mirror of
git://projects.qi-hardware.com/openwrt-packages.git
synced 2024-11-22 13:29:21 +02:00
351 lines
8.0 KiB
Lua
351 lines
8.0 KiB
Lua
--[[ $Id: x09.lua 9533 2009-02-16 22:18:37Z smekal $
|
|
|
|
Contour plot demo.
|
|
|
|
Copyright (C) 2008 Werner Smekal
|
|
|
|
This file is part of PLplot.
|
|
|
|
PLplot is free software you can redistribute it and/or modify
|
|
it under the terms of the GNU General Library Public License as published
|
|
by the Free Software Foundation either version 2 of the License, or
|
|
(at your option) any later version.
|
|
|
|
PLplot is distributed in the hope that it will be useful,
|
|
but WITHOUT ANY WARRANTY without even the implied warranty of
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
GNU Library General Public License for more details.
|
|
|
|
You should have received a copy of the GNU Library General Public License
|
|
along with PLplot if not, write to the Free Software
|
|
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
|
|
--]]
|
|
|
|
-- initialise Lua bindings for PLplot examples.
|
|
dofile("plplot_examples.lua")
|
|
|
|
XPTS = 35 -- Data points in x
|
|
YPTS = 46 -- Data points in y
|
|
|
|
XSPA = 2/(XPTS-1)
|
|
YSPA = 2/(YPTS-1)
|
|
|
|
-- polar plot data
|
|
PERIMETERPTS = 100
|
|
RPTS = 40
|
|
THETAPTS = 40
|
|
|
|
-- potential plot data
|
|
PPERIMETERPTS = 100
|
|
PRPTS = 40
|
|
PTHETAPTS = 64
|
|
PNLEVEL = 20
|
|
|
|
clevel = { -1, -0.8, -0.6, -0.4, -0.2, 0, 0.2, 0.4, 0.6, 0.8, 1}
|
|
|
|
-- Transformation function
|
|
tr = { XSPA, 0, -1, 0, YSPA, -1 }
|
|
|
|
function mypltr(x, y)
|
|
tx = tr[1] * x + tr[2] * y + tr[3]
|
|
ty = tr[4] * x + tr[5] * y + tr[6]
|
|
|
|
return tx, ty
|
|
end
|
|
|
|
--polar contour plot example.
|
|
function polar()
|
|
px = {}
|
|
py = {}
|
|
lev = {}
|
|
|
|
pl.env(-1, 1, -1, 1, 0, -2)
|
|
pl.col0(1)
|
|
|
|
--Perimeter
|
|
for i=1, PERIMETERPTS do
|
|
t = (2*math.pi/(PERIMETERPTS-1))*(i-1)
|
|
px[i] = math.cos(t)
|
|
py[i] = math.sin(t)
|
|
end
|
|
pl.line(px, py)
|
|
|
|
--create data to be contoured.
|
|
cgrid2["xg"] = {}
|
|
cgrid2["yg"] = {}
|
|
cgrid2["nx"] = RPTS
|
|
cgrid2["ny"] = THETAPTS
|
|
z = {}
|
|
|
|
for i = 1, RPTS do
|
|
r = (i-1)/(RPTS-1)
|
|
cgrid2["xg"][i] = {}
|
|
cgrid2["yg"][i] = {}
|
|
z[i] = {}
|
|
for j = 1, THETAPTS do
|
|
theta = (2*math.pi/(THETAPTS-1))*(j-1)
|
|
cgrid2["xg"][i][j] = r*math.cos(theta)
|
|
cgrid2["yg"][i][j] = r*math.sin(theta)
|
|
z[i][j] = r
|
|
end
|
|
end
|
|
|
|
for i = 1, 10 do
|
|
lev[i] = 0.05 + 0.10*(i-1)
|
|
end
|
|
|
|
pl.col0(2)
|
|
pl.cont(z, 1, RPTS, 1, THETAPTS, lev, "pltr2", cgrid2)
|
|
pl.col0(1)
|
|
pl.lab("", "", "Polar Contour Plot")
|
|
end
|
|
|
|
|
|
----------------------------------------------------------------------------
|
|
-- f2mnmx
|
|
--
|
|
-- Returns min & max of input 2d array.
|
|
----------------------------------------------------------------------------
|
|
function f2mnmx(f, nx, ny)
|
|
fmax = f[1][1]
|
|
fmin = fmax
|
|
|
|
for i=1, nx do
|
|
for j=1, ny do
|
|
fmax = math.max(fmax, f[i][j])
|
|
fmin = math.min(fmin, f[i][j])
|
|
end
|
|
end
|
|
|
|
return fmin, fmax
|
|
end
|
|
|
|
|
|
--shielded potential contour plot example.
|
|
function potential()
|
|
clevelneg = {}
|
|
clevelpos = {}
|
|
px = {}
|
|
py = {}
|
|
|
|
--create data to be contoured.
