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Re: [mg4441] a question on ContourPlot
Posted:
Jul 30, 1996 2:59 AM


"David E. Burmaster" <deb@alceon.com> Subject: [mg4441] a question on ContourPlot writes > I have made a complicated contour plot (on linear axes) that I > would like to convert to semilog axes.... > This does NOT work: > Show[ plot/.{a_, b_} > {a, Log[b]}] > That command converts the yaxis but does not transform the > contours..... > Could anyone pls suggest another approach?
David,
With cp = ContourPlot[x^2 y^2, {x,.001,2}, {y,.001,2.72}] cp contains only a matrix of heights from which the polygons and lines are constructed. It also has the option MeshRange > {{0.001, 2.}, {0.001, 2.72}}. The only effect of cp/{a_, b_} > {a, Log[b]} on cp is to change this option to MeshRange > {{0.001, 2.}, {6.90776, 1.00063}} which, in the display, merely changes the yaxis ticks, as you found.
However if you generate the contour lines and polygons (used for shading) explicitely gcp = Graphics[cp] Then lgcp = gcp/{a_?NumberQ, b_} > {a, Log[b]} will alter these elements as you want. Show[lgcp] (You can see the internal form of cp... by using InputForm[cp] ...) Allan Hayes hay@haystack.demon.co.uk



