Maple Questions and Posts

These are Posts and Questions associated with the product, Maple

In this work the theme of vector analysis shown from a computational point of view; this being a very important role in the engineering component; in civil and mechanical special it is why, using the scientific software Maple develops interactive solutions for long processes through MapleCloud calculations. At present the majority of professors / researchers perform static classes open source leaves; so that our students learn and memorize commands, thus generating more time learning in the area. Loading Bookseller VectorCalculus develop topics: vector algebra, differential operators, conservative fields, etc. Maplesoft making processes provide immediate calculations long operation Embedded Components displayed in line with MapleNet integrations. Today our future engineers to design solutions and will be launched in the cloud thus being a process with global qualification in the specialty. Significantly Maple is a scientific software which allows the researcher to design their own innovations and not use themes for their manufacturers.

 

III_CRF_2015.pdf

CRF_2015.mw

 

L.AraujoC.

 

 

I have some excel data which I need to fit in the formula:

0.5a*erfc(0.5*2^0.5*(-x+m1/s1)) + (0.5-0.5a)*erfc(0.5*2^0.5*(-x+m2/s2))

In this formula the coefficient m ans s are mean and standard deviation and a is the weigth of 2 peak in a cummulative gaussian distribution.

I fitted this (I will insert the maple file) and found:

-48736.43 erfc(-0.707x + 0.707) + 48736.43 erfc(0.707x + 0.707)

Can this be correct?

And how do I find the values of m1, s1, m2, s2 and a?

data.xlsx

data_fit.mw

I want to solve numerically the nonlinear pde:

 

u_x+u_t - (u_{xt})^2 = u(x,t)

 

which method do you propose me to use with maple? (I don't mine about which boundary conditions to be used here).

 

Hello.
Have a question for use Physics[TransformCoordinates] . For example, in a Cartesian coordinate system is an arbitrary tensor. As you know, in this case the covariant, contravariant and mixed components are the same. We have a coordinate transformation such as transforming our Cartesian coordinate system in the oblique coordinate system. In this simple example, correctly calculated the covariant, contravariant and mixed components (structure: covariant and contravariant), but other mixed components (structure: contravariant and covariant) are calculated is not correct. I checked by hand.



restart

with(Physics):

Setup(mathematicalnotation = true):

ds := dx[1]^2+dx[2]^2+dx[3]^2:

Setup(coordinates = (X = [x[1], x[2], x[3]]), dimension = 3, metric = ds, spacetimeindices = lowercaselatin, quiet):

g_[]:

A[a, b] = Matrix(3, 3, {(1, 1) = 2, (1, 2) = 1, (1, 3) = 3, (2, 1) = 2, (2, 2) = 3, (2, 3) = 4, (3, 1) = 1, (3, 2) = 2, (3, 3) = 1})

A[a, b] = (Matrix(3, 3, {(1, 1) = 2, (1, 2) = 1, (1, 3) = 3, (2, 1) = 2, (2, 2) = 3, (2, 3) = 4, (3, 1) = 1, (3, 2) = 2, (3, 3) = 1}))

(1)

Define(%):

`Defined objects with tensor properties`

(2)

A[]

A[a, b] = (Matrix(3, 3, {(1, 1) = 2, (1, 2) = 1, (1, 3) = 3, (2, 1) = 2, (2, 2) = 3, (2, 3) = 4, (3, 1) = 1, (3, 2) = 2, (3, 3) = 1}))

(3)

A[`~`]

A[`~a`, `~b`] = (Matrix(3, 3, {(1, 1) = 2, (1, 2) = 1, (1, 3) = 3, (2, 1) = 2, (2, 2) = 3, (2, 3) = 4, (3, 1) = 1, (3, 2) = 2, (3, 3) = 1}))

(4)

A[`~a`,b,matrix]

A[`~a`, b] = (Matrix(3, 3, {(1, 1) = 2, (1, 2) = 1, (1, 3) = 3, (2, 1) = 2, (2, 2) = 3, (2, 3) = 4, (3, 1) = 1, (3, 2) = 2, (3, 3) = 1}))

(5)

A[`a`,~b,matrix]

A[a, `~b`] = (Matrix(3, 3, {(1, 1) = 2, (1, 2) = 1, (1, 3) = 3, (2, 1) = 2, (2, 2) = 3, (2, 3) = 4, (3, 1) = 1, (3, 2) = 2, (3, 3) = 1}))

(6)

