Using functions in channel encodings

[marr]

Is there a way to use functions like so when defining channel?

vg.dot(vg.from('stocks'), {
  x: (d) => (d.Close - d.Open) / d.Open,
  y: 'Volume',
  r: 'Volume'
}),

My plot does not appear because in the select statement I see in the log, it is only pulling the Volume column.

[jheer]

Mosaic pushes computation to the database, so instead of a JS function you should be able to provide a SQL expression.

vg.dot(vg.from('stocks'), {
  x: vg.sql`(Close - Open) / Open`,
  y: 'Volume',
  r: 'Volume'
}),

Depending on the column types you may also want to include type casts where needed.

[marr]

That's great. Thank you Jeffrey!