1nf.mac is from the book "Perturbation Methods, Bifurcation Theory and
2Computer Algebra" by Rand & Armbruster (Springer 1987)
3
4This maxima run applies normal forms to a system of equations.  The
5functions NF, GEN, DECOMPOSE, HOPF2, HOPF3 and TRANSFORM are
6used.
7
8The example is from p55-62.  It is presented without discussion.
9maxima-5.9.0 cvs reproduces the results from the book.
10
11(C1) load("./nf.mac");
12(D1)                               ./nf.mac
13(C2) load("./transfor.mac");
14(D2)                            ./transfor.mac
15(C3) nf();
16DO YOU WANT TO ENTER NEW VARIABLE NAMES (Y/N)?
17y;
18HOW MANY EQS
192;
20SYMBOL FOR OLD X[ 1 ]
21x;
22SYMBOL FOR OLD X[ 2 ]
23y;
24SYMBOL FOR NEW X[ 1 ]
25u;
26SYMBOL FOR NEW X[ 2 ]
27v;
28DO YOU WANT TO ENTER NEW D.E.'S (Y/N)?
29y;
30ENTER RHS OF EQ. NO. 1 ,D x /DT =
31-y+fxx/2*x^2+fxy*x*y+fyy/2*y^2+fxxx/6*x^3+fxxy/2*x^2*y+fxyy/2*x*y^2+fyyy/6*y^3;
32                3           2        2         2                         3
33          fyyy y    fxyy x y    fyy y    fxxy x  y                 fxxx x
34D x /DT = ------- + --------- + ------ + --------- + fxy x y - y + -------
35             6          2         2          2                        6
36
37                                                                             2
38                                                                        fxx x
39                                                                      + ------
40                                                                          2
41ENTER RHS OF EQ. NO. 2 ,D y /DT =
42x+gxx/2*x^2+gxy*x*y+gyy/2*y^2+gxxx/6*x^3+gxxy/2*x^2*y+gxyy/2*x*y^2+gyyy/6*y^3;
43                3           2        2         2                     3        2
44          gyyy y    gxyy x y    gyy y    gxxy x  y             gxxx x    gxx x
45D y /DT = ------- + --------- + ------ + --------- + gxy x y + ------- + ------
46             6          2         2          2                    6        2
47
48                                                                           + x
49INPUT NEAR-IDENTITY TRANSFORMATION
50
51(USE PREV FOR PREVIOUS TRANSFORMATION)
52x = u + ?
53gen(2);
54                2                                2
55x = A          v  + A          u v + A          u  + u
56     1, [0, 2]       1, [1, 1]        1, [2, 0]
57y = v + ?
58gen(2);
59                2                                    2
60y = A          v  + A          u v + v + A          u
61     2, [0, 2]       2, [1, 1]            2, [2, 0]
62ENTER TRUNCATION ORDER (HIGHEST ORDER TERMS TO BE KEPT)
632;
64du                                               2
65-- = - v - ((2 A          + 2 A          - fxx) u
66dT              2, [2, 0]      1, [1, 1]
67
68 + (2 A          - 4 A          + 4 A          - 2 fxy) v u
69       2, [1, 1]      1, [2, 0]      1, [0, 2]
70
71                                        2
72 + (2 A          - 2 A          - fyy) v )/2 + . . .
73       2, [0, 2]      1, [1, 1]
74dv                                             2
75-- = u - ((2 A          - 2 A          - gxx) u
76dT            2, [1, 1]      1, [2, 0]
77
78 + (- 4 A          + 4 A          - 2 A          - 2 gxy) v u
79         2, [2, 0]      2, [0, 2]      1, [1, 1]
80
81                                          2
82 + (- 2 A          - 2 A          - gyy) v )/2 + . . .
