MaplePrimes Questions

Hi Everybody,

I have a simple question: Does Maple solve systems of partial differential equations with boundary conditions?

Can somebody give me an example? 

I have only found numerical solutions to this kind of systems but no symbolic example.

Thanks a lot for yor help.

 

To my amazement, the following code hangs

restart:
with(Physics):
Physics:-Version();
Setup(anticommutativeprefix = psi):
Dagger(psi);

at the last line, or produces the output "Error, (in sprintf) too many levels of recursion" if I wait long enough.

What is going on? Am I just being stupid? The version line verifies to me that I am using the Physics package as shipped with Maple 2017, version date 17th of May 2017. If I outcomment the Setup line, then Dagger does not hang. Do others experience the same behaviour?

Hey,

I am using codegen to generate code from Maple expressions. More specifically I want to export non quadratic matix. The export works for matrices that have more columns than rows, but not for matrices with more rows than columns. There I receive the error:

Error, (in codegen/array/entry) 2nd index, 3, larger than upper array bound 2

A workaround would be to transpose the matrix before the export, and to transpose on the import (in Matlab) but I don't want to overcomplicate my code. Thanks for your help!

I have attached a demonstration worksheet below.

 

## test codegen non quadratic returnarray

## works
#Myfun := Matrix(3,3)

## works
#Myfun := Matrix(2,3):Myfun(2,3):= 3*b;

## does not work
Myfun := Matrix(3,2):Myfun(3,2):= 3*b;

Myfun := Matrix(3, 2, {(1, 1) = 0, (1, 2) = 0, (2, 1) = 0, (2, 2) = 0, (3, 1) = 0, (3, 2) = 3*b})

(1)

Myfun(1):= 7*a;

Myfun := Matrix(3, 2, {(1, 1) = 7*a, (1, 2) = 0, (2, 1) = 0, (2, 2) = 0, (3, 1) = 0, (3, 2) = 3*b})

(2)

## codegen works best with arraybased matrices, and call by reference becomes possible

returnArray:= convert(Myfun,matrix)

returnArray := Matrix(3, 2, {(1, 1) = 7*a, (1, 2) = 0, (2, 1) = 0, (2, 2) = 0, (3, 1) = 0, (3, 2) = 3*b})

(3)

codegen[makeproc](Myfun,[a,b])

Error, (in codegen/array/entry) 2nd index, 3, larger than upper array bound 2

 

codegen[makeproc](returnArray,[returnArray,a,b])

Error, (in codegen/array/entry) 2nd index, 3, larger than upper array bound 2

 

codegen[makeproc](returnArray,[a,b])

Error, (in codegen/array/entry) 2nd index, 3, larger than upper array bound 2

 

 


 

Download codegen_rectangular_matrix.mw

 

Hi, everybody.

I have a problem when I try to plot3d a sub-surface from a surface as follows:


 

S := proc (u, v) options operator, arrow; Matrix([[40*u], [80*v], [10*u^2*v+20*u*v+15]]) end proc;

proc (u, v) options operator, arrow; Matrix([[40*u], [80*v], [10*u^2*v+20*u*v+15]]) end proc

(1)

S(u, v)

Matrix(3, 1, {(1, 1) = 40*u, (2, 1) = 80*v, (3, 1) = 10*u^2*v+20*u*v+15})

(2)

 

p:= proc(u,v) if u<v then S(u,v) else S(u,v)+10 end if end proc:

h:= proc(u) 2*u  end proc:

plot3d(p, 0 .. 1, 0 .. h)

Warning, unable to evaluate the function to numeric values in the region; see the plotting command's help page to ensure the calling sequence is correct

 

 

``


 

Download sub-surface.mw

sub-surface.mw

 

Please help me!

 

Thanks and have a nice day.

 

 

how can i plot tangent function without its Asymptote on kPi/2s ? actuallt i want to plot without its vertical Asymptote, could anybody help? tnx
 

restart:

plot(tan(x),x=-2*Pi..2*Pi,style = line,color = "Blue",legend = "tangent Plot",axes=boxed,gridlines);

 

 


 

Download plot.mw

i want to know the area under a diagram plotted by pdsolve, how can i do that? for example in below , what is the area under p1 diagram?


