Assignments

An assignment stores the value(s) of an expression into a EXTREMA variable. An assignment has the form: variable = expression where expression is some combination of constants, variables, functions, and operators. For example:

 Y=A*COSD(X/10)+3.5*SIND(X/12)+C*EXP(-X)
 

The type of variable generated by an assignment is determined by the expression. If the right hand side of the assignment evaluates to a character string, the variable will be a character variable, while if it evaluates to a numeric value or values, the variable will be a numeric variable. In this case, the shape of the right hand side determines whether it is a scalar, vector or matrix. You can also mix numeric and character, in which case the result will be numeric. For example:

A = 2
B = 3
T = 'A+B'
C = 3*T

and C will be a numeric scalar variable with the value 15.

Input is limited to 255 characters, so to have expressions that are longer, use character variables to store its pieces and the EVALUATE function to evaluate the expression numerically. For example:

F1 = '2.5*COS(X/10)+3.5*SIN(X/12)+63.7*EXP(X/45)'
F2 = '1.234567*MOD(X,100)+SIN(X/1000)*EXP(X/200)'
F3 = '3.56789*X^2-2.34567*X+23.456'
F = 'F1+F2+F3'
Y = EVALUATE(F)

You can use the EXPAND function to expand all the parts of a string. For example, with the above variable definitions, =EXPAND(F) will display:

(2.5*COS(X/10)+3.5*SIN(X/12)+63.7*EXP(X/45))+(1.234567*MOD(X,100)+SIN(X/1000)*EXP(X/200))+(3.56789*X^2-2.34567*X+23.456)

  Expressions
  String assignments