# Plotting Extended Zone Scheme: plot -3pi to 3pi

Plotting Extended Zone Scheme:

ContourPlot[ Cos[k] == Cos[5.12 Sqrt[e]] + 5*Sinc[5.12 Sqrt[e]], {k, 0, π}, {e, 0.1, 1.52}, FrameLabel -> {"k[\!$$\*SuperscriptBox[\(nm$$, $$-1$$]\)]", "Energy[eV]"}, PlotLabel -> Cos[k] == Cos[5.12 Sqrt[e]] + 5*Sinc[5.12 Sqrt[e]]]

i want to know plot this -3pi to 3pi how can i

• The code you've posted does not correspond to the image. Could you tell us which parameter range do you want to alter and where are you stuck? – Kuba May 29 '17 at 12:22
• i want plot k range [-3pi to 3pi] vs e – kim May 29 '17 at 13:00
• who anser k range [0 to 3pi] as ContourPlot[ Cos[k] + I Floor[k/[Pi]] == Cos[5.12 Sqrt[e]] + 5 Sinc[5.12 Sqrt[e]] + I Floor[5.12 Sqrt[e]/[Pi]], {k, 0, 3 [Pi]}, {e, 0, 3.5}, GridLines -> {({#1 [Pi], Dashed} &) /@ Range[3], None}, FrameLabel -> {SequenceForm[k, " [\!(*SuperscriptBox[(nm), (-1)])]"], "Energy [eV]"}, PlotLabel -> Cos[k] == Cos[5.12 Sqrt[e]] + 5 Sinc[5.12 Sqrt[e]]] – kim May 29 '17 at 13:01

Maybe you can use RegionFunction:
ContourPlot[