mirror of
git://projects.qi-hardware.com/openwrt-packages.git
synced 2024-08-26 23:54:38 +03:00
257 lines
6.2 KiB
Lua
257 lines
6.2 KiB
Lua
--[[ $Id: x21.lua 9533 2009-02-16 22:18:37Z smekal $
|
|
Grid data demo
|
|
|
|
Copyright (C) 200 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")
|
|
|
|
-- bitwise or operator from http://lua-users.org/wiki/BaseSixtyFour
|
|
-- (c) 2006-2008 by Alex Kloss
|
|
-- licensed under the terms of the LGPL2
|
|
|
|
-- return single bit (for OR)
|
|
function bit(x,b)
|
|
return (math.mod(x, 2^b) - math.mod(x,2^(b-1)) > 0)
|
|
end
|
|
|
|
-- logic OR for number values
|
|
function lor(x,y)
|
|
result = 0
|
|
for p=1,8 do result = result + (((bit(x,p) or bit(y,p)) == true) and 2^(p-1) or 0) end
|
|
return result
|
|
end
|
|
|
|
-- Options data structure definition.
|
|
pts = 500
|
|
xp = 25
|
|
yp = 20
|
|
nl = 16
|
|
knn_order = 20
|
|
threshold = 1.001
|
|
wmin = -1e3
|
|
randn = 0
|
|
rosen = 0
|
|
|
|
|
|
function cmap1_init()
|
|
i = { 0, 1 } -- left and right boundary
|
|
|
|
h = { 240, 0 } -- blue -> green -> yellow -> red
|
|
l = { 0.6, 0.6 }
|
|
s = { 0.8, 0.8 }
|
|
|
|
pl.scmap1n(256)
|
|
pl.scmap1l(0, i, h, l, s)
|
|
end
|
|
|
|
|
|
function create_grid(px, py)
|
|
local x = {}
|
|
local y = {}
|
|
|
|
for i = 1, px do
|
|
x[i] = xm + (xM-xm)*(i-1)/(px-1)
|
|
end
|
|
|
|
for i = 1, py do
|
|
y[i] = ym + (yM-ym)*(i-1)/(py-1)
|
|
end
|
|
|
|
return x, y
|
|
end
|
|
|
|
|
|
function create_data(pts)
|
|
local x = {}
|
|
local y = {}
|
|
local z = {}
|
|
|
|
for i = 1, pts do
|
|
xt = (xM-xm)*pl.randd()
|
|
yt = (yM-ym)*pl.randd()
|
|
if randn==0 then
|
|
x[i] = xt + xm
|
|
y[i] = yt + ym
|
|
else -- std=1, meaning that many points are outside the plot range
|
|
x[i] = math.sqrt(-2*math.log(xt)) * math.cos(2*math.pi*yt) + xm
|
|
y[i] = math.sqrt(-2*math.log(xt)) * math.sin(2*math.pi*yt) + ym
|
|
end
|
|
if rosen==0 then
|
|
r = math.sqrt(x[i]^2 + y[i]^2)
|
|
z[i] = math.exp(-r^2) * math.cos(2*math.pi*r)
|
|
else
|
|
z[i] = math.log((1-x[i])^2 + 100*(y[i] - x[i]^2)^2)
|
|
end
|
|
end
|
|
|
|
return x, y, z
|
|
end
|
|
|
|
|
|
title = { "Cubic Spline Approximation",
|
|
"Delaunay Linear Interpolation",
|
|
"Natural Neighbors Interpolation",
|
|
"KNN Inv. Distance Weighted",
|
|
"3NN Linear Interpolation",
|
|
"4NN Around Inv. Dist. Weighted" }
|
|
|
|
|
|
|
|
xm = -0.2
|
|
ym = -0.2
|
|
xM = 0.6
|
|
yM = 0.6
|
|
|
|
pl.parseopts(arg, pl.PL_PARSE_FULL)
|
|
|
|
opt = { 0, 0, wmin, knn_order, threshold, 0 }
|
|
|
|
-- Initialize plplot
|
|
pl.init()
|
|
|
|
-- Initialise random number generator
|
|
pl.seed(5489)
|
|
|
|
x, y, z = create_data(pts) -- the sampled data
|
|
zmin = z[1]
|
|
zmax = z[1]
|
|
for i=2, pts do
|
|
if z[i]>zmax then zmax = z[i] end
|
|
if z[i]<zmin then zmin = z[i] end
|
|
end
|
|
|
|
xg, yg = create_grid(xp, yp) -- grid the data at
|
|
clev = {}
|
|
|
|
pl.col0(1)
|
|
pl.env(xm, xM, ym, yM, 2, 0)
|
|
pl.col0(15)
|
|
pl.lab("X", "Y", "The original data sampling")
|
|
pl.col0(2)
|
|
pl.poin(x, y, 5)
|
|
pl.adv(0)
|
|
|
|
pl.ssub(3, 2)
|
|
|
|
for k = 1, 2 do
|
|
pl.adv(0)
|
|
for alg=1, 6 do
|
|
zg = pl.griddata(x, y, z, xg, yg, alg, opt[alg])
|
|
|
|
--[[
|
|
- CSA can generate NaNs (only interpolates?!).