[y[1] = x[1]-x[2], y[2] = x[2]-x[3], y[3] = x[3]]

[y[1] = x[1]-x[2], y[2] = x[2]-x[3], y[3] = x[3]]

(7)

solve((7), {x[1], x[2], x[3]})

{x[1] = y[1]+y[2]+y[3], x[2] = y[2]+y[3], x[3] = y[3]}

(8)

OK

B[a,b] = TransformCoordinates((8), A[a, b], [y[1], y[2], y[3]], [x[1], x[2], x[3]], simplifier = `@`(`simplify/size`, simplify))

B[a, b] = (Matrix(3, 3, {(1, 1) = 2, (1, 2) = 3, (1, 3) = 6, (2, 1) = 4, (2, 2) = 8, (2, 3) = 15, (3, 1) = 5, (3, 2) = 11, (3, 3) = 19}))

(9)

OK

C[a,b] = TransformCoordinates((8), A[~a,~b], [y[1], y[2], y[3]], [x[1], x[2], x[3]], simplifier = `@`(`simplify/size`, simplify))

C[a, b] = (Matrix(3, 3, {(1, 1) = 2, (1, 2) = -1, (1, 3) = -1, (2, 1) = 0, (2, 2) = -2, (2, 3) = 3, (3, 1) = -1, (3, 2) = 1, (3, 3) = 1}))

(10)

OK

D[a,b] = TransformCoordinates((8), A[a,~b], [y[1], y[2], y[3]], [x[1], x[2], x[3]], simplifier = `@`(`simplify/size`, simplify))NULL

D[a, b] = Matrix(%id = 4452149890)

(11)

Bug

E[a, b] = TransformCoordinates((8), A[~a,b], [y[1], y[2], y[3]], [x[1], x[2], x[3]], simplifier = `@`(`simplify/size`, simplify))NULLNULL

E[a, b] = Matrix(%id = 4452139458)

(12)

should be

LinearAlgebra:-Transpose(rhs((12)))

Matrix(3, 3, {(1, 1) = 0, (1, 2) = -2, (1, 3) = -3, (2, 1) = 1, (2, 2) = 2, (2, 3) = 5, (3, 1) = 1, (3, 2) = 3, (3, 3) = 4})

(13)

``



Download Transformation_tensor_components.mw

I recently got myself a 64 bit computer and have noticed that I cannot use the option compile=true in dsolve/numeric. Take the following simple example:

dsolve({diff(x(t),t)=x(t),x(0)=1},numeric,compile=true);
Error, (in dsolve/numeric/SC/preproc) unable to compile (rc=1), please try again, and if that fails verify your Windows compiler installation

I'm using Windows 10, but had the same problem with Windows 8.1 on the same machine.
The Compiler:-Compile examples in the help page all work.

What do I have to do to make the option compile=true work in dsolve/numeric?

You may safely assume that I don't know any technicalities about these things.

hi, I am tyying to solve this equation but there is arising an error, plz help me,
VIM.3rd_order.mw

How to change the font style, globally, the inputs and outputs of computations in Maple 2015? That is, every time a new document is started, the chosen style is automatically applied.

Oliveira.

This Question involves using dsolve(..., numeric) for an IVP specifed by a procedure. This is based on a Question asked earlier today. In this Question, I have no interest in how to solve this IVP or in why this solution technique fails. In the worksheet below, the odeplot command seems to get stuck in an infinite loop (I am not interested in why that happens), and I press the stop button (in the Standard GUI). Then, instead of the usual Warning, computation interupted message followed by a return to the command prompt, I get an informative message and the plot that has been computed so far. This seems like a very useful feature: to return the results computed so far after an interuption. Furthermore, those results are programmatically accessible. My Question is How is this done? How do you trap the stop button and return the results?


restart:


Sys:= proc(N,t,Y,YP)

local eqs,yp2,yp4;

     YP[1]:= Y[2];

     YP[3]:= Y[4];

     eqs:= [
          yp2*Y[3]+yp4*Y[2]*sin(Y[1]^2)+cos(yp4*Y[3]) = sin(t),
          Y[2]*yp4*sin(Y[1]*Y[3])+5*yp2*Y[4]*cos(Y[1]^2)+t^2*Y[1]*Y[3]^2 = exp(-Y[3]^2)
     ];

     YP[2],YP[4]:= op(subs(fsolve(eqs,{yp2=1,yp4=2}),[yp2,yp4]))

end proc:

res:= dsolve(
     numeric, procedure= Sys, initial= Array([1,1,2,2]),
     number= 4, procvars= [x1(t),diff(x1(t),t),x2(t),diff(x2(t),t)],
     start= 0, maxfun= 0
):

 

plots:-odeplot(res, [t,x1(t)], 0..0.27);
#After 10 seconds or so, (I did)/(you should) hit the stop button.

