Symbolic variables should not be confused with variables
as discussed until now. These latter variables serve as address
for an object in memory (the ``environment''), while symbolic
variables are algebraic objects on their own. That means if
x
is a conventional variable, entering x
in the
textinputfield makes Jasymca search in the environment for
the corresponding object, which then replaces x
.
If however x
is a symbolic variable, the same action will
lead to the creation of a first-degree polynomial with variable x
and coefficients 1 and 0.
In Octave-mode, each symbolic variable x
must be declared
as symbolic by entering syms x
before using it. The command
clear x
deletes the symbolic (actually any) variable x
.
>> x=3; % nonsymbolic variable >> x^2+3-2*sin(x) % placeholder for '3' ans = 11.718 >> syms x % symbolic variable >> x^2+3-2*sin(x) % create function ans = -2*sin(x)+(x^2+3)