Help - User Expressions

From TTA Help System

In Topological Tree Analyszer user-defined expressions are used to calculate the actual data (e.g., distances between trees) from basic topological values. A set of functions is available to formulate such expressions and to access the basic values. An unlimited number of user expressions can be defined and will be written to a results table at the end of an analysis. It is also possible to reference results from one user expression from another one and reuse the result there.

Functions to access basic topological values

Functions to access results of other expressions

Operators

The following list contains all valid operators. Each operator binds as strong or more than all operators listed below. The right columns indicate which types the operands need to have.

Name: Operator: Numeric: Textual: Boolean: Example:
Power ^ YesSymbol.png NoSymbol.png NoSymbol.png 10^-2 (= 0.02)
Unary plus + YesSymbol.png NoSymbol.png NoSymbol.png +4
Unary minus - YesSymbol.png NoSymbol.png NoSymbol.png -4
Modulo % YesSymbol.png NoSymbol.png NoSymbol.png 10 % 4 (= 2)
Division / YesSymbol.png NoSymbol.png NoSymbol.png treeUserValue("someValue") / 2
Multiplication * YesSymbol.png NoSymbol.png NoSymbol.png treeUserValue("someValue") * 100
Addition + YesSymbol.png YesSymbol.png NoSymbol.png
treeUserValue("someValue") + 10
"Two " + "words"
Less or equal <= YesSymbol.png NoSymbol.png NoSymbol.png if(treeUserValue("someValue") <= 100, treeUserValue("someValue"), 100)
Greater or equal >= YesSymbol.png NoSymbol.png NoSymbol.png if(treeUserValue("someValue") <= 100, "A", "B")
Less then < YesSymbol.png NoSymbol.png NoSymbol.png if(treeUserValue("someValue") < 100, treeUserValue("someValue"), 100)
Greater then > YesSymbol.png NoSymbol.png NoSymbol.png if(treeUserValue("someValue") < 100, "A", "B")
Equal = YesSymbol.png YesSymbol.png NoSymbol.png if(treeUserValue("value1") = 100, treeUserValue("value2"), treeUserValue("value3"))
Not equal != YesSymbol.png YesSymbol.png NoSymbol.png if(treeUserValue("value1") != "empty", treeUserValue("value2"), 0)
And && NoSymbol.png NoSymbol.png YesSymbol.png if(treeUserValue("value1") < 100 && treeUserValue("value1") > 50, treeUserValue("value2"), "")
Or || NoSymbol.png NoSymbol.png YesSymbol.png if(treeUserValue("value1") < 100 || treeUserValue("value2") < 100, treeUserValue("value3"), "undefined")

Text functions

General mathematical functions

Name: Definition: Description:
Sine sin(Numeric x) Calculates the sine of the passed numeric value.
Cosine cos(Numeric x) Calculates the cosine of the passed numeric value.
Tangent tan(Numeric x) Calculates the tangent of the passed numeric value.
Inverse sine asin(Numeric x) Calculates the inverse sine of the passed numeric value.
Inverse cosine acos(Numeric x) Calculates the inverse cosine of the passed numeric value.
Inverse tangent atan(Numeric x) Calculates the inverse tangent of the passed numeric value.
Inverse tangent atan2(Numeric x, Numeric y) Calculates the inverse tangent (or arcus tangent) of y / x given adjacent and x. The result is between -π and π
Hyperbolic sine sinh(Numeric x) Calculates the hyperbolic sine of the given angle.
Hyperbolic cosine cosh(Numeric x) Calculates the hyperbolic cosine of the given angle.
Hyperbolic tangent tanh(Numeric x) Calculates the hyperbolic tangent of the given angle.
Inverse hyperbolic sine asinh(Numeric x) Calculates the inverse hyperbolic sine of the given angle.
Inverse hyperbolic cosine acosh(Numeric x) Calculates the inverse hyperbolic cosine of the given angle.
Inverse hyperbolic tangent atanh(Numeric x) Calculates the inverse hyperbolic tangent of the given angle.
Natural logarithm ln(Numeric x) Calculates the natural logarithm of the passed numeric value.
Logarithm to the base 10 log(Numeric x) Calculates the logarithm to the base 10 of the passed numeric value.
Exponential function exp(Numeric x) Calculates the exponential function to the base e. It is the inverse function of the natural logarithm (ln).
Magnitude abs(Numeric x) Returns the absolute value of the passed numeric parameter.
Random number rand(Numeric x) Returns a random number between 0 and 1.
Square Root sqrt(Numeric x) Calculates the square root of the passed numeric parameter.
Alternative if(Boolean condition, Numeric or textual trueValue, Numeric or textual falseValue) Returns the second parameter if the condition is true or the third if not.
Number to text str(Numeric or textual x) Returns a textual representation of the passed parameter.

General constants