x		y
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set cntrparam levels 20
set title "3D gnuplot demo - contour plot (more contours)"
replot

Click here for minimal script to generate this plot

x		y
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set cntrparam levels incr -100,10,100
set title "3D gnuplot demo - contour plot (every 10, starting at -100)"
replot

Click here for minimal script to generate this plot

x		y
			①	②	③	④	⑤	⑥	⑦

set cntrparam levels disc -75,-50,0
set title "3D gnuplot demo - contour plot (at -75, -50, 0)"
replot

Click here for minimal script to generate this plot

x		y
			①	②	③	④	⑤	⑥	⑦

set cntrparam levels auto 10
set title "3D gnuplot demo - contour plot on base grid"
set contour base
splot x**2-y**2

Click here for minimal script to generate this plot

x		y
			①	②	③	④	⑤	⑥	⑦

set title "3D gnuplot demo - contour plot on surface"
set contour surface
replot

Click here for minimal script to generate this plot

x		y
			①	②	③	④	⑤	⑥	⑦

set title "3D gnuplot demo - contour plot on both"
set contour both
replot

Click here for minimal script to generate this plot

x		y
			①	②	③	④	⑤	⑥	⑦

set contour base
set title "3D gnuplot demo - 2 surfaces"
splot x**2*y**3, x**3*y**2

Click here for minimal script to generate this plot

x		y
			①	②	③	④	⑤	⑥	⑦

set title "3D gnuplot demo - some more interesting contours"
splot x*y / (x**2 + y**2 + 0.1)

Click here for minimal script to generate this plot

x		y
			①	②	③	④	⑤	⑥	⑦

splot [x=-3:3] [y=-3:3] sin(x) * cos(y)

Click here for minimal script to generate this plot

x		y
			①	②	③	④	⑤	⑥	⑦

set zrange [-1.0:1.0]
replot

Click here for minimal script to generate this plot

x		y
			①	②	③	④	⑤	⑥	⑦

set samples 6
set isosamples 6
set cntrparam levels 5
set title "3D gnuplot demo - low resolution (6x6)"
replot

Click here for minimal script to generate this plot

x		y
			①	②	③	④	⑤	⑥	⑦

set cntrparam bspline
set title "3D gnuplot demo - low resolution (6x6) using bspline approx."
replot

Click here for minimal script to generate this plot

x		y
			①	②	③	④	⑤	⑥	⑦

set cntrparam order 8
set title "3D gnuplot demo - low resolution (6x6) raise bspline order."
replot

Click here for minimal script to generate this plot

x		y
			①	②	③	④	⑤	⑥	⑦

set cntrparam linear
set auto
set title "3D gnuplot demo - low resolution (6x6) using linear contours."
splot x*y

Click here for minimal script to generate this plot

x		y
			①	②	③	④	⑤	⑥	⑦

set cntrparam order 4
set cntrparam bspline
set title "3D gnuplot demo - low resolution (6x6) using bspline approx."
replot

Click here for minimal script to generate this plot

x		y
			①	②	③	④	⑤	⑥	⑦

set samples 25
set isosamples 26
set title "3D gnuplot demo - contour of Sinc function"
splot [-5:5.01] [-5:5.01] sin(sqrt(x**2+y**2)) / sqrt(x**2+y**2)

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x		y
			①	②	③	④	⑤	⑥	⑦

splot [-12:12.01] [-12:12.01] sin(sqrt(x**2+y**2)) / sqrt(x**2+y**2)

Click here for minimal script to generate this plot

x		y
			①	②	③	④	⑤	⑥	⑦

set cntrparam levels 10
set auto
set zrange [-1.0:1.0]
set style data lines
set title "3D gnuplot demo - contour of data grid plotting"
set parametric
splot "glass.dat"

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x		y
			①	②	③	④	⑤	⑥	⑦

set xrange [0:15]
set yrange [0:15]
set zrange [-1.2:1.2]
unset parametric
splot "glass.dat" using 1

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x		y
			①	②	③	④	⑤	⑥	⑦

set view map
unset surface
set title "3D gnuplot demo - 2D contour projection of last plot"
replot

Click here for minimal script to generate this plot

x		y
			①	②	③	④	⑤	⑥	⑦

#From: shen@athena.cs.uga.edu (Mingzuo Shen)
#Subject: Rosenbrock's function: some answers and thanks
#Date: Wed, 23 Jun 1993 20:50:36 GMT
#
#    Last night I asked for help with a contour plot for the function:
#
#    (1-x)**2 + 100 * (y - x**2)**2
#
#which should have a minimum at (x=1,y=1). This is the 2D case of a more
#general function named after Rosenbrock (the book I am reading does not
#give a reference to any paper/book by this person):
#
#    for even integer n,
#
#    f(x) = \sum_{j=1,3,5,\ldots,n} [(1 - x_j)^2 + 100(x_{j+1} - x_j^2)^2]
#
#where x is a vector (x1, x2, ..., x_n). This function also have a minimum
#at (1,1,...,1), which lies at the base of a "banana-shaped valley".
#Here are the new commands I have tried.
#
set auto
set surface
unset contour
set cntrparam levels 5
set cntrparam linear
set samples 100
set logscale z
set hidden3d
set isosamples 20
set view 70,335,1,1
set xlabel "x"
set ylabel "y"
set title "Rosenbrock Function"
splot [0.9:1.1] [0.9:1.1] (1-x)**2 + 100*(y - x**2)**2

Click here for minimal script to generate this plot

x		y
			①	②	③	④	⑤	⑥	⑦

set logscale z
set hidden3d
set isosamples 60
set ticslevel 0.
set view 20,340	#HBB: ,1,2
set xlabel "x"
set ylabel "y"
splot [-1.5:1.5] [-0.5:1.5] (1-x)**2 + 100*(y - x**2)**2

Click here for minimal script to generate this plot

x		y
			①	②	③	④	⑤	⑥	⑦

set contour
unset surface
unset ztics
unset zlabel
set border 15
replot

Click here for minimal script to generate this plot

x		y
			①	②	③	④	⑤	⑥	⑦

#
set title "All contours drawn in a single color"
unset clabel
splot [-1.5:1.5] [-0.5:1.5] (1-x)**2 + 100*(y - x**2)**2 with lines lc rgb "#007700"

Click here for minimal script to generate this plot

x		y
			①	②	③	④	⑤	⑥	⑦

#
# Clean up:
#