The Set Variable action allows you to compute a mathematical equation and store the result in a variable. The supported math syntax and functions are documented below.
Story Machine supports most common math operators: + - / * ( )
It also supports a few more technical operators:
- % - modulus, the remainder
- ^ - power
3 + (5 * 2^4) - (27 / 10)
Math functions and constants
Story Machine supports the following math functions. These are in the form of name(value).
- abs - absolute value
- acos - arccosine
- asin - arcsine
- atan - arctangent
- atan2(y,x) - computes the angle between the x axis and a line from the origin passing through (x, y)
- ceil - round up to the nearest whole number
- cos - cosine
- cosh - hyperbolic cosine
- exp - exponential value (e ^ x)
- fac - factorial
- floor - round down to the nearest whole number
- ln - natural log
- log - base 10 log
- ncr - combination (n, r)
- npr - permutation (n, r)
- pow - power (x ^ y)
- sin - sine
- sinh - hyperbolic sine
- sqrt - square root
- tan - tangent
- tanh - hyperbolic tangent
Story Machine also provides the following math constants, which can be used in equations.
- e - Euler’s number
- pi - Pi
- deg2rad - multiply with an angle in degrees to get radians
- rad2deg - multiply with an angle in radians to get degrees
- random - a random number between 0 and 1
- approach(value, target, change) - moves value towards target at rate change. Will not surpass target.
- clamp(value, min, max) - clamps value to the min…max range
- loop(value, min, max) - loops the value along the min…max range (e.g. loop(1.2, 0, 1) = 0.2.
- min(a, b) - returns a or b, whichever is smaller
- max(a, b) - returns a or b, whichever is larger
You can use variables in place of any value in Story Machine. Variables may have spaces in their names, and are not case-sensitive. Note however that variable names must be unique, and spaces/case are not differentiating. Therefore “my Value X” is the same variable name as “myvaluex”.