Differences between revisions 3 and 6 (spanning 3 versions)
Revision 3 as of 2008-11-25 21:35:57
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Editor: BurcinErocal
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Revision 6 as of 2009-02-05 15:27:20
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Editor: BurcinErocal
Comment:
Deletions are marked like this. Additions are marked like this.
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 * evaluation === remaining items ===
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 * print order (William's list)
{{{
Now,
sage: x^2 + x^4 + x^3
x^2 + x^3 + x^4
sage: a^3*x^10 + x^12 - a^15
x^12 + a^3*x^10 - a^15
So it is printing from lowest to highest degree, like mathematica (or power series),
but unlike the standard sage convention (or maple, singular, MATH, etc.):
sage: R.<a,x> = QQ[]
sage: a^3*x^10 + x^12 - a^15
-a^15 + a^3*x^10 + x^12
sage: singular(a^3*x^10 + x^12 - a^15)
-a^15+a^3*x^10+x^12
}}}
 * 1/gamma(-1) = 0
 * collect_common_factors (William's list)
{{{
need to be able to do this (from ginsh):
> collect_common_factors(x/(x^2 + x));
(1+x)^(-1)
}}}
 * pretty printing (latex() method, a/b instead of a*b^{-1}, etc.)
Line 50: Line 27:
 * callable symbolic expressions??
Line 53: Line 29:
=== long term ===
 * find a better scheme for handling compare()

=== in progress ===

 * Arithmetic with infinity (almost done)
 * Series expansions

=== done ===
 * 1/gamma(-1) = 0

==== Sage 3.3 - pynac-0.1.2 ====
 * symbolic binomial and factorial
 * iterator for sage.symbolic.expression.Expression
 * operator method
   (similar to current _operator(), but returns the function if the expression is a function application)
{{{
sage: var('x,y,z,n,i,j',ns=1)
(x, y, z, n, i, j)
sage: sin(x).operator()
sin
sage: type(sin(x).operator())
<class 'sage.calculus.calculus.Function_sin'>
sage: factorial(n).operator()
factorial
sage: type(factorial(n).operator())
<class 'sage.calculus.calculus.Function_factorial'>
}}}
 * evaluation
  Substitution for more than variable done, call semantics/syntax needs more thought
 * print order (William's list)
{{{
This text was a part of William's original todo notes, perhaps now it's confusing to include it here.

Now,
sage: x^2 + x^4 + x^3
x^2 + x^3 + x^4
sage: a^3*x^10 + x^12 - a^15
x^12 + a^3*x^10 - a^15
So it is printing from lowest to highest degree, like mathematica (or power series),
but unlike the standard sage convention (or maple, singular, MATH, etc.):
sage: R.<a,x> = QQ[]
sage: a^3*x^10 + x^12 - a^15
-a^15 + a^3*x^10 + x^12
sage: singular(a^3*x^10 + x^12 - a^15)
-a^15+a^3*x^10+x^12
}}}
 * collect_common_factors (William's list)
{{{
need to be able to do this (from ginsh):
> collect_common_factors(x/(x^2 + x));
(1+x)^(-1)
}}}
 * pretty printing (latex() method, a/b instead of a*b^{-1}, etc.)
 * callable symbolic expressions

TODO list for the pynac interface

"fully get rid of maxima-based symbolic variables"

remaining items

  • support for _fast_eval
  • hash is random
  • pyobject deallocations, memory leaks
  • noncommutative symbols
  • symbol domains (ginac supports real, complex, integer)
  • precision for numeric evaluation (evalf, _mpfr_, William's list)

genuine coercions to real field, etc.
  • pickling (William's list)

Support pickle via the "archive" print mode.
  • gcd (William's list)

Maybe change SAGE's Ginac to make a call to a cython gcd function, then use
singular, since singular's gcd over QQ is much better than ginac's, I think,
and ginac *only* does GCD over QQ.  Actually, just make everything in normal.cpp
be implemented via Singular, probably...
  • unevaluated expressions?
  • piecewise expressions, substitution and pattern matching

long term

  • find a better scheme for handling compare()

in progress

  • Arithmetic with infinity (almost done)
  • Series expansions

done

  • 1/gamma(-1) = 0

Sage 3.3 - pynac-0.1.2

  • symbolic binomial and factorial
  • iterator for sage.symbolic.expression.Expression
  • operator method
    • (similar to current _operator(), but returns the function if the expression is a function application)

sage: var('x,y,z,n,i,j',ns=1)
(x, y, z, n, i, j)
sage: sin(x).operator()
sin
sage: type(sin(x).operator())
<class 'sage.calculus.calculus.Function_sin'>
sage: factorial(n).operator()
factorial
sage: type(factorial(n).operator())
<class 'sage.calculus.calculus.Function_factorial'>
  • evaluation
    • Substitution for more than variable done, call semantics/syntax needs more thought
  • print order (William's list)

This text was a part of William's original todo notes, perhaps now it's confusing to include it here.

Now,
sage: x^2 + x^4 + x^3
x^2 + x^3 + x^4
sage: a^3*x^10 + x^12 - a^15
x^12 + a^3*x^10 - a^15
So it is printing from lowest to highest degree, like mathematica (or power series),
but unlike the standard sage convention (or maple, singular, MATH, etc.):
sage: R.<a,x> = QQ[]
sage: a^3*x^10 + x^12 - a^15
-a^15 + a^3*x^10 + x^12
sage: singular(a^3*x^10 + x^12 - a^15)
-a^15+a^3*x^10+x^12
  • collect_common_factors (William's list)

need to be able to do this (from ginsh):
> collect_common_factors(x/(x^2 + x));
(1+x)^(-1)
  • pretty printing (latex() method, a/b instead of a*b^{-1}, etc.)
  • callable symbolic expressions