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Revision 3716 - (view) (download) (as text) (annotate) - [select for diffs]
Modified Sun Oct 16 03:37:17 2005 UTC (14 years, 1 month ago) by dpvc
File length: 7819 byte(s)
Diff to previous 3525
In the past, when Value objects were inserted into strings, they would
automatically include parentheses so that if you had $f equal to 1+x
and $g equal to 1-x, then Formula("$f/$g") would mean (1+x)/(1-x)
rather than 1+(x/1)-x, which is what would happen as a straing string

The problem is that this would also happen for real numbers, vectors,
and everything else, even when it wasn't necessary.  So if $x=Real(3),
then "Let x = $x" would be "Let x = (3)".

I have changed the behavior of the string concatenation for Value
objects so that parentheses are only added in a few cases: for
Formulas, Complex numbers, and Unions.  This makes the other Value
objects work more like regular variables in strings, but might cause
some problems with strings that are used as formulas.  For example, if
$a = Real(-3), then "x + 2 $a" will become "x + 2 -3", or "x-1" rather
than the expected "x - 6".  (The old approach would have made it "x +
2 (-3)" which would have worked properly).  For the most part, it is
easier to use something like "x + 2*$a" or even "x" + 2*$a in this
case, so the extra trouble of having to avoid parentheses when you
really meant to substitute the value into a string didn't seem worth

Revision 3525 - (view) (download) (as text) (annotate) - [select for diffs]
Modified Sun Aug 14 00:23:10 2005 UTC (14 years, 3 months ago) by dpvc
File length: 7811 byte(s)
Diff to previous 3516
Added methods for testing containment of one set in another, and so
on.  These include:

     $A->contains($B)        Test if $B is a subset of $A (or an
                             element of $A if $B$ is a real number).

     $A->isSubsetOf($B)      Test if $A is a subset of $B.

     $A->isEmpty             True if $A is the empty set.

     $A->intersects($B)      True if $A and $B have numbers in common.

     $A->intersect($B)       The set of numbers common to both $A and $B.

Be careful of the difference between "intersect" and "intersects".
One is a set the other a true/false value.

Revision 3516 - (view) (download) (as text) (annotate) - [select for diffs]
Modified Sat Aug 13 20:59:28 2005 UTC (14 years, 3 months ago) by dpvc
File length: 7321 byte(s)
Diff to previous 3508
Added isSetOfReals and canBeInUnion methods to the Value objects, and
replaced the ad hoc tests for these conditions to call these

Cleaned up the make() methods for Intervals, Sets and Unions, and
improved the new() methods to handle more cases better.

Fixed Value::makeValue() to handle an array reference correctly.

I don't THINK any of this will break anything.  :-)

Revision 3508 - (view) (download) (as text) (annotate) - [select for diffs]
Modified Sat Aug 13 16:58:56 2005 UTC (14 years, 3 months ago) by dpvc
File length: 7326 byte(s)
Diff to previous 3497
Added isReduced method to tell if a Union, Set or Interval is already
reduced.  Fixed up sort to use CORE::sort, and added sort and reduce
to Intervals, which do nothing, but are there for consistency.

Revision 3497 - (view) (download) (as text) (annotate) - [select for diffs]
Modified Sat Aug 13 00:25:27 2005 UTC (14 years, 3 months ago) by dpvc
File length: 7201 byte(s)
Diff to previous 3487
Added ability for Unions and Sets to simplify themselves
(automatically or on demand), and added flags to the Context and
answer checkers to control these features.  The new Context flags

    reduceUnions                tells whether unions are automatically
                                reduced when they are created.

    reduceUnionsForComparison   tells whether unions are reduced
                                before comparing them for equality
                                or inequality (etc) if they aren't
                                reduced already.

    reduceSets                  tells whether redundent elements are
                                removed from sets as they are created.

    reduceSetsForComparison     tells whether sets are reduced before
                                comparing them.

All of these default to true.

