# Description:
# Display an XY plot of snow depth vs. time with temperature as color-coded
# Z component
Time = seq(6)
# Snow depth at each time point
y = {35,37,46,65,90,92}
# Outdoor temperature at each time point
z = {22,24,27,29,33,36}
# The XY line will be drawn as blue when the temperature is less than 25 degrees,
# yellow when the temperature is between 25 and 32 degrees, and red when
# the temperature is greater than 32 degrees.
colors = {"blue", "yellow", "red"}
levels = {25., 32.}
glevel(levels)
gcolor(colors)
gplot(Time, y, z, "solid", "levels")
gxtitle("Time")
gytitle("Snow Depth")
gtitle(" Blue < 25 degrees; Red > 32 degrees")