 

restart:k:=5;

5

(1)

EQ:=diff(u(x,t),t)=k*diff(u(x,t),x$2);

diff(u(x, t), t) = 5*(diff(diff(u(x, t), x), x))

(2)

ibc:=u(0,t)=0,u(1,t)=0, u(x,0) = x;

u(0, t) = 0, u(1, t) = 0, u(x, 0) = x

(3)

sol:=pdsolve({EQ},{ibc},numeric);

_m2021168030176

(4)

p1:=sol:-plot(u,x=0.5,t=0...10,style = line,color = "Blue",legend = "heat Plot",axes=boxed);

 

M:=op(1,op(1,p1));

M := Array(1..201, 1..2, {(1, 1) = .0, (1, 2) = .5, (2, 1) = 0.5e-1, (2, 2) = .2702110502740721, (3, 1) = .1, (3, 2) = -0.176887059080428e-1, (4, 1) = .15, (4, 2) = -0.6515347962762406e-2, (5, 1) = .2, (5, 2) = 0.74109221595503715e-2, (6, 1) = .25, (6, 2) = -0.6178984348254404e-2, (7, 1) = .3, (7, 2) = 0.49645329554988925e-2, (8, 1) = .35, (8, 2) = -0.3948699801548904e-2, (9, 1) = .4, (9, 2) = 0.31161325326115076e-2, (10, 1) = .45, (10, 2) = -0.24369292293079273e-2, (11, 1) = .5, (11, 2) = 0.18845070914387395e-2, (12, 1) = .55, (12, 2) = -0.14366378752131666e-2, (13, 1) = .6, (13, 2) = 0.10748767238662861e-2, (14, 1) = .65, (14, 2) = -0.7839388660633711e-3, (15, 1) = .7, (15, 2) = 0.5511660027174686e-3, (16, 1) = .75, (16, 2) = -0.3660810752890637e-3, (17, 1) = .8, (17, 2) = 0.22001797006812284e-3, (18, 1) = .85, (18, 2) = -0.10581369353881973e-3, (19, 1) = .9, (19, 2) = 0.1755251750102873e-4, (20, 1) = .95, (20, 2) = 0.4964665498398858e-4, (21, 1) = 1.0, (21, 2) = -0.9980698165105276e-4, (22, 1) = 1.05, (22, 2) = 0.1362404856962589e-3, (23, 1) = 1.1, (23, 2) = -0.16167000912668705e-3, (24, 1) = 1.15, (24, 2) = 0.17833050358069153e-3, (25, 1) = 1.2, (25, 2) = -0.18805314257842951e-3, (26, 1) = 1.25, (26, 2) = 0.19233515285281392e-3, (27, 1) = 1.3, (27, 2) = -0.19239777469550633e-3, (28, 1) = 1.35, (28, 2) = 0.18923435555607597e-3, (29, 1) = 1.4, (29, 2) = -0.18365024366673088e-3, (30, 1) = 1.45, (30, 2) = 0.17629586775928352e-3, (31, 1) = 1.5, (31, 2) = -0.16769415545232156e-3, (32, 1) = 1.55, (32, 2) = 0.15826324867687376e-3, (33, 1) = 1.6, (33, 2) = -0.1483353129733858e-3, (34, 1) = 1.65, (34, 2) = 0.1381721031382132e-3, (35, 1) = 1.7, (35, 2) = -0.12797783595325005e-3, (36, 1) = 1.75, (36, 2) = 0.11790982779578369e-3, (37, 1) = 1.8, (37, 2) = -0.10808727763435372e-3, (38, 1) = 1.85, (38, 2) = 0.9859851163881829e-4, (39, 1) = 1.9, (39, 2) = -0.8950695218043435e-4, (40, 1) = 1.95, (40, 2) = 0.8085602954949057e-4, (41, 1) = 2.0, (41, 2) = -0.7267321775920382e-4, (42, 1) = 2.05, (42, 2) = 0.6497334507523223e-4, (43, 1) = 2.1, (43, 2) = -0.5776130436199765e-4, (44, 1) = 2.15, (44, 2) = 0.5103426709812118e-4, (45, 1) = 2.2, (45, 2) = -0.4478348725852213e-4, (46, 1) = 2.25, (46, 2) = 0.3899576658643508e-4, (47, 