Mathematical Expressions in Import Scripts

The commands calc and emit in data extraction scripts may contain a mathematical or logical expression. This expression is not case sensitive. An expression may contain any number of user-defined variables, provided that the variable names are not equal to any of the reserved function names (see below). A user-defined variable always starts with a letter and may consist of any number of digits and letters and the underscore character ('_').

Care should be taken to avoid improper mixing of boolean and arithmetic subexpressions, for example:

(a>5) and (b=0) yields a boolean result, while
(a+5) and (b=0) yields an integer value (the and operator is used as a bitwise and)

The expression may use the following pre-defined constants, operators, and functions:

--- Constants ---
true	logical true (or -1, if used as number)
false	logical false (or 0, if used as number)
pi	the number Pi (3.14159...)
--- Arithmetic Operators ---
+	sum: x+y
-	difference: x-y
*	product: x*y
/	division: x/y
#	modulo: round(x) mod round(y)
^	power: exponentiation x^y , x>0, y..any real values
--- Logic Operators ---
>	greater than
>=	greater than or equal
=	equal
><	not equal
<	less than
<=	less than or equal
and	boolean or bitwise and
not	boolean or bitwise not
or	boolean or bitwise or
xor	boolean or bitwise exclusive or
--- Functions ---
abs	absolute value: abs(x), x..any real value
arccos	inverse cosine: arccos(x), x..angle in radians
arcsin	inverse sine: arcsin(x), x..angle in radians
arctan	inverse tangens: arctan(x), x..angle in radians
cos	cosine: cos(x), x..angle in radians
exp	exponential function: exp(x)
frac	fraction: frac(x) = x - int(x)
gauss	gauss creates normally distributed random numbers with zero mean and unit standard deviation
int	round towards zero: int(x)
lg	decadic logarithm: lg(x)
ln	natural logarithm: ln(x)
max	returns the maximum of a list of columns or rows; max(list), the list contains a list of columns or rows separated by commas; a range of neighboring columns/rows may be abbreviated by the ':' sign. The list may contain constant values, as well. Example: max(c3,c5,100) calculates the maximum of the columns 3 and 5 and the value 100 (i.e. whenever both the column 3 and the column 5 contain a value below 100 the function returns a value of 100).
mean	returns the mean of a list of variables: mean(list), with list containing a list of variables separated by commas; a range of numbered variables may be abbreviated by the ':' sign (i.e. "xx8:11" expands to "xx8, xx9, xx10, xx11").
min	returns the minimum of a list of columns or rows; min(list), the list contains a list of columns or rows separated by commas; a range of neighboring columns/rows may be abbreviated by the ':' sign. The list may contain constant values, as well. Example: min(c2:4,c7) calculates the minimum of the columns 2, 3, 4 and 7.
nddens	density of the standard normal distribution: nddens(x)
ndint	integral of the standard normal distribution from -infinity to x: ndint(x)
ndquant	quantile of the standard normal distribution for a probability x: ndquant(x)
rand	uniformly distributed random numbers: random(x), x..amplitude of noise (mean = 0.0)
round	round to the nearest integer: round(x)
sign	sign of x: sign(x)
sin	sinus: sin(x)
sqr	square: sqr(x)
sqrt	square root: sqrt(x)
sum	returns the sum of a list of variables: sum(list), with list containing a list of variables separated by commas; a range of numbered variables may be abbreviated by the ':' sign (i.e. "zz1:3" expands to "zz1, zz2, zz3").
tan	tangens: tan(x)
var	returns the variance of a list of variables: var(list), with list containing a list of variables separated by commas; a range of numbered variables may be abbreviated by the ':' sign (i.e. "xx8:10,aux4,y1:3" expands to "xx8, xx9, xx10, aux4, y1, y2, y3").

Hint:

Please note that the mathematical expressions available for import scripts are quite similar to the expressions used for Math Transformations, except for predefined constants and variable identifiers.