wiki:MarkusHohenwarter
Last modified 14 months ago Last modified on 04/13/11 12:50:49

I started GeoGebra in 2001 and have been leading the project since that time. Today, I'm working as a professor for ​mathematics education at the Johannes Kepler University Linz, Austria.

Current project

I'm redoing Functions and adding multivariate functions

  • Derivative[g, y]
  • Integral[g, y]
  • f(x,y,z) = x + y + z
  • Derivative[x y, y], allow just "x + y" as input for a function
  • allow h(x, y) = g(x), j(x,y) = f(x,y) + h(x,y)
  • allow f(x) + g(x,y)
  • f(x,y) = If[x y > 0, x y, - x y]
  • function arithmetic, f + g
  • #198
  • #224
  • http://www.geogebra.org/forum/viewtopic.php?f=22&t=18349
  • check if AlgoSequence needs updating (look for isGeoFunction())
  • Curve[f1(r, s), f2(r, s), r, 0, 10]
  • complex functions

Winter 2010 TODO

Parser

  • support for sin(x+y) = 0 in case we do this in the future

New stuff

  • Threaded views to make e.g. LaTeX drawing faster
  • CAS: make sure functions are always in sync with CAS not just when CAS view is open, see CASview.add() et al. Test case: f(x) = x2, g(x,y) = f(x) + y, Derivative[g(x,y), x]
  • CAS: check binding/unbinding vars for Maxima
  • Copy & Paste, see Google Sketchup, stick to objects -> tessellations, think about support for "Paste Special" in spreadsheet
  • Locus from slider

CAS

Optional

  • Parser: |x| absolute value, |x-1|3|x-1|
  • Parser: g: X = A + t (B-A), r = a + λ b for lines in 3D (& 2D?)
  • Parser: r = sin(θ) polar coords -> convert to Curve[]
  • Tool bugs: maybe Zbyněk Konečný could help a bit

Tickets

GeoGebra 3.2 milestone tickets:

#79
problem when changing rounding
#273
file loads OK but then XML problem in applet

GeoGebra 4.0 milestone tickets:

#102
AlgoPointsFromList doesn't work when Point[ { {1,2}, {3,4} } ] is redefined
#159
add support for f:x→x^2 notation
#166
missing locus
#229
SolveODE[-x/y] - support needed for eg (-y²) / 2 = x² / 2 + const
#239
RecursiveSequence[ ] command
#324
allow function f(x) = Determinant[M-x*I]
#332
Root[ln(x) - x + 2] problem
#470
If command doesn't accept multi-variable statements
#515
auto-replace e^ with exp(
#625
problem with GeoElement.set() for GeoFunction (GeoFunctionNVar)
#640
Intersection undefined on reloading file
#933
redefine ray, loses properties
#980
using if(...) in the CAS creates a new function.
#1039
Probability Calculator's geos need to be made "invisible"
#1051
Protect constant and command names in MPReduce
#1074
Mac: double click ggb file will destroy unsaved construction
#1091
Path parameter lost (reset) in degenerate case
#1098
CommonDenominator[ ] problems
#1117
2 errors in Intersect functions
#1135
Speed up derivatives and intersections on dragging
#1158
arbconst(x)=x^2 needs to be disabled
#1159
mat, arbint need to be added to RESERVED_FUNCTION_NAMES
#1270
Numeric(sqrt(-5))
#1442
problem with 'z' in Sequence[Sequence[
#1478
Problem on renaming objects on Mac OS X

GeoGebra 4.2 milestone tickets:

#841
{{{{{{{{{{{{{{{{{{{{{{{{{{{{{{{{{{} extremely slow (minutes)
#1275
try to avoid CAS evaluations when a file is loaded
#1373
CAS efficiency on loading files
#1394
Solve[x=x] -> {x = arbconst(1)}
#1540
add direct input of polar functions
#1576
problem when variables used for function arguments and function definition
#1696
CAS algos in loci

GeoGebra 5.0 milestone tickets:

#10
parsing planes and lines equations
#60
parsing quadric equations
#464
Allow spreadsheet cells to be CAS objects
#638
x(A) x+y(A) y+z(A) z=0
#647
support for degrees/minutes/seconds input 12°12'22"
#669
naming objects "x"
#1000
World Domination
#1142
Unify internal function and command names
#1161
Make kernel.useTempVariablePrefix non-static
#1215
y(A-A) parsed badly
#1235
Line style of Locus is not working if the Locus is saved as and reloaded
#1327
redefining a polygon deletes segments