# How to Fill ContourPlot

Given a contour plot such as

function = Cos[c] + Cos[a]
pltc = ContourPlot[function == 1/2, {a, 0, 4 Pi}, {c, 0, 4 Pi}];


How can I color the regions in which function > 1/2 one color and function < 1/2 another color?

• Possible duplicate: (47897) Apr 14 '15 at 0:39

ContourPlot[Cos[c] + Cos[a], {a, 0, 4 Pi}, {c, 0, 4 Pi},

you can also use RegionPlot
RegionPlot[{function <= 1/2, function > 1/2}, {a, 0, 4 Pi}, {c, 0,