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)

2009-03-15