Warning, cannot evaluate the solution further right of .25109286, cannot downgrade delay storage for problems with delay derivative order > 1, try increasing delaypts

#Note that the command's result is still programmatically accessible:

P:= %;

PLOT(CURVES(Array(1..201, 1..2, {(1, 1) = .0, (1, 2) = 1.0, (2, 1) = 0.135e-2, (2, 2) = 1.001349729199153, (3, 1) = 0.27e-2, (3, 2) = 1.0026989169868508, (4, 1) = 0.405e-2, (4, 2) = 1.004047563645964, (5, 1) = 0.54e-2, (5, 2) = 1.005395669456049, (6, 1) = 0.675e-2, (6, 2) = 1.0067432346933451, (7, 1) = 0.81e-2, (7, 2) = 1.0080902596307788, (8, 1) = 0.945e-2, (8, 2) = 1.0094367445379593, (9, 1) = 0.108e-1, (9, 2) = 1.0107826896811836, (10, 1) = 0.1215e-1, (10, 2) = 1.01212809532343, (11, 1) = 0.135e-1, (11, 2) = 1.0134729617243639, (12, 1) = 0.1485e-1, (12, 2) = 1.0148172891403349, (13, 1) = 0.162e-1, (13, 2) = 1.0161610778243784, (14, 1) = 0.1755e-1, (14, 2) = 1.0175043280262126, (15, 1) = 0.189e-1, (15, 2) = 1.0188470399922427, (16, 1) = 0.2025e-1, (16, 2) = 1.020189213965557, (17, 1) = 0.216e-1, (17, 2) = 1.0215308501859302, (18, 1) = 0.2295e-1, (18, 2) = 1.0228719488898206, (19, 1) = 0.243e-1, (19, 2) = 1.0242125103103719, (20, 1) = 0.2565e-1, (20, 2) = 1.0255525346774133, (21, 1) = 0.27e-1, (21, 2) = 1.0268920222174571, (22, 1) = 0.2835e-1, (22, 2) = 1.0282309731537027, (23, 1) = 0.297e-1, (23, 2) = 1.0295693877060321, (24, 1) = 0.3105e-1, (24, 2) = 1.0309072660910137, (25, 1) = 0.324e-1, (25, 2) = 1.0322446085219004, (26, 1) = 0.3375e-1, (26, 2) = 1.0335814152086296, (27, 1) = 0.351e-1, (27, 2) = 1.0349176863578238, (28, 1) = 0.3645e-1, (28, 2) = 1.0362534221727904, (29, 1) = 0.378e-1, (29, 2) = 1.037588622853522, (30, 1) = 0.3915e-1, (30, 2) = 1.0389232885966946, (31, 1) = 0.405e-1, (31, 2) = 1.0402574195956709, (32, 1) = 0.4185e-1, (32, 2) = 1.041591016040497, (33, 1) = 0.432e-1, (33, 2) = 1.0429240781179057, (34, 1) = 0.4455e-1, (34, 2) = 1.044256606011312, (35, 1) = 0.459e-1, (35, 2) = 1.0455885999008183, (36, 1) = 0.4725e-1, (36, 2) = 1.04692005996321, (37, 1) = 0.486e-1, (37, 2) = 1.0482509863719582, (38, 1) = 0.4995e-1, (38, 2) = 1.0495813792972193, (39, 1) = 0.513e-1, (39, 2) = 1.0509112389058335, (40, 1) = 0.5265e-1, (40, 2) = 1.0522405653613263, (41, 1) = 0.54e-1, (41, 2) = 1.0535693587831985, (42, 1) = 0.5535e-1, (42, 2) = 1.0548976192244952, (43, 1) = 0.567e-1, (43, 2) = 1.0562253468268996, (44, 1) = 0.5805e-1, (44, 2) = 1.0575525417260814, (45, 1) = 0.594e-1, (45, 2) = 1.058879204046671, (46, 1) = 0.6075e-1, (46, 2) = 1.0602053339022601, (47, 1) = 0.621e-1, (47, 2) = 1.0615309313954047, (48, 1) = 0.6345e-1, (48, 2) = 1.0628559966176196, (49, 1) = 0.648e-1, (49, 2) = 1.0641805296493847, (50, 1) = 0.6615e-1, (50, 2) = 1.0655045305601394, (51, 