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C $Id: x03f.fm4,v 1.11 2004/01/17 16:41:39 rlaboiss Exp $
C Generates polar plot with, 1-1 scaling
C
C Copyright (C) 2004 Alan W. Irwin
C
C This file is part of PLplot.
C
C PLplot is free software; you can redistribute it and/or modify
C it under the terms of the GNU General Library Public License as
C published by the Free Software Foundation; either version 2 of the
C License, or (at your option) any later version.
C
C PLplot is distributed in the hope that it will be useful,
C but WITHOUT ANY WARRANTY; without even the implied warranty of
C MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
C GNU Library General Public License for more details.
C
C You should have received a copy of the GNU Library General Public
C License along with PLplot; if not, write to the Free Software
C Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
implicit none
real*8 PI
parameter (PI = 3.1415926535897932384d0)
character*3 text
real*8 x0(0:360), y0(0:360)
real*8 x(0:360), y(0:360), dtr, theta, dx, dy, r
integer i, j, nsp
integer PL_PARSE_FULL
parameter(PL_PARSE_FULL = 1)
C Process command-line arguments
call plparseopts(PL_PARSE_FULL)
dtr = PI/180.0d0
do i=0,360
x0(i) = cos(dtr * dble (i))
y0(i) = sin(dtr * dble (i))
enddo
C Initialize PLplot
call plinit()
C Set up viewport and window, but do not draw box
call plenv(-1.3d0, 1.3d0, -1.3d0, 1.3d0, 1, -2)
do i = 1,10
do j = 0,360
x(j) = 0.1d0*i*x0(j)
y(j) = 0.1d0*i*y0(j)
enddo
C Draw circles for polar grid
call plline(361,x,y)
enddo
call plcol0(2)
do i = 0,11
theta = 30.0d0*i
dx = cos(dtr*theta)
dy = sin(dtr*theta)
C Draw radial spokes for polar grid
call pljoin(0.0d0, 0.0d0, dx, dy)
write (text,'(i3)') nint(theta)
C Write labels for angle
text = text(nsp(text):)
C Slightly off zero to avoid floating point logic flips at
C 90 and 270 deg.
if (dx.ge.-0.00001d0) then
call plptex(dx, dy, dx, dy, -0.15d0, text)
else
call plptex(dx, dy, -dx, -dy, 1.15d0, text)
end if
enddo
C Draw the graph
do i=0,360
r = sin(dtr*dble (5*i))
x(i) = x0(i) * r
y(i) = y0(i) * r
enddo
call plcol0(3)
call plline(361,x,y)
call plcol0(4)
call plmtex('t', 2.0d0, 0.5d0, 0.5d0,
& '#frPLplot Example 3 - r(#gh)=sin 5#gh')
C Close the plot at end
call plend
end
integer function nsp(text)
C ==================
C Find first non-space character
implicit none
character*(*) text
integer l, len
l = len(text)
nsp = 1
do while(text(nsp:nsp).eq.' ' .and. nsp.lt.l)
nsp = nsp+1
enddo
end
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