1 #!/usr/bin/env python \r
2 '''\r
3 Copyright (C) 2007 Tavmjong Bah, tavmjong@free.fr\r
4 Copyright (C) 2006 Georg Wiora, xorx@quarkbox.de\r
5 Copyright (C) 2006 Johan Engelen, johan@shouraizou.nl\r
6 Copyright (C) 2005 Aaron Spike, aaron@ekips.org\r
7 \r
8 This program is free software; you can redistribute it and/or modify\r
9 it under the terms of the GNU General Public License as published by\r
10 the Free Software Foundation; either version 2 of the License, or\r
11 (at your option) any later version.\r
12 \r
13 This program is distributed in the hope that it will be useful,\r
14 but WITHOUT ANY WARRANTY; without even the implied warranty of\r
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the\r
16 GNU General Public License for more details.\r
17 \r
18 You should have received a copy of the GNU General Public License\r
19 along with this program; if not, write to the Free Software\r
20 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA\r
21 \r
22 Changes:\r
23 * This program is a modified version of wavy.py by Aaron Spike.\r
24 * 22-Dec-2006: Wiora : Added axis and isotropic scaling\r
25 * 21-Jun-2007: Tavmjong: Added polar coordinates\r
26 \r
27 '''\r
28 import inkex, simplepath, simplestyle\r
29 from math import *\r
30 from random import *\r
31 \r
32 def drawfunction(xstart, xend, ybottom, ytop, samples, width, height, left, bottom, \r
33 fx = "sin(x)", fpx = "cos(x)", fponum = True, times2pi = False, polar = False, isoscale = True, drawaxis = True):\r
34 \r
35 if times2pi == True:\r
36 xstart = 2 * pi * xstart\r
37 xend = 2 * pi * xend \r
38 \r
39 # coords and scales based on the source rect\r
40 scalex = width / (xend - xstart)\r
41 xoff = left\r
42 coordx = lambda x: (x - xstart) * scalex + xoff #convert x-value to coordinate\r
43 if polar : # Set scale so that left side of rectangle is -1, right side is +1.\r
44 # (We can't use xscale for both range and scale.)\r
45 centerx = left + width/2.0\r
46 polar_scalex = width/2.0\r
47 coordx = lambda x: x * polar_scalex + centerx #convert x-value to coordinate\r
48 \r
49 scaley = height / (ytop - ybottom)\r
50 yoff = bottom\r
51 coordy = lambda y: (ybottom - y) * scaley + yoff #convert y-value to coordinate\r
52 \r
53 # Check for isotropic scaling and use smaller of the two scales, correct ranges\r
54 if isoscale and not polar:\r
55 if scaley<scalex:\r
56 # compute zero location\r
57 xzero = coordx(0)\r
58 # set scale\r
59 scalex = scaley\r
60 # correct x-offset\r
61 xstart = (left-xzero)/scalex\r
62 xend = (left+width-xzero)/scalex\r
63 else :\r
64 # compute zero location\r
65 yzero = coordy(0)\r
66 # set scale\r
67 scaley = scalex\r
68 # correct x-offset\r
69 ybottom = (yzero-bottom)/scaley\r
70 ytop = (bottom+height-yzero)/scaley\r
71 \r
72 # functions specified by the user\r
73 if fx != "":\r
74 f = eval('lambda x: ' + fx.strip('"'))\r
75 if fpx != "":\r
76 fp = eval('lambda x: ' + fpx.strip('"'))\r
77 \r
78 # step is the distance between nodes on x\r
79 step = (xend - xstart) / (samples-1)\r
80 third = step / 3.0\r
81 ds = step * 0.001 # Step used in calculating derivatives\r
82 \r
83 a = [] # path array \r
84 # add axis\r
85 if drawaxis :\r
86 # check for visibility of x-axis\r