1) = 2.3, (47, 2) = -0.336546405833609e-4, (48, 1) = 2.35, (48, 2) = 0.28741334410836633e-4, (49, 1) = 2.4, (49, 2) = -0.2423552947809686e-4, (50, 1) = 2.45, (50, 2) = 0.20115974495047912e-4, (51, 1) = 2.5, (51, 2) = -0.16360968960468515e-4, (52, 1) = 2.55, (52, 2) = 0.12948742231058999e-4, (53, 1) = 2.6, (53, 2) = -0.985774731176686e-5, (54, 1) = 2.65, (54, 2) = 0.706688518346671e-5, (55, 1) = 2.7, (55, 2) = -0.4555672725651303e-5, (56, 1) = 2.75, (56, 2) = 0.23043650036730538e-5, (57, 1) = 2.8, (57, 2) = -0.29404079279315267e-6, (58, 1) = 2.85, (58, 2) = -0.14933413612624144e-5, (59, 1) = 2.9, (59, 2) = 0.30749105483557417e-5, (60, 1) = 2.95, (60, 2) = -0.4466869448461453e-5, (61, 1) = 3.0, (61, 2) = 0.5684494809229467e-5, (62, 1) = 3.05, (62, 2) = -0.67421491593684444e-5, (63, 1) = 3.1, (63, 2) = 0.765330108066053e-5, (64, 1) = 3.15, (64, 2) = -0.8430551865031369e-5, (65, 1) = 3.2, (65, 2) = 0.9085666798487518e-5, (66, 1) = 3.25, (66, 2) = -0.9629609655930039e-5, (67, 1) = 3.3, (67, 2) = 0.10072579272402201e-4, (68, 1) = 3.35, (68, 2) = -0.1042404728762369e-4, (69, 1) = 3.4, (69, 2) = 0.1069279635035891e-4, (70, 1) = 3.45, (70, 2) = -0.10886958224421352e-4, (71, 1) = 3.5, (71, 2) = 0.11014051364892259e-4, (72, 1) = 3.55, (72, 2) = -0.11081017636391213e-4, (73, 1) = 3.6, (73, 2) = 0.11094257929051255e-4, (74, 1) = 3.65, (74, 2) = -0.11059666495657345e-4, (75, 1) = 3.7, (75, 2) = 0.109826638880031e-4, (76, 1) = 3.75, (76, 2) = -0.10868228414258878e-4, (77, 1) = 3.8, (77, 2) = 0.10720926073958364e-4, (78, 1) = 3.85, (78, 2) = -0.1054493895470911e-4, (79, 1) = 3.9, (79, 2) = 0.1034409209623252e-4, (80, 1) = 3.95, (80, 2) = -0.10121878843963985e-4, (81, 1) = 4.0, (81, 2) = 0.9881484727059153e-5, (82, 1) = 4.05, (82, 2) = -0.9625809905064345e-5, (83, 1) = 4.1, (83, 2) = 0.9357490234275213e-5, (84, 1) = 4.15, (84, 2) = -0.9078917009490728e-5, (85, 1) = 4.2, (85, 2) = 0.87922554398473e-5, (86, 1) = 4.25, (86, 2) = -0.8499461919063325e-5, (87, 1) = 4.3, (87, 2) = 0.8202300151001906e-5, (88, 1) = 4.35, (88, 2) = -0.7902356191213331e-5, (89, 1) = 4.4, (89, 2) = 0.7601052464222056e-5, (90, 1) = 4.45, (90, 2) = -0.72996608149495766e-5, (91, 1) = 4.5, (91, 2) = 0.699931465092186e-5, (92, 1) = 4.55, (92, 2) = -0.6701020229904285e-5, (93, 1) = 4.6, (93, 2) = 0.6405667145430395e-5, (94, 1) = 4.65, (94, 2) = -0.6114038060383664e-5, (95, 1) = 4.7, (95, 2) = 0.5826817736440689e-5, (96, 1) = 4.75, (96, 2) = -0.5544601404792595e-5, (97, 1) = 4.8, (97, 2) = 0.52679025211894145e-5, (98, 1) = 4.85, (98, 2) = -0.4997159946020307e-5, (99, 1) = 4.9, (99, 2) = 0.47327445878452e-5, (100, 1) = 4.95, (100, 