Filtering

Basic manipulations of Ratioscores can be embedded as filtering commands within the score. Filters are given on lines starting with !!!filter: and then the actual filter.

Manipulating spines

The extract filter can be used to pull out specific spines (columns) of data, or rearrange them before converting to MIDI/MP3s. Here is an example where only the first or second voice in the score are selected for performance:

The line !!!filter: extract -s 1,2 keeps the first two spines and removes the third one when converting to MIDI/MP3:

And the line !!!filter: extract -s 1,3 keeps the first and last spines and removes the middle one:

It is possible to include multiple alternate timelines in a score, and then user the extract filter to choose one of them. The following example contains two timelines, with the first one chosen by default:

Removing the first spine will cause the second spine to be used as the timeline:

Rearranging measures

The myank filter can be used to mix and match measures. First, here is a short sequence of notes played through once:

And here is the same music with an myank filter line added to repeat measures in the given order and repetition counts.