How to create a symbolic expression

If a parametric curve is needed to describe the style template, create it using symbolic expressions, for example:

local function_x = "sin(t)"
local function_y = "cos(t)"
CreateParametricCurve2D(function_x, function_y, CoordinateSystem2D.Cartesian, 0, 2 * math.pi)

You can use basic mathematical operations, functions and constants to create a symbolic expression in Renga STDL.

Operations that can be performed on variables, constants, and functions in symbolic expressions:

Operation	Description
+	addition
-	subtraction
*	multiplication
/	division
^	exponentiation
-	unary minus

Mathematical functions that can be used in symbolic expressions:

Function Name	Description
sin	sine with argument in radians
cos	cosine with argument in radians
tan	tangent with argument in radians
sind	sine with argument in degrees
cosd	cosine with argument in degrees
tand	tangent with argument in degrees
asin	arcsine with the result in radians
acos	arccosine with the result in radians
atan	arctangent with the result in radians
asind	arcsine with the result in degrees
acosd	arccosine with the result in degrees
atand	arctangent with the result in degrees
sqrt	square root
exp	exponential
ln	natural logarithm
lg	decimal logarithm
deg	function to convert radians to degrees
rad	function to convert degrees to radians
abs	absolute value

In symbolic expressions, numbers can be represented as unnamed constants, specified as floating-point numbers (a sequence of digits separated by a dot), or as integers.

Symbolic expressions can also include the use of named constants:

Constant Name	Description
M_PI	π - the ratio of a circle's circumference to its diameter
M_PI_2	π / 2
M_PI_4	π / 4
M_SQRT2	√2
M_E	e – the base of the natural logarithm
M_PHI	φ – the golden ratio
M_RADDEG	180 / π – conversion factor from radians to degrees
M_DEGRAD	π / 180 – conversion factor from degrees to radians

When creating symbolic expressions, the following limitations should be taken into account:

• Maximum variable length – 512 characters.
• Maximum expression length – 2048 characters.
• Integrate, differentiate, and limit operations are not supported.
• Simplifying mathematical expressions, such as reducing fractions, is not supported.

Because of these limitations, correct calculations for analytical expressions can only be performed for relatively simple mathematical expressions and functions. For example, calculating the value of sin(t)/t at zero can be inaccurate.