87 if ybottom<=0 and ytop>=0:\r
88 # xaxis\r
89 a.append(['M ',[left, coordy(0)]])\r
90 a.append([' l ',[width, 0]])\r
91 # check for visibility of y-axis\r
92 if xstart<=0 and xend>=0:\r
93 # xaxis\r
94 a.append([' M ',[coordx(0),bottom]])\r
95 a.append([' l ',[0, -height]])\r
96 \r
97 # initialize function and derivative for 0;\r
98 # they are carried over from one iteration to the next, to avoid extra function calculations. \r
99 x0 = xstart\r
100 y0 = f(xstart)\r
101 if polar :\r
102 xp0 = y0 * cos( x0 )\r
103 yp0 = y0 * sin( x0 )\r
104 x0 = xp0\r
105 y0 = yp0\r
106 if fponum or polar: # numerical derivative, using 0.001*step as the small differential\r
107 x1 = xstart + ds # Second point AFTER first point (Good for first point)\r
108 y1 = f(x1)\r
109 if polar :\r
110 xp1 = y1 * cos( x1 )\r
111 yp1 = y1 * sin( x1 )\r
112 x1 = xp1\r
113 y1 = yp1\r
114 dx0 = (x1 - x0)/ds \r
115 dy0 = (y1 - y0)/ds\r
116 else: # derivative given by the user\r
117 dx0 = 0 # Only works for rectangular coordinates\r
118 dy0 = fp(xstart)\r
119 \r
120 # Start curve\r
121 a.append([' M ',[coordx(x0), coordy(y0)]]) # initial moveto\r
122 \r
123 for i in range(int(samples-1)):\r
124 x1 = (i+1) * step + xstart\r
125 x2 = x1 - ds # Second point BEFORE first point (Good for last point)\r
126 y1 = f(x1)\r
127 y2 = f(x2)\r
128 if polar :\r
129 xp1 = y1 * cos( x1 )\r
130 yp1 = y1 * sin( x1 )\r
131 xp2 = y2 * cos( x2 )\r
132 yp2 = y2 * sin( x2 )\r
133 x1 = xp1\r
134 y1 = yp1\r
135 x2 = xp2\r
136 y2 = yp2\r
137 if fponum or polar: # numerical derivative\r
138 dx1 = (x1 - x2)/ds\r
139 dy1 = (y1 - y2)/ds\r
140 else: # derivative given by the user\r
141 dx1 = 0 # Only works for rectangular coordinates\r
142 dy1 = fp(x1)\r
143 # create curve\r
144 a.append([' C ',\r
145 [coordx(x0 + (dx0 * third)), coordy(y0 + (dy0 * third)), \r
146 coordx(x1 - (dx1 * third)), coordy(y1 - (dy1 * third)),\r
147 coordx(x1), coordy(y1)]\r
148 ])\r
149 x0 = x1 # Next segment's start is this segments end\r
150 y0 = y1\r
151 dx0 = dx1 # Assume the function is smooth everywhere, so carry over the derivative too\r
152 dy0 = dy1 \r
153 return a\r
154 \r
155 class FuncPlot(inkex.Effect):\r
156 def __init__(self):\r
157 inkex.Effect.__init__(self)\r
158 self.OptionParser.add_option("--xstart",\r
159 action="store", type="float", \r
160 dest="xstart", default=0.0,\r
161 help="Start x-value")\r
162 self.OptionParser.add_option("--xend",\r
163 action="store", type="float", \r
164 dest="xend", default=1.0,\r
165 help="End x-value")\r
166 self.OptionParser.add_option("--times2pi",\r
167 action="store", type="inkbool", \r
168 dest="times2pi", default=True,\r
169 help="Multiply x-range by 2*pi") \r
170 self.OptionParser.add_option("--polar",\r
171 action="store", type="inkbool", \r
172 dest="polar", default=False,\r
173 help="Plot using polar coordinates") \r
174 self.OptionParser.add_option("--ybottom",\r
175 action="store", type="float", \r
176 dest="ybottom", default=-1.0,\r
177 help="y-value of rectangle's bottom")\r
178 self.OptionParser.add_option("--ytop",\r
179 action="store", type="float", \r
180 dest="ytop", default=1.0,\r
181 help="y-value of rectangle's top")\r