83         2, [1, 1]      1, [0, 2]
84DO YOU WANT TO ENTER ANOTHER TRANSFORMATION (Y/N)
85n;
86         du                                               2
87(D3)/T/ [-- = - v - ((2 A          + 2 A          - fxx) u
88         dT              2, [2, 0]      1, [1, 1]
89
90 + (2 A          - 4 A          + 4 A          - 2 fxy) v u
91       2, [1, 1]      1, [2, 0]      1, [0, 2]
92
93                                        2
94 + (2 A          - 2 A          - fyy) v )/2 + . . .,
95       2, [0, 2]      1, [1, 1]
96
97dv                                             2
98-- = u - ((2 A          - 2 A          - gxx) u
99dT            2, [1, 1]      1, [2, 0]
100
101 + (- 4 A          + 4 A          - 2 A          - 2 gxy) v u
102         2, [2, 0]      2, [0, 2]      1, [1, 1]
103
104                                          2
105 + (- 2 A          - 2 A          - gyy) v )/2 + . . .]
106         2, [1, 1]      1, [0, 2]
107
108
109(C4) hopf2();
110                      2 gyy + gxx + 2 fxy               - 2 gxy + 2 fyy + fxx
111(D4) [[A          = - -------------------, A          = ---------------------,
112        1, [2, 0]              6            2, [2, 0]             6
113
114             gxy - fyy + fxx                 gyy - gxx + fxy
115A          = ---------------, A          = - ---------------,
116 1, [1, 1]          3          2, [1, 1]            3
117
118             - gyy - 2 gxx + 2 fxy               2 gxy + fyy + 2 fxx
119A          = ---------------------, A          = -------------------]]
120 1, [0, 2]             6             2, [0, 2]            6
121
122
123
124(C5) nf();
125DO YOU WANT TO ENTER NEW VARIABLE NAMES (Y/N)?
126N;
127DO YOU WANT TO ENTER NEW D.E.'S (Y/N)?
128N;
129INPUT NEAR-IDENTITY TRANSFORMATION
130
131(USE PREV FOR PREVIOUS TRANSFORMATION)
132x = u + ?
133ev(prev,%);
134                             2
135    (- gyy - 2 gxx + 2 fxy) v    (gxy - fyy + fxx) u v
136x = -------------------------- + ---------------------
137                6                          3
138
139                                                                         2
140                                                  (2 gyy + gxx + 2 fxy) u
141                                                - ------------------------ + u
142                                                             6
143y = v + ?
144ev(prev,%);
145                           2
146    (2 gxy + fyy + 2 fxx) v    (gyy - gxx + fxy) u v
147y = ------------------------ - --------------------- + v
148               6                         3
149
150                                                                             2
151                                                    (- 2 gxy + 2 fyy + fxx) u
152                                                  + --------------------------
153                                                                6
154ENTER TRUNCATION ORDER (HIGHEST ORDER TERMS TO BE KEPT)
1552;
156du
157-- = - v + . . .
158dT
159dv
160-- = u + . . .
161dT
162DO YOU WANT TO ENTER ANOTHER TRANSFORMATION (Y/N)
163Y;
164INPUT NEAR-IDENTITY TRANSFORMATION
165
166(USE PREV FOR PREVIOUS TRANSFORMATION)
167x = u + ?
168prev+gen(3);
169                                                               2
170                3                 2   (- gyy - 2 gxx + 2 fxy) v
171x = A          v  + A          u v  + --------------------------
172     1, [0, 3]       1, [1, 2]                    6
173
174               2     (gxy - fyy + fxx) u v               3
175 + A          u  v + --------------------- + A          u
176    1, [2, 1]                  3              1, [3, 0]
177
178                          2
179   (2 gyy + gxx + 2 fxy) u
180 - ------------------------ + u
181              6
182y = v + ?