The Interval, Set, Union, and List answer checkers not have two new
flags for controlling these values:

    studentsMustReduceUnions    tells whether unions and sets will be
                                counted as incorrect when they are not
                                reduced to non-overlapping intervals
                                and at most one set with no repeated

    showUnionReduceWarnings     tells whether an error message will
                                be produced for non-reduced unions and
                                sets, or if they will be marked wrong
                                silently.  (Not available in Lists.)

Both of these are true by default, since most professors probably want
their students to write intervals in reduced form.  (Is this true?)
This corresponds the the current behavior of the interval checkers,
which require the student's answer to be the same set of intervals as
in the professor's, but with the addition of an error message when the
student answer is not reduced.

Revision 3487 - (view) (download) (as text) (annotate) - [select for diffs]
Modified Fri Aug 12 17:09:42 2005 UTC (14 years, 3 months ago) by dpvc
File length: 7207 byte(s)
Diff to previous 3477
Changed how Intervals implement the requireParenMatch flag for the
interval and union answer checker.  (Use a Context flag rather than a
flag on the interval itself.)  Moved the getFlag method from
Formula.pm to Value.pm so it can be used by any object class.  New
feature where classes can add more context flags to set (and reset
after the answer checker runs).

Revision 3477 - (view) (download) (as text) (annotate) - [select for diffs]
Modified Thu Aug 11 20:57:18 2005 UTC (14 years, 4 months ago) by dpvc
File length: 7153 byte(s)
Diff to previous 3471
Added ability to subtract intervals, sets and unions.  Adjusted the
precedence of the union 'U' to be above _ and + so that things like
(1,5) U (7,10) - {8} U (2,3) will do ((1,5) U (7,10)) - ({8} U (2,3))
rather than the previous (1,5) U ((7,10) - {8}) U (2,3).  Finally,
added a constant 'R' to the Interval context that is equivalent to
(-inf,inf), so you can do things like R-{0} now.

Still need to work out reducing unions so that things like (1,3)U(2,4)
can become (1,4).

Revision 3471 - (view) (download) (as text) (annotate) - [select for diffs]
Modified Thu Aug 11 14:28:07 2005 UTC (14 years, 4 months ago) by dpvc
File length: 6013 byte(s)
Diff to previous 3460
Changes needed for Set object, better handling of an interval given as
a string, and a few misc. fixes.

Revision 3460 - (view) (download) (as text) (annotate) - [select for diffs]
Modified Wed Aug 10 15:07:12 2005 UTC (14 years, 4 months ago) by dpvc
File length: 6746 byte(s)
Diff to previous 3370
Interval (and Union) checker now accepts requireParenMatch flag for
deciding whether the interval type must match.  Setting
requireParenMatch to 0 will let (1,2) match (1,2] or [1,2], etc.

Revision 3370 - (view) (download) (as text) (annotate) - [select for diffs]
Modified Tue Jul 12 22:29:53 2005 UTC (14 years, 5 months ago) by dpvc
File length: 6717 byte(s)
Diff to previous 3260
A first pass at making parser error messages localizable.  The
Context()->{error}{msg} hash can be used to specify translations of
the standard messages.  For example,

    Context()->{error}{msg}{'Division by zero'} = "Don't divide by zero, dude!";
    Context()->{error}{msg}{'Function '%s' has too many inputs'} =
        "You passed too many arguments to '%s'";

(I didn't translate into another language, here, but you could do
that, too.)

The msg hash could also be used within answer checkers to make certain
answer messages more appropriate for the given type of expected answer.

Revision 3260 - (view) (download) (as text) (annotate) - [select for diffs]
Modified Sat Jun 4 13:50:01 2005 UTC (14 years, 6 months ago) by dpvc
File length: 6718 byte(s)
Diff to previous 3192
Remove unneeded comment.