182 self.OptionParser.add_option("-s", "--samples",\r
183 action="store", type="int", \r
184 dest="samples", default=8,\r
185 help="Samples") \r
186 self.OptionParser.add_option("--fofx",\r
187 action="store", type="string", \r
188 dest="fofx", default="sin(x)",\r
189 help="f(x) for plotting") \r
190 self.OptionParser.add_option("--fponum",\r
191 action="store", type="inkbool", \r
192 dest="fponum", default=True,\r
193 help="Calculate the first derivative numerically") \r
194 self.OptionParser.add_option("--fpofx",\r
195 action="store", type="string", \r
196 dest="fpofx", default="cos(x)",\r
197 help="f'(x) for plotting") \r
198 self.OptionParser.add_option("--remove",\r
199 action="store", type="inkbool", \r
200 dest="remove", default=True,\r
201 help="If True, source rectangle is removed") \r
202 self.OptionParser.add_option("--isoscale",\r
203 action="store", type="inkbool", \r
204 dest="isoscale", default=True,\r
205 help="If True, isotropic scaling is used") \r
206 self.OptionParser.add_option("--drawaxis",\r
207 action="store", type="inkbool", \r
208 dest="drawaxis", default=True,\r
209 help="If True, axis are drawn") \r
210 self.OptionParser.add_option("--tab",\r
211 action="store", type="string", \r
212 dest="tab", default="sampling",\r
213 help="The selected UI-tab when OK was pressed") \r
214 self.OptionParser.add_option("--funcplotuse",\r
215 action="store", type="string", \r
216 dest="funcplotuse", default="",\r
217 help="dummy") \r
218 self.OptionParser.add_option("--pythonfunctions",\r
219 action="store", type="string", \r
220 dest="pythonfunctions", default="",\r
221 help="dummy") \r
222 \r
223 def effect(self):\r
224 for id, node in self.selected.iteritems():\r
225 if node.tag == inkex.addNS('rect','svg'):\r
226 # create new path with basic dimensions of selected rectangle\r
227 newpath = inkex.etree.Element(inkex.addNS('path','svg'))\r
228 x = float(node.get('x'))\r
229 y = float(node.get('y'))\r
230 w = float(node.get('width'))\r
231 h = float(node.get('height'))\r
232 \r
233 #copy attributes of rect\r
234 s = node.get('style')\r
235 if s:\r
236 newpath.set('style', s)\r
237 \r
238 t = node.get('transform')\r
239 if t:\r
240 newpath.set('transform', t)\r
241 \r
242 # top and bottom were exchanged\r
243 newpath.set('d', simplepath.formatPath(\r
244 drawfunction(self.options.xstart,\r
245 self.options.xend,\r
246 self.options.ybottom,\r
247 self.options.ytop,\r
248 self.options.samples, \r
249 w,h,x,y+h,\r
250 self.options.fofx, \r
251 self.options.fpofx,\r
252 self.options.fponum,\r
253 self.options.times2pi,\r
254 self.options.polar,\r
255 self.options.isoscale,\r
256 self.options.drawaxis)))\r
257 newpath.set('title', self.options.fofx)\r
258 \r
259 #newpath.setAttribute('desc', '!func;' + self.options.fofx + ';' \r
260 # + self.options.fpofx + ';'\r
261 # + `self.options.fponum` + ';'\r
262 # + `self.options.xstart` + ';'\r
263 # + `self.options.xend` + ';'\r
264 # + `self.options.samples`)\r
265 \r
266 # add path into SVG structure\r
267 node.getparent().append(newpath)\r
268 # option wether to remove the rectangle or not.\r
269 if self.options.remove:\r
270 node.getparent().remove(node)\r
271 \r
272 e = FuncPlot()\r
273 e.affect()\r