183prev+gen(3);
184                                                             2
185                3                 2   (2 gxy + fyy + 2 fxx) v
186y = A          v  + A          u v  + ------------------------
187     2, [0, 3]       2, [1, 2]                   6
188
189               2     (gyy - gxx + fxy) u v                   3
190 + A          u  v - --------------------- + v + A          u
191    2, [2, 1]                  3                  2, [3, 0]
192
193                            2
194   (- 2 gxy + 2 fyy + fxx) u
195 + --------------------------
196               6
197ENTER TRUNCATION ORDER (HIGHEST ORDER TERMS TO BE KEPT)
1983;
199du
200-- = - v - (((fxy + gxx + 2 gyy) fxx - 2 fxy fyy + 2 fxy gxy + 6 A
201dT                                                                2, [3, 0]
202
203                         3           2                            2
204 + 6 A          - fxxx) u  + (- 2 fxx  + (fyy - 2 gxy) fxx - 2 fyy  + 2 gxy fyy
205      1, [2, 1]
206
207        2
208 + 4 fxy  + (- gxx + 4 gyy) fxy + 6 A          - 18 A          + 12 A
209                                     2, [2, 1]       1, [3, 0]       1, [1, 2]
210
211              2
212 - 3 fxxy) v u  + ((- 6 fxy + 2 gxx + gyy) fxx + (3 fxy - 2 gxx + 2 gyy) fyy
213
214                                                                       2
215 - 4 fxy gxy + 6 A          - 12 A          + 18 A          - 3 fxyy) v  u
216                  2, [1, 2]       1, [2, 1]       1, [0, 3]
217
218                     2                    2
219 + (- 2 fyy fxx - fyy  - 2 gxy fyy - 2 fxy  + (2 gxx + gyy) fxy + 6 A
220                                                                     2, [0, 3]
221
222                         3
223 - 6 A          - fyyy) v )/6 + . . .
224      1, [1, 2]
225dv                                    2                  2
226-- = u + ((gxy fxx + 2 gxy fyy - 2 gxy  - 2 gxx fxy - gxx  - 2 gyy gxx
227dT
228
229                                        3
230 - 6 A          + 6 A          + gxxx) u
231      2, [2, 1]      1, [3, 0]
232
233 + ((2 gxx + gyy) fxx + (- 2 gxx + 2 gyy) fyy + (- 4 fxy + 3 gxx - 6 gyy) gxy
234
235                                                             2
236 + 18 A          - 12 A          + 6 A          + 3 gxxy) v u
237       2, [3, 0]       2, [1, 2]      1, [2, 1]
238
239                               2                              2
240 + (4 gxy fxx - gxy fyy + 4 gxy  + (2 gxx - 2 gyy) fxy - 2 gxx  + gyy gxx
241
242        2                                                           2
243 - 2 gyy  + 12 A          - 18 A          + 6 A          + 3 gxyy) v  u
244                2, [2, 1]       2, [0, 3]      1, [1, 2]
245
246 + (2 gyy fxx + gyy fyy + (2 fxy - 2 gxx + gyy) gxy + 6 A
247                                                         2, [1, 2]
248
249                         3
250 + 6 A          + gyyy) v )/6 + . . .
251      1, [0, 3]
252DO YOU WANT TO ENTER ANOTHER TRANSFORMATION (Y/N)
253N;
254         du
255(D5)/T/ [-- = - v - (((fxy + gxx + 2 gyy) fxx - 2 fxy fyy + 2 fxy gxy
256         dT
257
258                                        3
259 + 6 A          + 6 A          - fxxx) u
260      2, [3, 0]      1, [2, 1]
261
262           2                            2                    2
263 + (- 2 fxx  + (fyy - 2 gxy) fxx - 2 fyy  + 2 gxy fyy + 4 fxy
264
265 + (- gxx + 4 gyy) fxy + 6 A          - 18 A          + 12 A          - 3 fxxy)
266                            2, [2, 1]       1, [3, 0]       1, [1, 2]
267
268    2
269 v u  + ((- 6 fxy + 2 gxx + gyy) fxx + (3 fxy - 2 gxx + 2 gyy) fyy - 4 fxy gxy
270
271                                                           2
272 + 6 A          - 12 A          + 18 A          - 3 fxyy) v  u
273      2, [1, 2]       1, [2, 1]       1, [0, 3]
274
275                     2                    2
276 + (- 2 fyy fxx - fyy  - 2 gxy fyy - 2 fxy  + (2 gxx + gyy) fxy + 6 A
277                                                                     2, [0, 3]
278
279                         3
280 - 6 A          - fyyy) v )/6 + . . .,
281      1, [1, 2]
282
283dv                                    2                  2
284-- = u + ((gxy fxx + 2 gxy fyy - 2 gxy  - 2 gxx fxy - gxx  - 2 gyy gxx
285dT
286
287                                        3
288 - 6 A          + 6 A          + gxxx) u
289      2, [2, 1]      1, [3, 0]
290
291 + ((2 gxx + gyy) fxx + (- 2 gxx + 2 gyy) fyy + (- 4 fxy + 3 gxx - 6 gyy) gxy
292
293                                                             2
294 + 18 A          - 12 A          + 6 A          + 3 gxxy) v u
295       2, [3, 0]       2, [1, 2]      1, [2, 1]
296
297                               2                              2
298 + (4 gxy fxx - gxy fyy + 4 gxy  + (2 gxx - 2 gyy) fxy - 2 gxx  + gyy gxx
299
300        2                                                           2
301 - 2 gyy  + 12 A          - 18 A          + 6 A          + 3 gxyy) v  u
302                2, [2, 1]       2, [0, 3]      1, [1, 2]
303
304 + (2 gyy fxx + gyy fyy + (2 fxy - 2 gxx + gyy) gxy + 6 A
305                                                         2, [1, 2]
306
307                         3
308 + 6 A          + gyyy) v )/6 + . . .]
