Formula: Errors

QFFE_103: "Illegal symbol 'symbol' in formula"

Syntax error in formula - illegal symbol found in formula text.

Cause

Formula contains either control or graphical character or a character from an unsupported character set.

Examples:

• Illegal symbol

  5 · t	Illegal symbol '·' in formula
  30% * 1000ˆ	Illegal symbol '%' in formula

• Brackets used instead of parentheses.

  [1 - sin(t)]

  Illegal symbol '[' in formula

• Operator omitted.

  3t + 1	Illegal symbol 't' in formula
  2cos(t)	Illegal symbol 'c' in formula
  2 cos(t)	Illegal symbol 'c' in formula

• Space in a constant or a name.

  3. 14	Illegal symbol '1' in formula
  1 234.56	Illegal symbol '2' in formula

• Two exponent symbols (e) in a floating-point number

  1e+3e

  Illegal symbol 'e' in formula

Resolution

• Remove anything besides letters, digits and characters '+', '-', '*', '/', '^', '(', ')', ','(comma), '.'(point), '"'(quotation mark) from the formula.
• Remove unneeded spaces.
• Remove group separators from numbers.
• Use point ('.') as decimal separator.
• Replace all kinds of grouping delimiters (e.g. brackets and curly braces) with parentheses.
• Check that all names of functions and predefined variables and constants is correct.
• Check formula syntax.