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Maxima-Mode

The userinterface can be switched to Maxima-mode during a running session by selecting the menuoption Run - Maxima Mode and back to Octave-mode by selecting Run - Octave Mode. All variables keep their values; they can be cleared if required by clicking Run - Clear Environment. Normally Jasymca starts up in Octave-mode; see chapter 5 for instructions on how to start up in Maxima-mode.

Not only do the two user-interfaces differ in grammar and semantics regarding some operators and functions (see chapter 4 for an overview): In Maxima-mode, symbolic variables need not be declared as such by syms. Jasymca automatically creates symbolic variables for each unknown character sequence. Return values are automatically assigned to variables named d1,d2,d3,.., and remain accessible throughout the session. These two features make Maxima-mode favourable for work with symbolic expressions, since few variables need to be declared. It is less suitable for large amounts of data since each intermediate result is saved, and fills up memory.

Some random examples follow. Commands in Maxima-mode must be concluded with a semicolon and may extend beyond several lines, i.e. hitting ``return'' without the semicolon leaves Jasymca waiting for more input.

c1) [2,3,4]+[4,5,6];     % semicolon!
    d1 = [ 6  8  10 ]    % automatic variable d1
(c2) d1[2]*d1[3];        % index in brackets
    d2 = 80                 
(c3) x^2+3 = y*x-2;      % automatic symbolic vars
    d3 = -x*y+(x^2+5)    % equations are differences
(c4) choose(n,k):=n!/((n-k)!*k!);  % defining functions
choose
(c5) sum(1/k^2,k,1,1000);% 2. version of sum
    d4 = 1.6439
(c6) allroots( (x-1)^3*(x-2)^2*(x-3)*(x-4) );
    d5 = [ 4  3  2  2  1  1  1 ]
(c7) allroots(x^2+1);
    d6 = [ 1*i  -1*i ]
c8) a:x+2-y;           % assignment with ':'
    a = -y+(x+2)

Working with m-files is not supported, therefor all functions loaded by this mechanism do not work in Maxima-mode. Working with vectors and matrices is also less comfortable: While the builtin functions (determinante, inverse, LAPACK-functions, etc) are available, the conveniant methods for indexing, extraction and insertion ( colon operator) are not supported.

Working with files is accomplished using the loadfile und save- functions, or the menu-fileoptions.


next up previous contents
Next: Reference Up: Jasymca 2.0 - Symbolic Previous: Differential Equations
Helmut Dersch
2009-03-15