openwrt-packages/nanonote-example-files/files/Examples/lua-plplot-examples/x01.lua

--[[ $Id: x01.lua 9414 2009-01-29 22:48:54Z airwin $

	Simple line plot and multiple windows 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")

-- Variables and data arrays used by plot generators 
x = {}
y = {}
xs = {}
ys = {}

fontset = 1
f_name = ""


function plot1(do_test)
  for i = 1, 60 do
    x[i] = xoff + xscale * (i) / 60
    y[i] = yoff + yscale * x[i]^2
  end

  xmin = x[1]
  xmax = x[60]
  ymin = y[1]
  ymax = y[60]

  for i = 1, 6 do
    xs[i] = x[(i-1) * 10 + 4]
    ys[i] = y[(i-1) * 10 + 4]
  end

  -- Set up the viewport and window using PLENV. The range in X is
  -- 0.0 to 6.0, and the range in Y is 0.0 to 30.0. The axes are
  -- scaled separately (just = 0), and we just draw a labelled
  -- box (axis = 0).
  pl.col0(1)
  pl.env(xmin, xmax, ymin, ymax, 0, 0)
  pl.col0(2)
  pl.lab("(x)", "(y)", "#frPLplot Example 1 - y=x#u2")

  -- Plot the data points 
  pl.col0(4)
  pl.poin(xs, ys, 9)

  -- Draw the line through the data 
  pl.col0(3)
  pl.line(x, y)
end


function plot2()
  -- Set up the viewport and window using PLENV. The range in X is -2.0 to
  -- 10.0, and the range in Y is -0.4 to 2.0. The axes are scaled separately
  --(just = 0), and we draw a box with axes (axis = 1).
  pl.col0(1)
  pl.env(-2, 10, -0.4, 1.2, 0, 1)
  pl.col0(2)
  pl.lab("(x)", "sin(x)/x", "#frPLplot Example 1 - Sinc Function")

  -- Fill up the arrays 
  for i=1, 100 do
    x[i] = (i - 20) / 6
    y[i] = 1
    if x[i] ~= 0 then y[i] = math.sin(x[i])/x[i] end
  end

  -- Draw the line 
  pl.col0(3)
  pl.wid(2)
  pl.line(x, y)
  pl.wid(1)
end


function plot3()
  space0 = { }
  mark0 = { }
  space1 = { 1500 }
  mark1 = { 1500 }

  -- For the final graph we wish to override the default tick intervals, and
  --so do not use plenv().
  pl.adv(0)

  -- Use standard viewport, and define X range from 0 to 360 degrees, Y range
  --from -1.2 to 1.2.
  pl.vsta()
  pl.wind(0, 360, -1.2, 1.2)

  -- Draw a box with ticks spaced 60 degrees apart in X, and 0.2 in Y. 
  pl.col0(1)
  pl.box("bcnst", 60, 2, "bcnstv", 0.2, 2)

  -- Superimpose a dashed line grid, with 1.5 mm marks and spaces.
  -- plstyl expects a pointer!
  pl.styl(mark1, space1)
  pl.col0(2)
  pl.box("g", 30, 0, "g", 0.2, 0)
  pl.styl(mark0, space0)

  pl.col0(3)
  pl.lab("Angle (degrees)", "sine", "#frPLplot Example 1 - Sine function")

  for i=1, 101 do
    x[i] = 3.6*(i-1)
    y[i] = math.sin(x[i]*math.pi/180)
  end

  pl.col0(4)
  pl.line(x, y)
end


----------------------------------------------------------------------------
-- main
--
-- Generates several simple line plots.  Demonstrates:
--   - subwindow capability
--   - setting up the window, drawing plot, and labelling
--   - changing the color
--   - automatic axis rescaling to exponential notation
--   - placing the axes in the middle of the box
--   - gridded coordinate axes
----------------------------------------------------------------------------

-- plplot initialization 

-- Parse and process command line arguments 
pl.parseopts(arg, pl.PL_PARSE_FULL)

-- Get version number, just for kicks 
ver=pl.gver()
print("PLplot library version: " .. ver)

-- Initialize plplot 
-- Divide page into 2x2 plots 
-- Note: calling plstar replaces separate calls to plssub and plinit 
pl.star(2,2)

-- Select font set as per input flag 
if fontset ~= 0 then
	pl.fontld(1)
else
	pl.fontld(0)
end
  
-- Set up the data 
-- Original case 
xscale = 6
yscale = 1
xoff = 0
yoff = 0

-- Do a plot 
plot1(0)

-- Set up the data 
xscale = 1
yscale = 0.0014
yoff = 0.0185

-- Do a plot 
digmax = 5
pl.syax(digmax, 0)

plot1(1)
plot2()
plot3()

-- Show how to save a plot:
-- Open a new device, make it current, copy parameters,
-- and replay the plot buffer
if f_name~="" then -- command line option '-save filename' 
  print("The current plot was saved in color Postscript under the name " .. f_name .. ".\n")
  cur_strm = pl.gstrm()    -- get current stream 
  new_strm = pl.mkstrm()   -- create a new one 

  pl.sfnam(f_name)       -- file name 
  pl.sdev("psc")         -- device type 

  pl.cpstrm(cur_strm, 0) -- copy old stream parameters to new stream 
  pl.replot()	     -- do the save by replaying the plot buffer 
  pl.plend1()              -- finish the device 

  pl.sstrm(cur_strm)     -- return to previous stream 
end

-- Don't forget to call plend() to finish off! 
pl.plend()