Thank you so much for the reply. It worked for me now.

Can you please tell me how to find errors in mathematica. Sometime I do not get any error but at the same time not the required output.

For example I was trying the code:

ClearAll["Global`*"]

Needs["FastPicard`"]

ftmmathieu = FloquetMatrix[{{0, 1}, {-a - b Cos[#1], 0}} &, 20];

Timing[pend1 = With[{matrix = ftmmathieu /. {a -> -3/2 v^2, b -> 3 h/2}}, ContourPlot[Tr[matrix], {h, 0, 0.5}, {v, 0.1, 100}, Contours -> {-2, 2}, ContourShading -> False, PlotPoints -> 120, FrameLabel -> {StyleForm["\!\(\[Epsilon]/l\)", "TR", FontSize -> 10], StyleForm["\!\(w\_0\)\!\(\@\(l/g\)\)", "TR", FontSize -> 10]}]];]

The expected output is a contour plot with the time {118.15 Seconds,Null}.

The output I am getting is {4.042254, Null}.

Thanks for the help.