2) = -0.4474965546586055e-5, (101, 1) = 5.0, (101, 2) = 0.4224075790442743e-5, (102, 1) = 5.05, (102, 2) = -0.3980277398539528e-5, (103, 1) = 5.1, (103, 2) = 0.3743726399348483e-5, (104, 1) = 5.15, (104, 2) = -0.35145372330544755e-5, (105, 1) = 5.2, (105, 2) = 0.3292786864253045e-5, (106, 1) = 5.25, (106, 2) = -0.3078518569671755e-5, (107, 1) = 5.3, (107, 2) = 0.28717454240173786e-5, (108, 1) = 5.35, (108, 2) = -0.2672453505531053e-5, (109, 1) = 5.4, (109, 2) = 0.2480604841418905e-5, (110, 1) = 5.45, (110, 2) = -0.22961401119743008e-5, (111, 1) = 5.5, (111, 2) = 0.21189811309571416e-5, (112, 1) = 5.55, (112, 2) = -0.19490331186010634e-5, (113, 1) = 5.6, (113, 2) = 0.17861867825155937e-5, (114, 1) = 5.65, (114, 2) = -0.16303202207033257e-5, (115, 1) = 5.7, (115, 2) = 0.14813006599365237e-5, (116, 1) = 5.75, (116, 2) = -0.13389860418240196e-5, (117, 1) = 5.8, (117, 2) = 0.12032264680435905e-5, (118, 1) = 5.85, (118, 2) = -0.10738655154134225e-5, (119, 1) = 5.9, (119, 2) = 0.9507414307327055e-6, (120, 1) = 5.95, (120, 2) = -0.8336882146176523e-6, (121, 1) = 6.0, (121, 2) = 0.7225366029120385e-6, (122, 1) = 6.05, (122, 2) = -0.6171149536407717e-6, (123, 1) = 6.1, (123, 2) = 0.5172500469062582e-6, (124, 1) = 6.15, (124, 2) = -0.422767804599377e-6, (125, 1) = 6.2, (125, 2) = 0.3334939363034557e-6, (126, 1) = 6.25, (126, 2) = -0.24925451730719557e-6, (127, 1) = 6.3, (127, 2) = 0.1698765042164462e-6, (128, 1) = 6.35, (128, 2) = -0.9518819325289293e-7, (129, 1) = 6.4, (129, 2) = 0.25019625957658297e-7, (130, 1) = 6.45, (130, 2) = 0.4079705332935711e-7, (131, 1) = 6.5, (131, 2) = -0.10242728416703212e-6, (132, 1) = 6.55, (132, 2) = 0.16003381713738053e-6, (133, 1) = 6.6, (133, 2) = -0.21377647792892648e-6, (134, 1) = 6.65, (134, 2) = 0.2638119651684455e-6, (135, 1) = 6.7, (135, 2) = -0.31029367903289395e-6, (136, 1) = 6.75, (136, 2) = 0.3533715778983202e-6, (137, 1) = 6.8, (137, 2) = -0.3931920604894687e-6, (138, 1) = 6.85, (138, 2) = 0.4298978711906126e-6, (139, 1) = 6.9, (139, 2) = -0.4636280263535863e-6, (140, 1) = 6.95, (140, 2) = 0.494517759612214e-6, (141, 1) = 7.0, (141, 2) = -0.5226984843620009e-6, (142, 1) = 7.05, (142, 2) = 0.5482977717131691e-6, (143, 1) = 7.1, (143, 2) = -0.5714393423533197e-6, (144, 1) = 7.15, (144, 2) = 0.5922430708876365e-6, (145, 1) = 7.2, (145, 2) = -0.610825001331253e-6, (146, 1) = 7.25, (146, 2) = 0.6272973725430698e-6, (147, 1) = 7.3, (147, 2) = -0.641768652482882e-6, (148, 1) = 7.35, (148, 2) = 0.6543435802710991e-6, (149, 1) = 7.4, (149, 2) = -0.6651232151103739e-6, (150, 1) = 7.45, (150, 2) = 0.6742049912106031e-6, (151, 1) = 7.5, (151, 