Revision 3192 - (view) (download) (as text) (annotate) - [select for diffs]
Modified Wed Mar 16 13:30:28 2005 UTC (14 years, 8 months ago) by dpvc
File length: 6786 byte(s)
Diff to previous 2800
Update the overloaded operators so that they can be overridden by
subclasses of the predefined object classes.  This involves calling
the objects method rather than using a hard reference to the routine
in the parent class.

Also, change the name of the string comparison routine to
compare_string to avoid conflicts with cmp that is used to produce the
answer checker for the class.

Finally, in Value.pm, promotePrecedence no longer has to do fancy
footwork to get "special" precedence to work (this was a hack to get
around the misfeature of the overloaded operators -- now that that is
being handled correctly, there is no need for it).

Revision 2800 - (view) (download) (as text) (annotate) - [select for diffs]
Modified Sun Sep 19 14:27:39 2004 UTC (15 years, 2 months ago) by dpvc
File length: 6713 byte(s)
Diff to previous 2678
Added isZero and isOne checks for Parser::Value objects (i.e., for
constants within formulas).  These now correctly handle vector and
matrices, in particular.  The isOne and isZero checks are used in the
reduce() method to simplify formulas.

Revision 2678 - (view) (download) (as text) (annotate) - [select for diffs]
Modified Mon Aug 23 23:55:37 2004 UTC (15 years, 3 months ago) by dpvc
File length: 6683 byte(s)
Diff to previous 2668
Modified the parser so that the classes for the various object
constructors are stored in the context table rather than hard-coded
into the parser.  That way, you can override the default classes with
your own.  This gives you even more complete control to modify the
parser.  (You had been able to replace the definitions of operators,
functions and list-like objects, but could not override the behaviour
of numbers, strings, variables, and so on.  Now you can.)

This effects most of the files, but only by changing the name of the
calls that create the various objects.

There are also a couple of other minor fixes.

Revision 2668 - (view) (download) (as text) (annotate) - [select for diffs]
Modified Sun Aug 22 02:55:38 2004 UTC (15 years, 3 months ago) by dpvc
File length: 6662 byte(s)
Diff to previous 2626
Fixed TeX output of Matrices to use \array rather than \matrix for
matrices with formulas as entries (this had already been fixed for
constant matrices).  Made intervals produce formulas when of of the
endpoints is a formula.  Removed unneeded comment.

Revision 2626 - (view) (download) (as text) (annotate) - [select for diffs]
Modified Mon Aug 16 19:44:26 2004 UTC (15 years, 3 months ago) by dpvc
File length: 6572 byte(s)
Diff to previous 2625
One more fix for handling intervals properly (I think it's really
right this time).  Also, named constants that end in numbers will
produce TeX output with the number as a subscript (this was already
true for variable names).

Revision 2625 - (view) (download) (as text) (annotate) - [select for diffs]
Modified Mon Aug 16 18:35:12 2004 UTC (15 years, 3 months ago) by dpvc
File length: 6482 byte(s)
Diff to previous 2621
Added string comparison to all Value object classes (to compare the
string value of an object to another string).

Overloaded perl '.' operator to do dot product when the operands are
formulas returning vectors.  (Part of the auto-generation of

A few improvements to real and complex class output results.

Made Union class slightly more robust and removed need for makeUnion
method other than in the Union itself.

Revision 2621 - (view) (download) (as text) (annotate) - [select for diffs]
Modified Sun Aug 15 17:05:41 2004 UTC (15 years, 3 months ago) by dpvc
File length: 6479 byte(s)
Diff to previous 2612
Improved error messages, particularly when the student enters a
formula in an answer that should be constant, and also for incorrect
answers in lists of answers.  There are a few other miscellaneous output
improvements as well.

Revision 2612 - (view) (download) (as text) (annotate) - [select for diffs]
Modified Sat Aug 14 19:29:42 2004 UTC (15 years, 3 months ago) by dpvc
File length: 6468 byte(s)
Diff to previous 2606
Fixed some bugs in the handle of the context in ->string and ->TeX
methods of Value objects.

