This is a simple function provided here for the convenience of users. It adds
a key showing how the colors map to the values of an image
plot.
metre(xl, yb, xr, yt, lab, cols = risk.colors(length(lab) - 1), shift = 0,
cex = 1)
Left coordinate of the color level metre bar.
Bottom coordinate of the color level metre bar.
Right coordinate of the color level metre bar.
Top coordinate of the color level metre bar.
metre level labels in the metre.
associated colours, defaults to use risk.colors
.
distance to shift the label texts away from the metre bar.
numeric character expansion factor.