2) = -0.6816827779311618e-6, (152, 1) = 7.55, (152, 2) = 0.6876469444194619e-6, (153, 1) = 7.6, (153, 2) = -0.6921844280904861e-6, (154, 1) = 7.65, (154, 2) = 0.6953788063481056e-6, (155, 1) = 7.7, (155, 2) = -0.6973103710014924e-6, (156, 1) = 7.75, (156, 2) = 0.6980562048815929e-6, (157, 1) = 7.8, (157, 2) = -0.6976902602061175e-6, (158, 1) = 7.85, (158, 2) = 0.6962834382846133e-6, (159, 1) = 7.9, (159, 2) = -0.6939036701932665e-6, (160, 1) = 7.95, (160, 2) = 0.690615998086224e-6, (161, 1) = 8.0, (161, 2) = -0.6864826568410622e-6, (162, 1) = 8.05, (162, 2) = 0.6815631557688252e-6, (163, 1) = 8.1, (163, 2) = -0.6759143601450263e-6, (164, 1) = 8.15, (164, 2) = 0.669590572344911e-6, (165, 1) = 8.2, (165, 2) = -0.6626436123890619e-6, (166, 1) = 8.25, (166, 2) = 0.6551228977290213e-6, (167, 1) = 8.3, (167, 2) = -0.647075522119317e-6, (168, 1) = 8.35, (168, 2) = 0.6385463334437125e-6, (169, 1) = 8.4, (169, 2) = -0.629578010378859e-6, (170, 1) = 8.45, (170, 2) = 0.6202111377936157e-6, (171, 1) = 8.5, (171, 2) = -0.6104842807971703e-6, (172, 1) = 8.55, (172, 2) = 0.6004340573606388e-6, (173, 1) = 8.6, (173, 2) = -0.5900952094508935e-6, (174, 1) = 8.65, (174, 2) = 0.5795006726227363e-6, (175, 1) = 8.7, (175, 2) = -0.5686816440282655e-6, (176, 1) = 8.75, (176, 2) = 0.5576676488088356e-6, (177, 1) = 8.8, (177, 2) = -0.5464866048451384e-6, (178, 1) = 8.85, (178, 2) = 0.5351648858455677e-6, (179, 1) = 8.9, (179, 2) = -0.5237273827621483e-6, (180, 1) = 8.95, (180, 2) = 0.5121975635274654e-6, (181, 1) = 9.0, (181, 2) = -0.5005975311119593e-6, (182, 1) = 9.05, (182, 2) = 0.488948079906314e-6, (183, 1) = 9.1, (183, 2) = -0.4772687504359755e-6, (184, 1) = 9.15, (184, 2) = 0.46557788242095225e-6, (185, 1) = 9.2, (185, 2) = -0.45389266619653036e-6, (186, 1) = 9.25, (186, 2) = 0.4422291925122823e-6, (187, 1) = 9.3, (187, 2) = -0.43060250073186364e-6, (188, 1) = 9.35, (188, 2) = 0.4190266254556287e-6, (189, 1) = 9.4, (189, 2) = -0.4075146415927183e-6, (190, 1) = 9.45, (190, 2) = 0.39607870790862633e-6, (191, 1) = 9.5, (191, 2) = -0.38473010907775763e-6, (192, 1) = 9.55, (192, 2) = 0.37347929627010353e-6, (193, 1) = 9.6, (193, 2) = -0.362335926303425e-6, (194, 1) = 9.65, (194, 2) = 0.35130889939221703e-6, (195, 1) = 9.7, (195, 2) = -0.34040639552618525e-6, (196, 1) = 9.75, (196, 2) = 0.3296359095107469e-6, (197, 1) = 9.8, (197, 2) = -0.3190042847032402e-6, (198, 1) = 9.85, (198, 2) = 0.30851774547799635e-6, (199, 1) = 9.9, (199, 2) = -0.29818192845446557e-6, (200, 1) = 9.95, (200, 2) = 0.2880019125209349e-6, (201, 1) = 10.0, (201, 2) = -0.2779822476886622e-6}, datatype = float[8], order = C_order)

