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c $Id: x03f.fm4 11680 2011-03-27 17:57:51Z airwin $
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 Library General 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
implicit none
include 'plplot_parameters.h'
character*3 text
real*8 x0(0:360), y0(0:360)
real*8 x(0:360), y(0:360), dtr, theta, dx, dy, r, offset
integer i, j, nsp
c Process command-line arguments
call plparseopts(PL_PARSE_FULL)
c Set orientation to portrait - note not all device drivers
c support this, in particular most interactive drivers do not.
call plsori(1)
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)
c Draw circles for polar grid
do i = 1,10
call plarc(0.0d0, 0.0d0, 0.1d0*i, 0.1d0*i,
& 0.0d0, 360.0d0, 0.0d0, 0)
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):)
if (theta .lt. 9.99) then
offset = 0.45
elseif (theta .lt. 99.9) then
offset = 0.30
else
offset = 0.15
endif
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, -offset, text)
else
call plptex(dx, dy, -dx, -dy, (1.d0 + offset), 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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