|
|
- DTLI and NNI can generate NaNs for points outside the convex hull
|
|
of the data points.
|
|
- NNLI can generate NaNs if a sufficiently thick triangle is not found
|
|
|
|
PLplot should be NaN/Inf aware, but changing it now is quite a job...
|
|
so, instead of not plotting the NaN regions, a weighted average over
|
|
the neighbors is done. --]]
|
|
|
|
|
|
if alg==pl.GRID_CSA or alg==pl.GRID_DTLI or alg==pl.GRID_NNLI or alg==pl.GRID_NNI then
|
|
for i = 1, xp do
|
|
for j = 1, yp do
|
|
if zg[i][j]~=zg[i][j] then -- average (IDW) over the 8 neighbors
|
|
zg[i][j] = 0
|
|
dist = 0
|
|
|
|
for ii=i-1, i+1 do
|
|
if ii<=xp then
|
|
for jj=j-1, j+1 do
|
|
if jj<=yp then
|
|
if ii>=1 and jj>=1 and zg[ii][jj]==zg[ii][jj] then
|
|
if (math.abs(ii-i) + math.abs(jj-j)) == 1 then
|
|
d = 1
|
|
else
|
|
d = 1.4142
|
|
end
|
|
zg[i][j] = zg[i][j] + zg[ii][jj]/(d^2)
|
|
dist = dist + d
|
|
end
|
|
end
|
|
end
|
|
end
|
|
end
|
|
if dist~=0 then
|
|
zg[i][j] = zg[i][j]/dist
|
|
else
|
|
zg[i][j] = zmin
|
|
end
|
|
end
|
|
end
|
|
end
|
|
end
|
|
|
|
lzM, lzm = pl.MinMax2dGrid(zg)
|
|
|
|
if lzm~=lzm then lzm=zmin else lzm = math.min(lzm, zmin) end
|
|
if lzM~=lzM then lzM=zmax else lzM = math.max(lzM, zmax) end
|
|
|
|
-- Increase limits slightly to prevent spurious contours
|
|
-- due to rounding errors
|
|
lzm = lzm-0.01
|
|
lzM = lzM+0.01
|
|
|
|
pl.col0(1)
|
|
|
|
pl.adv(alg)
|
|
|
|
if k==1 then
|
|
for i = 1, nl do
|
|
clev[i] = lzm + (lzM-lzm)/(nl-1)*(i-1)
|
|
end
|
|
|
|
pl.env0(xm, xM, ym, yM, 2, 0)
|
|
pl.col0(15)
|
|
pl.lab("X", "Y", title[alg])
|
|
pl.shades(zg, xm, xM, ym, yM, clev, 1, 0, 1, 1)
|
|
pl.col0(2)
|
|
else
|
|
for i = 1, nl do
|
|
clev[i] = lzm + (lzM-lzm)/(nl-1)*(i-1)
|
|
end
|
|
|
|
cmap1_init()
|
|
pl.vpor(0, 1, 0, 0.9)
|
|
pl.wind(-1.1, 0.75, -0.65, 1.20)
|
|
|
|
-- For the comparison to be fair, all plots should have the
|
|
-- same z values, but to get the max/min of the data generated
|
|
-- by all algorithms would imply two passes. Keep it simple.
|
|
--
|
|
-- pl.w3d(1, 1, 1, xm, xM, ym, yM, zmin, zmax, 30, -60)
|
|
|
|
|
|
pl.w3d(1, 1, 1, xm, xM, ym, yM, lzm, lzM, 30, -40)
|
|
pl.box3("bntu", "X", 0, 0,
|
|
"bntu", "Y", 0, 0,
|
|
"bcdfntu", "Z", 0.5, 0)
|
|
pl.col0(15)
|
|
pl.lab("", "", title[alg])
|
|
pl.plot3dc(xg, yg, zg, lor(lor(pl.DRAW_LINEXY, pl.MAG_COLOR), pl.BASE_CONT), clev)
|
|
end
|
|
end
|
|
end
|
|
|
|
pl.plend()
|