(5)

 

 

 

 


 

Download heat_equation_(2).mw

Hello everyone.

Please can I meet with Computational or/and Numerical anlysts that have worked or working on the algorihms particularly (Runge Kutta Nystrom, Block multistep methods including hybrid and Block Boundaru Value methods) for the solution of both IVP and BVP.

I will appreciante if I can learn from them and possibly collaborate with them. Thank you in anticipation of your positive response.

How to write a code find fundamental matrix of the following Matrix?

restart; with(LinearAlgebra): A:=Matrix([[0, 1, 0, 0], [-a, 0, b, 0], [0, 0, 0, 1], [c, 0, -d, 0]]);eigenvectors(A);

where a,b,c,d∈IR.

I want to find eigenvalues and eigenvectors and then want to calculate e^( λ i)*ri  where λi's are eigenvalues, ri's are eigenvectors of A for i=1,2,3,4  respectively.

Then, I want to calculate Wronskian of the matrix which consists of vectors e^(λi)*ri in the columns. Could you help me?

See: Fundamental Matrix

Find and classify all the critical point(s) for 

f(x,y)=x3 + 3xy2 - 15x + y3 - 15y .

updated

after refer from

https://en.wikipedia.org/wiki/List_of_representations_of_e

exponential1 := sum((1/n!), n=0..infinity);
exponential1 is not a decimal number, it is exp(1)
 
hoyeung1:= sum((Int(exp(LambertW(1/(-1+x))*(-1+x)), x)), x=0..infinity);
 
hoyeung2:= sum((Int(exp(LambertW(1/(-1+x!))*(-1+x!)), x)), x=0..infinity);
 
how to evalute hoyeung1 or hoyeung2 as a decimal number?
 
how to evalute hoyeung^x as a decimal number function is func1 := proc(x) return hoyeung^x end proc:
 
but i do not know whether sum((Int(exp(LambertW(1/(-1+x))*(-1+x)), x))*m^x, x=0..infinity) = hoyeung^x
 
can limit(1+(Int(exp(LambertW(1/(-1+x))*(-1+x)), x)))^x, x=infinity) = hoyeung^1 ?

I need a help from someone who knows the GRTensor commands.

If you create a tensor of rank 2 using the grdef ("F {(a) (b)}"). Until then, okay!

However, I would like to define each of the 16 tensor components and I do not know how to do.

Could someone help me?

Thank you very much!

sol := dsolve(diff(ln(y(x)),x) = y(x)^(1/(1-y(x))), y(x));
x-Intat(_a^(-(-2+_a)/(-1+_a)), _a = y(x))+_C1 = 0
 

the solution is not y(x) = , but y(x) at the right hand side

Lee := (-1+Int(exp(LambertW(1/(-1+t))*(-1+t)), t=1..x))/(Int(exp(LambertW(1/(-1+t))*(-1+t)), t=1..x));
sum(unknown, n=1..infinity) = Lee
 
how to find unknown?
complexpoint run a long time
there is no option numpoints in complexplot, how to fasten it?
 
Lee := (-1+Int(exp(LambertW(1/(-1+t))*(-1+t)), t=1..x))/(Int(exp(LambertW(1/(-1+t))*(-1+t)), t=1..x));
complexplot(Lee, x = 0 .. 1);
Lee := Re(-1+Int(exp(LambertW(1/(-1+t))*(-1+t)), t=1..x))/(Int(exp(LambertW(1/(-1+t))*(-1+t)), t=1..x));
plot(Lee, x = 0 .. 2, numpoints = 5);
Lee := Im(-1+Int(exp(LambertW(1/(-1+t))*(-1+t)), t=1..x))/(Int(exp(LambertW(1/(-1+t))*(-1+t)), t=1..x));
plot(Lee, x = 0 .. 2, numpoints = 5);
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