ch.WriteKey – output key at given location

By default, Rain completes the key when you end the chart with ch.Close, so you normally do not need this function. You would use it:

• to position the key at an exact x,y location:
  ch.WriteKey 10 10
• to flush out the key after each plot in a multiple set:
  ch.WriteKey Ð

Note that before you do any plotting, the entire chart region has notional axes of 0–100 in both directions, so that you can use ch.New and ch.Nul to position a key anywhere in the plotting space. See the Intercepts example for the technique.