GroupJep Console Example Applet

The JEP Java Expression Parser can parse and evaluate mathematical expresions. The DJep package adds differentation, simplification vectors and matricies, abstract groups and several other advanced features.

Below is a console for the GroupJep part of the DJep package, which adds exact arithmatic over abstract groups.

Groups

Various groups are available:
group Zintegers (full precision)
1*2*3*4*5*6*7*8*9*10*11*12*13*14*15*16*17*18*19*20 -> 2432902008176640000
group Qrationals
1/3-1/4 -> 1/12
group Rreals, represented as Doubles.
group R 3reals reprecented as BigDecimals with 3 decimal places
group P 3permutation group on three symbols
[1,3,2]+[3,2,1] -> [3,1,2]
group Zn 5integers modulo 5
3+4 -> 2
group QuQuartonians
i*j -> -k
extend xextends current group by adding symbol x, i.e. a free group. Such a group can be considered as the ring of polynomials simplification happens automatically.
group Z
extend x
(x-1)^3 -> x^3-3 x^2+3 x-1
extend t a b calgebraic extensions generated by t where t is a root of the polynomial a t^2 + b t +c=0 e.g 'extend t 1 0 1' gives complex numbers, t^2+1=0. for these groups there is a natural mapping to complex numbers and complex result is also printed.
group Z
extend t 1 0 -2  # Z[sqrt(2)]
(t+1)^2 -> 2 t+3

group Z
extend t 1 -1 -1 # Z[t^2-t-1, t = tau]
t^2 -> t+1

Other Demos

Copyright

The DJep (org.lsmp.djep.*) portions of the package is copyright Richard Morris (c) 2005. rich@singsurf.org. The org.nfunk.jep parts are by Nathan Funk (c) 2005. Both parts dual licensed under the GNU General Public License and a commercial license.

This code (i.e. org.lsmp.djep.*) is covered by a Creative Commons Attribution, Non Commercial, Share Alike license License and is copyright Richard Morris (c) 2004.

Home Page, DJep Home Page, JEP Home Page, Sourceforge project page, Documentation. © 2005 Nathan Funk and Richard Morris