Parameter

parameterBlock elementGraphAliases: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. The body is what the parameter is called in front of a reader; without one it shows as its letter.

Attributes

varRequiredImplicit

single-char

Variable name (single letter, a-z).The head shorthand supplies it: parameter:value

name

Also written: labelWhat the parameter is called in front of a reader. Rich text, so Frequency $b$ sets its own maths.

range

parametised-interval

Range interval [start, end].

Default[-10, 10]

step

number

Step size.

Default1

default

number

Default value.

Default0

hidden

boolean

Keeps the parameter out of the footer: the expressions still use it, the reader cannot move it.

Defaultfalse

lock

boolean

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 !value:#id.name() in prose, never set.

valueDerived

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

Allowed content

Body { }Inline instructional text and expressions

Allowed in

scene [ ]cue { }cue.draw { }cue.trace { }cue.highlight { }cue.spotlight { }

Examples

parameter{steepness}(var: a; range: [0, 4]; step: 0.25; default: 2)
curve(f: a * x^2; domain: [-3, 3])

parameter{
    Move the slider to change a.
}(
    var: a
    range: [-5, 5]
    step: 0.5
)

Parameter

parameterBlock elementGraphAliases:param

Attributes

varRequiredImplicit

single-char

Variable name (single letter, a-z).The head shorthand supplies it: parameter:value

name

Also written: labelWhat the parameter is called in front of a reader. Rich text, so Frequency $b$ sets its own maths.

range

parametised-interval

Range interval [start, end].

Default[-10, 10]

step

number

Step size.

Default1

default

number

Default value.

Default0

hidden

boolean

Keeps the parameter out of the footer: the expressions still use it, the reader cannot move it.

Defaultfalse

lock

boolean

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 !value:#id.name() in prose, never set.

valueDerived

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

Allowed content

Body { }Inline instructional text and expressions

Allowed in

scene [ ]cue { }cue.draw { }cue.trace { }cue.highlight { }cue.spotlight { }

Examples

parameter{steepness}(var: a; range: [0, 4]; step: 0.25; default: 2)
curve(f: a * x^2; domain: [-3, 3])

parameter{
    Move the slider to change a.
}(
    var: a
    range: [-5, 5]
    step: 0.5
)