309      1, [0, 3]
310
311
312(C6) hopf3();
313                          2                                     2
314(D6) [[A          = (2 gyy  + (gxx + 7 fxy) gyy - 3 gxyy - 2 gxy
315        1, [3, 0]
316
317                                     2                         2
318 + (- fyy - 7 fxx) gxy - gxxx + 3 gxx  + fxy gxx - fyyy - 3 fyy  - fxx fyy
319
320        2                 2
321 + 2 fxy  - 3 fxxy - 2 fxx  + 24 %R1)/24, A          = %R2,
322                                           2, [3, 0]
323
324A          = (- 3 gyyy + (3 gxy - 3 fyy - 16 fxx) gyy + (3 gxx - 16 fxy) gxy
325 1, [2, 1]
326
327 - 3 gxxy - 5 fxx gxx + 13 fxy fyy - 3 fxyy - 11 fxx fxy + 5 fxxx - 48 %R2)
328
329                        2                                        2
330/48, A          = (6 gyy  + (9 fxy - 9 gxx) gyy - 9 gxyy - 18 gxy
331      2, [2, 1]
332
333                                         2                          2
334 + (13 fyy - 11 fxx) gxy + 3 gxxx + 3 gxx  - 15 fxy gxx + fyyy - fyy
335
336                    2                 2
337 + 3 fxx fyy + 6 fxy  - 3 fxxy - 2 fxx  + 48 %R1)/48,
338
339                   2                                       2
340A          = (2 gyy  + (5 gxx + 3 fxy) gyy - 3 gxyy + 2 gxy
341 1, [1, 2]
342
343                                          2                              2
344 + (- 17 fyy - 5 fxx) gxy - 3 gxxx + 5 gxx  + 15 fxy gxx - 5 fyyy - 3 fyy
345
346                      2                 2
347 - 11 fxx fyy - 14 fxy  + 3 fxxy + 2 fxx  + 48 %R1)/48,
348
349A          = - (3 gyyy + (21 gxy - 5 fyy + 4 fxx) gyy + (24 fxy - 15 gxx) gxy
350 2, [1, 2]
351
352 - 9 gxxy + (8 fyy - 7 fxx) gxx - 5 fxy fyy + 3 fxyy + 7 fxx fxy - fxxx
353
354 - 48 %R2)/48, A          = (- gyyy + (5 gxy - 5 fyy - 6 fxx) gyy
355                1, [0, 3]
356
357 + (4 fxy - gxx) gxy - 3 gxxy + (4 fyy - 5 fxx) gxx - fxy fyy + 3 fxyy
358
359 + 5 fxx fxy + fxxx - 24 %R2)/24, A          = %R1]]
360                                   2, [0, 3]
361
362
363(C7) expand(ev(newdes,%));
364              2  3              3              3         3      2  3
365      du   gyy  v    5 gxx gyy v    5 fxy gyy v    gxyy v    gxy  v
366(D7) [-- = ------- + ------------ - ------------ - ------- + -------
367      dT     24           48             48          16        24
368
369            3              3         3        2  3            3         3
370   fyy gxy v    5 fxx gxy v    gxxx v    5 gxx  v    fxy gxx v    fyyy v
371 - ---------- - ------------ - ------- + --------- - ---------- + -------
372       48            48          16         48           48         16
373
374        2  3              3      2  3         3      2  3           2
375   5 fyy  v    5 fxx fyy v    fxy  v    fxxy v    fxx  v    gyyy u v
376 + --------- + ------------ + ------- + ------- + ------- + ---------
377      48            48          24        16        24         16
378
379              2              2              2           2              2
380   gxy gyy u v    fyy gyy u v    gxx gxy u v    gxxy u v    fxx gxx u v
381 - ------------ + ------------ - ------------ + --------- - ------------
382        16             16             16           16            16
383
384              2           2              2           2      2  2
385   fxy fyy u v    fxyy u v    fxx fxy u v    fxxx u v    gyy  u  v
386 + ------------ + --------- + ------------ + --------- + ---------
387        16           16            16           16          24
388
389              2                2           2        2  2              2
390   5 gxx gyy u  v   5 fxy gyy u  v   gxyy u  v   gxy  u  v   fyy gxy u  v
391 + -------------- - -------------- - --------- + --------- - ------------
392         48               48            16          24            48
393
394              2           2          2  2              2           2
395   5 fxx gxy u  v   gxxx u  v   5 gxx  u  v   fxy gxx u  v   fyyy u  v
396 - -------------- - --------- + ----------- - ------------ + ---------
