valueNumber method
Sets a channel to a constant number rather than to a column.
channel The channel name.
value The constant.
Returns This mark, so calls chain.
See also valueString.
Implementation
VlChartMark valueNumber(String channel, double value) {
VlJson ch = VlJson.objectValue();
ch.setMember("value", VlJson.numberValue(value));
this.enc.setMember(channel, ch);
cursor = channel;
return this;
}