mirror of https://github.com/swig/swig
67 lines
1.3 KiB
Ruby
67 lines
1.3 KiB
Ruby
# Plot a 3D function
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require 'gifplot'
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include Math
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# Here is the function to plot
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def func(x,y)
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return 5*cos(2*sqrt(x*x+y*y))*exp(-0.3*sqrt(x*x+y*y))
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end
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# Here are some plotting parameters
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XMIN = -5.0
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XMAX = 5.0
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YMIN = -5.0
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YMAX = 5.0
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ZMIN = -5.0
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ZMAX = 5.0
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# Grid resolution
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NXPOINTS = 60
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NYPOINTS = 60
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cmap = Gifplot::ColorMap.new("cmap")
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frame = Gifplot::FrameBuffer.new(500,500)
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frame.clear(Gifplot::BLACK)
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P3 = Gifplot::Plot3D.new(frame,XMIN,YMIN,ZMIN,XMAX,YMAX,ZMAX)
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P3.lookat(2*[XMAX-XMIN,YMAX-YMIN,ZMAX-ZMIN].max)
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P3.autoperspective(40)
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P3.rotu(60)
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P3.rotr(30)
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P3.rotd(10)
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def drawsolid()
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P3.clear(Gifplot::BLACK)
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P3.start()
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dx = 1.0*(XMAX-XMIN)/NXPOINTS
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dy = 1.0*(YMAX-YMIN)/NYPOINTS
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cscale = 240.0/(ZMAX-ZMIN)
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x = XMIN
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for i in 0...NXPOINTS
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y = YMIN
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for j in 0...NYPOINTS
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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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c = (c1+c2+c3+c4)/4
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c = 0 if (c < 0)
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c = 239 if c > 239
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P3.solidquad(x,y,z1,x+dx,y,z2,x+dx,y+dy,z3,x,y+dy,z4,c+16)
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y = y + dy
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end
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x = x + dx
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end
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end
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puts "Making a nice 3D plot..."
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drawsolid()
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frame.writeGIF(cmap,"image.gif")
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puts "Wrote image.gif"
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