parameter

parameterNodeAliases:param

A named quantity the reader can vary with a slider. Inside a canvas.graph it drives every expression that mentions its letter — a curve of a * x^2 bends as a moves. name: is what the slider is called in front of the reader — rich text, so Frequency $b$ sets its own maths — and without one it is labelled with its letter. The current value is derived: prose cites it with {{#a.value}}.

Writing with it:Parameters & cues

#Attributes

varRequiredImplicit
Variable name (single letter, a-z).Can be written as shorthand: parameter:value
Also written: labelWhat the parameter is called in front of a reader. Rich text, so Frequency bb sets its own maths.
Range interval [start, end].
Default[-10, 10]
step
Step size.
Default1
default
Default value.
Default0
hiddenAnimatable
Keeps the parameter out of the footer: the expressions still use it, the reader cannot move it.
Defaultfalse
Also written: lockedKeeps the reader from editing it on an editable: graph.
Defaultfalse

#Derived attributes

Computed while the element renders — read one with #id.name in attribute position or {{#id.name}} in prose, never set.

valueDerived
The value the reader has currently set (the default until touched).

#Allowed in

#Examples

parameter#a(var: a; name: steepness; range: [0, 4]; step: 0.25; default: 2)
curve(f: a * x^2; domain: [-3, 3])
parameter(
    var: a
    name: Frequency $a$
    range: [-5, 5]
    step: 0.5
)