397         48            16           48             48           16
398
399        2  2                2        2  2           2        2  2
400   5 fyy  u  v   5 fxx fyy u  v   fxy  u  v   fxxy u  v   fxx  u  v
401 + ----------- + -------------- + --------- + --------- + --------- - v
402       48              48            24          16          24
403
404         3            3            3            3         3            3
405   gyyy u    gxy gyy u    fyy gyy u    gxx gxy u    gxxy u    fxx gxx u
406 + ------- - ---------- + ---------- - ---------- + ------- - ----------
407     16          16           16           16         16          16
408
409            3         3            3         3
410   fxy fyy u    fxyy u    fxx fxy u    fxxx u
411 + ---------- + ------- + ---------- + -------,
412       16         16          16         16
413
414           3            3            3            3         3            3
415dv   gyyy v    gxy gyy v    fyy gyy v    gxx gxy v    gxxy v    fxx gxx v
416-- = ------- - ---------- + ---------- - ---------- + ------- - ----------
417dT     16          16           16           16         16          16
418
419            3         3            3         3      2    2                2
420   fxy fyy v    fxyy v    fxx fxy v    fxxx v    gyy  u v    5 gxx gyy u v
421 + ---------- + ------- + ---------- + ------- - --------- - --------------
422       16         16          16         16         24             48
423
424                2           2      2    2              2                2
425   5 fxy gyy u v    gxyy u v    gxy  u v    fyy gxy u v    5 fxx gxy u v
426 + -------------- + --------- - --------- + ------------ + --------------
427         48            16          24            48              48
428
429           2        2    2              2           2        2    2
430   gxxx u v    5 gxx  u v    fxy gxx u v    fyyy u v    5 fyy  u v
431 + --------- - ----------- + ------------ - --------- - -----------
432      16           48             48           16           48
433
434                2      2    2           2      2    2         2
435   5 fxx fyy u v    fxy  u v    fxxy u v    fxx  u v    gyyy u  v
436 - -------------- - --------- - --------- - --------- + ---------
437         48            24          16          24          16
438
439            2              2              2           2              2
440   gxy gyy u  v   fyy gyy u  v   gxx gxy u  v   gxxy u  v   fxx gxx u  v
441 - ------------ + ------------ - ------------ + --------- - ------------
442        16             16             16           16            16
443
444            2           2              2           2        2  3              3
445   fxy fyy u  v   fxyy u  v   fxx fxy u  v   fxxx u  v   gyy  u    5 gxx gyy u
446 + ------------ + --------- + ------------ + --------- - ------- - ------------
447        16           16            16           16         24           48
448
449              3         3      2  3            3              3         3
450   5 fxy gyy u    gxyy u    gxy  u    fyy gxy u    5 fxx gxy u    gxxx u
451 + ------------ + ------- - ------- + ---------- + ------------ + -------
452        48          16        24          48            48          16
453
454        2  3            3         3        2  3              3      2  3
455   5 gxx  u    fxy gxx u    fyyy u    5 fyy  u    5 fxx fyy u    fxy  u
456 - --------- + ---------- - ------- - --------- - ------------ - -------
457      48           48         16         48            48          24
458
459         3      2  3
460   fxxy u    fxx  u
461 - ------- - ------- + u]
462     16        24
463
464(C8) transform();
465ENTER NUMBER OF EQUATIONS
4662;
467ENTER SYMBOL FOR ORIGINAL VARIABLE 1
468u;
469ENTER SYMBOL FOR ORIGINAL VARIABLE 2
470v;
471ENTER SYMBOL FOR TRANSFORMED VARIABLE 1
472r;
473ENTER SYMBOL FOR TRANSFORMED VARIABLE 2
474theta;
475THE RHS'S OF THE D.E.'S ARE FUNCTIONS OF THE ORIGINAL VARIABLES:
476ENTER RHS OF u D.E.