|
|
cgrid2["xg"] = {}
|
|
cgrid2["yg"] = {}
|
|
cgrid2["nx"] = PRPTS
|
|
cgrid2["ny"] = PTHETAPTS
|
|
z = {}
|
|
|
|
for i = 1, PRPTS do
|
|
r = 0.5 + (i-1)
|
|
cgrid2["xg"][i] = {}
|
|
cgrid2["yg"][i] = {}
|
|
for j = 1, PTHETAPTS do
|
|
theta = 2*math.pi/(PTHETAPTS-1)*(j-0.5)
|
|
cgrid2["xg"][i][j] = r*math.cos(theta)
|
|
cgrid2["yg"][i][j] = r*math.sin(theta)
|
|
end
|
|
end
|
|
|
|
rmax = PRPTS-0.5
|
|
xmin, xmax = f2mnmx(cgrid2["xg"], PRPTS, PTHETAPTS)
|
|
ymin, ymax = f2mnmx(cgrid2["yg"], PRPTS, PTHETAPTS)
|
|
x0 = (xmin + xmax)/2
|
|
y0 = (ymin + ymax)/2
|
|
|
|
-- Expanded limits
|
|
peps = 0.05
|
|
xpmin = xmin - math.abs(xmin)*peps
|
|
xpmax = xmax + math.abs(xmax)*peps
|
|
ypmin = ymin - math.abs(ymin)*peps
|
|
ypmax = ymax + math.abs(ymax)*peps
|
|
|
|
-- Potential inside a conducting cylinder (or sphere) by method of images.
|
|
-- Charge 1 is placed at (d1, d1), with image charge at (d2, d2).
|
|
-- Charge 2 is placed at (d1, -d1), with image charge at (d2, -d2).
|
|
-- Also put in smoothing term at small distances.
|
|
eps = 2
|
|
q1 = 1
|
|
d1 = rmax/4
|
|
|
|
q1i = - q1*rmax/d1
|
|
d1i = rmax^2/d1
|
|
|
|
q2 = -1
|
|
d2 = rmax/4
|
|
|
|
q2i = - q2*rmax/d2
|
|
d2i = rmax^2/d2
|
|
|
|
for i = 1, PRPTS do
|
|
z[i] = {}
|
|
for j = 1, PTHETAPTS do
|
|
div1 = math.sqrt((cgrid2.xg[i][j]-d1)^2 + (cgrid2.yg[i][j]-d1)^2 + eps^2)
|
|
div1i = math.sqrt((cgrid2.xg[i][j]-d1i)^2 + (cgrid2.yg[i][j]-d1i)^2 + eps^2)
|
|
div2 = math.sqrt((cgrid2.xg[i][j]-d2)^2 + (cgrid2.yg[i][j]+d2)^2 + eps^2)
|
|
div2i = math.sqrt((cgrid2.xg[i][j]-d2i)^2 + (cgrid2.yg[i][j]+d2i)^2 + eps^2)
|
|
z[i][j] = q1/div1 + q1i/div1i + q2/div2 + q2i/div2i
|
|
end
|
|
end
|
|
zmin, zmax = f2mnmx(z, PRPTS, PTHETAPTS)
|
|
|
|
-- Positive and negative contour levels.
|
|
dz = (zmax-zmin)/PNLEVEL
|
|
nlevelneg = 1
|
|
nlevelpos = 1
|
|
for i = 1, PNLEVEL do
|
|
clevel = zmin + (i-0.5)*dz
|
|
if clevel <= 0 then
|
|
clevelneg[nlevelneg] = clevel
|
|
nlevelneg = nlevelneg + 1
|
|
else
|
|
clevelpos[nlevelpos] = clevel
|
|
nlevelpos = nlevelpos + 1
|
|
end
|
|
end
|
|
|
|
-- Colours!
|
|
ncollin = 11
|
|
ncolbox = 1
|
|
ncollab = 2
|
|
|
|
-- Finally start plotting this page!
|
|
pl.adv(0)
|
|
pl.col0(ncolbox)
|
|
|
|
pl.vpas(0.1, 0.9, 0.1, 0.9, 1)
|
|
pl.wind(xpmin, xpmax, ypmin, ypmax)
|
|
pl.box("", 0, 0, "", 0, 0)
|
|
|
|
pl.col0(ncollin)
|
|
if nlevelneg>1 then
|
|
-- Negative contours
|
|
pl.lsty(2)
|
|
pl.cont(z, 1, PRPTS, 1, PTHETAPTS, clevelneg, "pltr2", cgrid2)
|
|
end
|
|
|
|
if nlevelpos>1 then
|
|
-- Positive contours
|
|
pl.lsty(1)
|
|
pl.cont(z, 1, PRPTS, 1, PTHETAPTS, clevelpos, "pltr2", cgrid2)
|
|
end
|
|
|
|
-- Draw outer boundary
|
|
for i = 1, PPERIMETERPTS do
|
|
t = (2*math.pi/(PPERIMETERPTS-1))*(i-1)
|
|
px[i] = x0 + rmax*math.cos(t)
|
|
py[i] = y0 + rmax*math.sin(t)
|
|
end
|
|
|
|
pl.col0(ncolbox)
|
|
pl.line(px, py)
|
|
|
|
pl.col0(ncollab)
|
|
pl.lab("", "", "Shielded potential of charges in a conducting sphere")
|
|
end
|
|
|
|
|
|
----------------------------------------------------------------------------
|
|
-- main
|
|
--
|
|
-- Does several contour plots using different coordinate mappings.