Revision 2606 - (view) (download) (as text) (annotate) - [select for diffs]
Modified Sat Aug 14 11:25:47 2004 UTC (15 years, 3 months ago) by dpvc
File length: 6381 byte(s)
Diff to previous 2603
Can now specify that the objects stringify themselfs in their TeX
forms rather than their answer-string forms.  This makes it easier to
use the objects in the text of a problem (without having to call ->TeX
explicitly each reference).



to start outputting TeX strings, and


to switch back.

Revision 2603 - (view) (download) (as text) (annotate) - [select for diffs]
Modified Fri Aug 13 23:01:07 2004 UTC (15 years, 3 months ago) by dpvc
File length: 6309 byte(s)
Diff to previous 2601
Added an Infinite object class for the Value package.  Still need to
add it to the Parser package.

Revision 2601 - (view) (download) (as text) (annotate) - [select for diffs]
Modified Fri Aug 13 19:06:09 2004 UTC (15 years, 3 months ago) by dpvc
File length: 6341 byte(s)
Diff to previous 2596
Added ability to report incorrect coordinates in point and vector
answers, and incorrect endpoints and endpoint types in intervals.
Separated these kinds of checks from the typeMatch check, where they
didn't really belong.

Added ability to specify intervals and unions as strings in Interval()
and Union(), which makes it easier to make constants of these types.

There are still problems comparing intervals that contain infinities;
I really need to make the infinity object to solve this, so have put
off trying to fix that for now.

Revision 2596 - (view) (download) (as text) (annotate) - [select for diffs]
Modified Thu Aug 12 23:11:32 2004 UTC (15 years, 3 months ago) by dpvc
File length: 6092 byte(s)
Diff to previous 2594
Have parser handle infinities better.

Revision 2594 - (view) (download) (as text) (annotate) - [select for diffs]
Modified Thu Aug 12 20:17:18 2004 UTC (15 years, 3 months ago) by dpvc
File length: 5907 byte(s)
Diff to previous 2592
Fixes for handling intervals better.  In particular, deal better with
ambiguous situations, like (1,2) that could be a point.

You can use [a,a] to specify the single point a.  I'd like to make {a}
represent this (and maybe even {a,b,c} to form finite sets), but this
would interfere with the use of { and } as alternative parentheses.
(Does anyone really use these?)

Do we need a cross product for intervals (and sets) as a means of
representing regions in R^2 (or higher)?

Revision 2592 - (view) (download) (as text) (annotate) - [select for diffs]
Modified Thu Aug 12 16:40:47 2004 UTC (15 years, 3 months ago) by dpvc
File length: 5580 byte(s)
Diff to previous 2579
A number of small fixes.  Most were to fix minor bugs in string and
TeX output, particulary for the various list-based objects (like
vectors, intervals, etc.).  There were also some bug fixes in the
comparison routines.  Some additional checks were added for valid
intervals when the coordinates are formulas.

Revision 2579 - (view) (download) (as text) (annotate) - [select for diffs]
Modified Mon Aug 9 21:38:01 2004 UTC (15 years, 4 months ago) by dpvc
File length: 5530 byte(s)
Diff to previous 2558
Significant update to new parser.

New features include:

  Better control over format of vector output (you can now
    specify ijk-format rather than <...> format)

  "Fuzzy" reals, where the relations like == return true when the
    two values are "close enough".  (This is controlable using
    parameters similar to those used in NUM_CMP).

  The fuzzy reals are now used in vectors/points/matrices/complexes/intervals
    and so on so that their relations will also be fuzzy.  E.g.,
    (1E-13,2) == (0,3) will be true, and norm(Vector(0,1E-13)) will
    equal 0.

  The two main portions of the parser (the Parser and Value packages)
    now share a common context object for configuration purposes.

Revision 2558 - (view) (download) (as text) (annotate) - [select for diffs]
Added Wed Jul 28 20:32:33 2004 UTC (15 years, 4 months ago) by sh002i
File length: 5237 byte(s)
merged changes from rel-2-1-a1 -- stop using that branch.

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