Kepler

It is almost never a good idea to compare doubles without using an epsilon factor. Because of rounding, doubles are unlikely to precisely represent a value.

One workaround in the expression language is to use

close(value1, value2)

which is defined as:

Return true if the first argument
is close to the second (within
EPSILON, where EPSILON is
a static public variable of this
class)

Tokens also have an isCloseTo() method:

/** Test whether the value of this Token is close to the argument * Token. The argument and this token are converted to * equivalent types, and then compared. Generally, this is the * higher of the type of this token and the argument type. * Subclasses should implement the protected _isCloseTo() method * to perform the correct type-specific operation. * @see #isEqualTo * @param rightArgument The token to test closeness of this token with. * @param epsilon The value that we use to determine whether two * tokens are close. * @return A boolean token that contains the value true if the * units of this token and the argument token are the same, and their * values are close. * @exception IllegalActionException If the argument token is not * of a type that can be compared with this token, or the units * are not the same.
*/
public final BooleanToken isCloseTo(Token rightArgument, double epsilon)

See 13.4.1 Invoking Methods in http://ptolemy.eecs.berkeley.edu/books/Systems/chapters/Expressions.pdf