|
|
----------------------------------------------------------------------------
|
|
mark = { 1500 }
|
|
space = { 1500 }
|
|
|
|
-- Parse and process command line arguments
|
|
pl.parseopts(arg, pl.PL_PARSE_FULL)
|
|
|
|
-- Initialize plplot
|
|
pl.init()
|
|
|
|
-- Set up function arrays
|
|
z = {}
|
|
w = {}
|
|
|
|
for i = 1, XPTS do
|
|
xx = (i-1 - math.floor(XPTS/2)) / math.floor(XPTS/2)
|
|
z[i] = {}
|
|
w[i] = {}
|
|
for j = 1, YPTS do
|
|
yy = (j-1 - math.floor(YPTS/2)) / math.floor(YPTS/2) - 1
|
|
z[i][j] = xx^2 - yy^2
|
|
w[i][j] = 2 * xx * yy
|
|
end
|
|
end
|
|
|
|
-- Set up grids
|
|
cgrid1 = {}
|
|
cgrid1["xg"] = {}
|
|
cgrid1["yg"] = {}
|
|
cgrid1["nx"] = XPTS
|
|
cgrid1["ny"] = YPTS
|
|
cgrid2 = {}
|
|
cgrid2["xg"] = {}
|
|
cgrid2["yg"] = {}
|
|
cgrid2["nx"] = XPTS
|
|
cgrid2["ny"] = YPTS
|
|
|
|
for i = 1, XPTS do
|
|
cgrid2["xg"][i] = {}
|
|
cgrid2["yg"][i] = {}
|
|
for j = 1, YPTS do
|
|
xx, yy = mypltr(i-1, j-1)
|
|
|
|
argx = xx * math.pi/2
|
|
argy = yy * math.pi/2
|
|
distort = 0.4
|
|
|
|
cgrid1["xg"][i] = xx + distort * math.cos(argx)
|
|
cgrid1["yg"][j] = yy - distort * math.cos(argy)
|
|
|
|
cgrid2["xg"][i][j] = xx + distort * math.cos(argx) * math.cos(argy)
|
|
cgrid2["yg"][i][j] = yy - distort * math.cos(argx) * math.cos(argy)
|
|
end
|
|
end
|
|
|
|
-- Plot using identity transform
|
|
pl.setcontlabelformat(4, 3)
|
|
pl.setcontlabelparam(0.006, 0.3, 0.1, 1)
|
|
pl.env(-1, 1, -1, 1, 0, 0)
|
|
pl.col0(2)
|
|
pl.cont(z, 1, XPTS, 1, YPTS, clevel, "mypltr")
|
|
pl.styl(mark, space)
|
|
pl.col0(3)
|
|
pl.cont(w, 1, XPTS, 1, YPTS, clevel, "mypltr")
|
|
pl.styl({}, {})
|
|
pl.col0(1)
|
|
pl.lab("X Coordinate", "Y Coordinate", "Streamlines of flow")
|
|
pl.setcontlabelparam(0.006, 0.3, 0.1, 0)
|
|
|
|
-- Plot using 1d coordinate transform
|
|
pl.env(-1, 1, -1, 1, 0, 0)
|
|
pl.col0(2)
|
|
pl.cont(z, 1, XPTS, 1, YPTS, clevel, "pltr1", cgrid1)
|
|
pl.styl(mark, space)
|
|
pl.col0(3)
|
|
pl.cont(w, 1, XPTS, 1, YPTS, clevel, "pltr1", cgrid1)
|
|
pl.styl({}, {})
|
|
pl.col0(1)
|
|
pl.lab("X Coordinate", "Y Coordinate", "Streamlines of flow")
|
|
|
|
-- Plot using 2d coordinate transform
|
|
pl.env(-1, 1, -1, 1, 0, 0)
|
|
pl.col0(2)
|
|
pl.cont(z, 1, XPTS, 1, YPTS, clevel, "pltr2", cgrid2)
|
|
|
|
pl.styl(mark, space)
|
|
pl.col0(3)
|
|
pl.cont(w, 1, XPTS, 1, YPTS, clevel, "pltr2", cgrid2)
|
|
pl.styl({}, {})
|
|
pl.col0(1)
|
|
pl.lab("X Coordinate", "Y Coordinate", "Streamlines of flow")
|
|
|
|
pl.setcontlabelparam(0.006, 0.3, 0.1, 0)
|
|
polar()
|
|
|
|
pl.setcontlabelparam(0.006, 0.3, 0.1, 0)
|
|
potential()
|
|
|
|
-- Clean up
|
|
pl.plend()
|