477D u /DT =
478rhs(part(%,1));
479             2  3              3              3         3      2  3
480          gyy  v    5 gxx gyy v    5 fxy gyy v    gxyy v    gxy  v
481D u /DT = ------- + ------------ - ------------ - ------- + -------
482            24           48             48          16        24
483
484            3              3         3        2  3            3         3
485   fyy gxy v    5 fxx gxy v    gxxx v    5 gxx  v    fxy gxx v    fyyy v
486 - ---------- - ------------ - ------- + --------- - ---------- + -------
487       48            48          16         48           48         16
488
489        2  3              3      2  3         3      2  3           2
490   5 fyy  v    5 fxx fyy v    fxy  v    fxxy v    fxx  v    gyyy u v
491 + --------- + ------------ + ------- + ------- + ------- + ---------
492      48            48          24        16        24         16
493
494              2              2              2           2              2
495   gxy gyy u v    fyy gyy u v    gxx gxy u v    gxxy u v    fxx gxx u v
496 - ------------ + ------------ - ------------ + --------- - ------------
497        16             16             16           16            16
498
499              2           2              2           2      2  2
500   fxy fyy u v    fxyy u v    fxx fxy u v    fxxx u v    gyy  u  v
501 + ------------ + --------- + ------------ + --------- + ---------
502        16           16            16           16          24
503
504              2                2           2        2  2              2
505   5 gxx gyy u  v   5 fxy gyy u  v   gxyy u  v   gxy  u  v   fyy gxy u  v
506 + -------------- - -------------- - --------- + --------- - ------------
507         48               48            16          24            48
508
509              2           2          2  2              2           2
510   5 fxx gxy u  v   gxxx u  v   5 gxx  u  v   fxy gxx u  v   fyyy u  v
511 - -------------- - --------- + ----------- - ------------ + ---------
512         48            16           48             48           16
513
514        2  2                2        2  2           2        2  2
515   5 fyy  u  v   5 fxx fyy u  v   fxy  u  v   fxxy u  v   fxx  u  v
516 + ----------- + -------------- + --------- + --------- + --------- - v
517       48              48            24          16          24
518
519         3            3            3            3         3            3
520   gyyy u    gxy gyy u    fyy gyy u    gxx gxy u    gxxy u    fxx gxx u
521 + ------- - ---------- + ---------- - ---------- + ------- - ----------
522     16          16           16           16         16          16
523
524            3         3            3         3
525   fxy fyy u    fxyy u    fxx fxy u    fxxx u
526 + ---------- + ------- + ---------- + -------
527       16         16          16         16
528ENTER RHS OF v D.E.
