27705dc6ff
git-svn-id: https://swig.svn.sourceforge.net/svnroot/swig/trunk/SWIG@815 626c5289-ae23-0410-ae9c-e8d60b6d4f22
66 lines
1.6 KiB
Scheme
66 lines
1.6 KiB
Scheme
;;; Plot a 3D function
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;; Use the wrapped GIFPlot library
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(use-modules (gifplot))
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;; Here is the function to plot
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(define (func x y)
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(* 5
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(cos (* 2 (sqrt (+ (* x x) (* y y)))))
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(exp (* -0.3 (sqrt (+ (* x x) (* y y)))))))
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;; Here are some plotting parameters
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(define xmin -5.0)
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(define xmax 5.0)
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(define ymin -5.0)
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(define ymax 5.0)
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(define zmin -5.0)
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(define zmax 5.0)
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;; Grid resolution
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(define nxpoints 60)
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(define nypoints 60)
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(define cmap (new-ColorMap "cmap"))
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(define frame (new-FrameBuffer 500 500))
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(FrameBuffer-clear frame (BLACK))
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(define p3 (new-Plot3D frame xmin ymin zmin xmax ymax zmax))
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(Plot3D-lookat p3 (* 2 (- zmax zmin)))
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(Plot3D-autoperspective p3 40)
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(Plot3D-rotu p3 60)
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(Plot3D-rotr p3 30)
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(Plot3D-rotd p3 10)
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(define (drawsolid)
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(Plot3D-clear p3 (BLACK))
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(Plot3D-start p3)
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(let ((dx (/ (- xmax xmin) nxpoints))
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(dy (/ (- ymax ymin) nypoints))
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(cscale (/ 240 (- zmax zmin))))
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(let x-loop ((x xmin) (i 0))
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(cond
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((< i nxpoints)
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(let y-loop ((y ymin) (j 0))
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(cond
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((< j nypoints)
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(let* ((z1 (func x y))
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(z2 (func (+ x dx) y))
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(z3 (func (+ x dx) (+ y dy)))
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(z4 (func x (+ y dy)))
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(c1 (* cscale (- z1 zmin)))
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(c2 (* cscale (- z2 zmin)))
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(c3 (* cscale (- z3 zmin)))
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(c4 (* cscale (- z4 zmin)))
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(cc (/ (+ c1 c2 c3 c4) 4))
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(c (round (max (min cc 239) 0))))
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(Plot3D-solidquad p3 x y z1 (+ x dx) y z2 (+ x dx) (+ y dy)
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z3 x (+ y dy) z4 (+ c 16)))
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(y-loop (+ y dy) (+ j 1)))))
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(x-loop (+ x dx) (+ i 1)))))))
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(display "Making a nice 3D plot...\n")
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(drawsolid)
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(FrameBuffer-writeGIF frame cmap "image.gif")
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(display "Wrote image.gif\n")
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