns before
overwriting an already-existing file. |
2003-06-27 New features:
| Mouse button on the Navigator for resetting a group, and an Apply
button on the Highlighter for more immediate investigation.
Requested by Ken Monks |
This version includes the following enhancements or repairs over
version 0.3:
2003-06-24 New features:
This version included the following enhancements or repairs over beta
testing versions:
2003-06-23 Bug fixes:
| The following bug was fixed in GroupExplorer_v0.3 and the new
version is now downloadable above: Arrowheads on arced arrows in Cayley
diagrams faced the wrong direction if and only if the arrowhead was
centered. Reported by: Ken Monks |
No earlier downloads
Earlier versions of Group Explorer were beta versions and are thus not
posted here.
|
