Package 'pipopaplot'

Convert data to a standardized notes tibble

Description

as_notes() converts an arbitrary data frame or a ggplot object into a tibble containing the required columns for MIDI sonification: x, y, channel, group, duration, and velocity.

Usage

as_notes(d, ...)

## Default S3 method:
as_notes(d, ...)

## S3 method for class 'ggplot'
as_notes(d, ..., .id = 1)

Arguments

d	A data frame or a ggplot2 object. When a ggplot2 object is given, the layer data is extracted using ggplot2::get_layer_data() with the layer index specified by .id.
...	Optional name mappings. Provide named arguments to override the default column names (e.g., as_notes(d, duration = "fill") will use fill as the duration column).
.id	Layer index to extract from a ggplot object. Defaults to 1.

Details

The returned tibble serves as the standard 'notes' format accepted by sonify(). Numeric or logical columns are converted to numeric and missing values are replaced with 1.

Value

A tibble with columns:

• x, y – coordinate-like values to be mapped to time and pitch

• channel – grouping for MIDI channels

• group – sub-group within each channel

• duration, velocity – numeric modifiers for note length and intensity

---

Aggregate or transform note data before sonification

Description

rollup() provides a simple mechanism to summarize or reshape note-level data prior to sonification. By default, it performs numeric aggregation within each ⁠(channel, group, by)⁠ combination.

Usage

rollup(d, by, .fun = base::mean)

Arguments

d	A data frame returned by as_notes().
by	A variable or expression used for grouping within each ⁠(channel, group)⁠ pair.
.fun	A summary function applied to numeric columns. Defaults to base::mean().

Details

Although rollup() uses summarization by default, any transformation that returns a data frame with the expected columns will work in a sonification pipeline. Users can define their own custom rollup functions, including those that duplicate rows to generate chords or parallel voices.

Value

A data frame containing the same key columns (x, y, channel, group, duration, velocity) and suitable for use in sonify().

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Map note data to MIDI event timings and values

Description

sonify() transforms a notes tibble into a structured data frame of note-on and note-off events that can be written to a Standard MIDI file via write_midi().

Usage

sonify(
  notes,
  phrase_len = 4,
  tpq = 480,
  pitch_range = c(27, 102),
  vel_range = c(60, 100),
  duration_range = c(16, 4),
  offset = 0.1
)

Arguments

notes	A tibble containing columns x, y, channel, group, duration, and velocity. channel and group should be factors; other columns should be numeric.
phrase_len	Length of the phrase in beats.
tpq	Ticks per quarter note.
pitch_range	Range of MIDI note numbers to map y onto.
vel_range	Range of MIDI velocities to map velocity onto.
duration_range	Range of note durations (in ticks) mapped from duration. Default c(16, 4) (shorter to longer).
offset	Padding fraction for mapping x values.

Details

Value scaling is handled by scales::rescale(), so the input value ranges are arbitrary but must be finite. Note that because of this rescaling behavior, a velocity value of 0 will not be mapped to complete silence by default (i.e., the minimum input value will still be mapped to the lower bound of vel_range rather than 0).

Within each channel, duplicated timing values (x) are deduplicated using dplyr::distinct(). To produce simultaneous notes (like chords), you must assign different channel values in advance.

Value

A data frame with factor and integer columns: channel, group, tick_on, tick_off, pitch, and velocity. Suitable as input to write_midi().

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Write a data frame of notes to a Standard MIDI file

Description

Write a data frame of notes to a Standard MIDI file

Usage

write_midi(notes, filename = "test.mid", opt = list())

Arguments

notes	A data frame containing columns tick_on, tick_off, pitch, and velocity. tick_on and tick_off should be integers. pitch and velocity should be integers. channel and group should be factors; other columns should be numeric.
filename	Name of the output file.
opt	A list of options.

Value

The path to the output file is invisibly returned.

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