529D v /DT =
530rhs(part(%,2));
531                3            3            3            3         3            3
532          gyyy v    gxy gyy v    fyy gyy v    gxx gxy v    gxxy v    fxx gxx v
533D v /DT = ------- - ---------- + ---------- - ---------- + ------- - ----------
534            16          16           16           16         16          16
535
536            3         3            3         3      2    2                2
537   fxy fyy v    fxyy v    fxx fxy v    fxxx v    gyy  u v    5 gxx gyy u v
538 + ---------- + ------- + ---------- + ------- - --------- - --------------
539       16         16          16         16         24             48
540
541                2           2      2    2              2                2
542   5 fxy gyy u v    gxyy u v    gxy  u v    fyy gxy u v    5 fxx gxy u v
543 + -------------- + --------- - --------- + ------------ + --------------
544         48            16          24            48              48
545
546           2        2    2              2           2        2    2
547   gxxx u v    5 gxx  u v    fxy gxx u v    fyyy u v    5 fyy  u v
548 + --------- - ----------- + ------------ - --------- - -----------
549      16           48             48           16           48
550
551                2      2    2           2      2    2         2
552   5 fxx fyy u v    fxy  u v    fxxy u v    fxx  u v    gyyy u  v
553 - -------------- - --------- - --------- - --------- + ---------
554         48            24          16          24          16
555
556            2              2              2           2              2
557   gxy gyy u  v   fyy gyy u  v   gxx gxy u  v   gxxy u  v   fxx gxx u  v
558 - ------------ + ------------ - ------------ + --------- - ------------
559        16             16             16           16            16
560
561            2           2              2           2        2  3              3
562   fxy fyy u  v   fxyy u  v   fxx fxy u  v   fxxx u  v   gyy  u    5 gxx gyy u
563 + ------------ + --------- + ------------ + --------- - ------- - ------------
564        16           16            16           16         24           48
565
566              3         3      2  3            3              3         3
567   5 fxy gyy u    gxyy u    gxy  u    fyy gxy u    5 fxx gxy u    gxxx u
568 + ------------ + ------- - ------- + ---------- + ------------ + -------
569        48          16        24          48            48          16
570
571        2  3            3         3        2  3              3      2  3
572   5 gxx  u    fxy gxx u    fyyy u    5 fyy  u    5 fxx fyy u    fxy  u
573 - --------- + ---------- - ------- - --------- - ------------ - -------
574      48           48         16         48            48          24
575
576         3      2  3
577   fxxy u    fxx  u
578 - ------- - ------- + u
579     16        24
580THE TRANSFORMATION IS ENTERED NEXT:
581ENTER u AS A FUNCTION OF THE NEW VARIABLES
582u =
583r*cos(theta);
584u = r COS(THETA)
585ENTER v AS A FUNCTION OF THE NEW VARIABLES
586v =
587r*sin(theta);
588v = r SIN(THETA)
589       dr
590(D8) [[-- = ((gyyy + (fyy - gxy) gyy - gxx gxy + gxxy - fxx gxx + fxy fyy
591       dT
592
593                           3    2
594 + fxyy + fxx fxy + fxxx) r  SIN (THETA)
595
596 + (gyyy + (fyy - gxy) gyy - gxx gxy + gxxy - fxx gxx + fxy fyy + fxyy
597
598                    3    2
599 + fxx fxy + fxxx) r  COS (THETA))/16,
600
601dTHETA            2                                       2
602------ = - ((2 gyy  + (5 gxx - 5 fxy) gyy - 3 gxyy + 2 gxy
603  dT
604
605                                       2                           2
606 + (- fyy - 5 fxx) gxy - 3 gxxx + 5 gxx  - fxy gxx + 3 fyyy + 5 fyy
607
608                    2                 2   2    2
609 + 5 fxx fyy + 2 fxy  + 3 fxxy + 2 fxx ) r  SIN (THETA)
610
611         2                                       2
612 + (2 gyy  + (5 gxx - 5 fxy) gyy - 3 gxyy + 2 gxy  + (- fyy - 5 fxx) gxy
613
614                 2                           2                    2
615 - 3 gxxx + 5 gxx  - fxy gxx + 3 fyyy + 5 fyy  + 5 fxx fyy + 2 fxy  + 3 fxxy
616
617        2   2    2
618 + 2 fxx ) r  COS (THETA) - 48)/48]]
619
620
621(C9) trigsimp(%);
622       dr
623(D9) [[-- = (gyyy + (fyy - gxy) gyy - gxx gxy + gxxy - fxx gxx + fxy fyy + fxyy
624       dT
625
626                    3     dTHETA            2
627 + fxx fxy + fxxx) r /16, ------ = - ((2 gyy  + (5 gxx - 5 fxy) gyy - 3 gxyy
628                            dT
629
630        2                                       2                           2
631 + 2 gxy  + (- fyy - 5 fxx) gxy - 3 gxxx + 5 gxx  - fxy gxx + 3 fyyy + 5 fyy
632
633                    2                 2   2
634 + 5 fxx fyy + 2 fxy  + 3 fxxy + 2 fxx ) r  - 48)/48]]
635
636
637
638Local Variables: ***
639mode: Text ***
640End: ***