1) = 0.675e-1, (51, 2) = 1.0668279994082868, (52, 1) = 0.6885e-1, (52, 2) = 1.06815093624119, (53, 1) = 0.702e-1, (53, 2) = 1.0694733410951756, (54, 1) = 0.7155e-1, (54, 2) = 1.0707952139955317, (55, 1) = 0.729e-1, (55, 2) = 1.0721165549565084, (56, 1) = 0.7425e-1, (56, 2) = 1.0734373639813168, (57, 1) = 0.756e-1, (57, 2) = 1.074757641062132, (58, 1) = 0.7695e-1, (58, 2) = 1.0760773861800887, (59, 1) = 0.783e-1, (59, 2) = 1.0773965993052852, (60, 1) = 0.7965e-1, (60, 2) = 1.078715280396781, (61, 1) = 0.81e-1, (61, 2) = 1.0800334294025973, (62, 1) = 0.8235e-1, (62, 2) = 1.081351046259718, (63, 1) = 0.837e-1, (63, 2) = 1.082668130894088, (64, 1) = 0.8505e-1, (64, 2) = 1.0839846832206155, (65, 1) = 0.864e-1, (65, 2) = 1.0853007031431687, (66, 1) = 0.8775e-1, (66, 2) = 1.08661619055458, (67, 1) = 0.891e-1, (67, 2) = 1.0879311453366416, (68, 1) = 0.9045e-1, (68, 2) = 1.0892455673601087, (69, 1) = 0.918e-1, (69, 2) = 1.0905594564846983, (70, 1) = 0.9315e-1, (70, 2) = 1.0918728125590897, (71, 1) = 0.945e-1, (71, 2) = 1.0931856354209235, (72, 1) = 0.9585e-1, (72, 2) = 1.0944979248968028, (73, 1) = 0.972e-1, (73, 2) = 1.0958096808022917, (74, 1) = 0.9855e-1, (74, 2) = 1.097120902941917, (75, 1) = 0.999e-1, (75, 2) = 1.098431591109168, (76, 1) = .10125, (76, 2) = 1.0997417450864941, (77, 1) = .1026, (77, 2) = 1.1010513646453082, (78, 1) = .10395, (78, 2) = 1.1023604495459853, (79, 1) = .1053, (79, 2) = 1.1036689995378606, (80, 1) = .10665, (80, 2) = 1.1049770143592332, (81, 1) = .108, (81, 2) = 1.1062844937176912, (82, 1) = .10935, (82, 2) = 1.1075914369810387, (83, 1) = .1107, (83, 2) = 1.108897843678326, (84, 1) = .11205, (84, 2) = 1.1102037134210607, (85, 1) = .1134, (85, 2) = 1.1115090457860155, (86, 1) = .11475, (86, 2) = 1.1128138403152263, (87, 1) = .1161, (87, 2) = 1.1141180965159976, (88, 1) = .11745, (88, 2) = 1.1154218138608973, (89, 1) = .1188, (89, 2) = 1.1167249917877577, (90, 1) = .12015, (90, 2) = 1.118027629699678, (91, 1) = .1215, (91, 2) = 1.1193297269650222, (92, 1) = .12285, (92, 2) = 1.1206312829174188, (93, 1) = .1242, (93, 2) = 1.1219322968557623, (94, 1) = .12555, (94, 2) = 1.123232768044212, (95, 1) = .1269, (95, 2) = 1.1245326957121933, (96, 1) = .12825, (96, 2) = 1.1258320790543948, (97, 1) = .1296, (97, 2) = 1.1271309172307735, (98, 1) = .13095, (98, 2) = 1.1284292093665487, (99, 1) = .1323, (99, 2) = 1.1297269545522062, (100, 1) = .13365, (100, 2) = 1.131024151843497, (101, 1) = .135, (101, 2) = 1.1323208002614376, (102, 1) = .13635, (102, 2) = 1.133616898792309, (103, 1) = .1377, (103, 2) = 1.1349124463876585, (104, 1) = .13905, (104, 2) = 1.1362074419642976, (105, 1) = .1404, (105, 2) = 1.137501884404303, (106, 1) = .14175, (106, 2) = 1.1387957725550182, (107, 1) = .1431, (107, 2) = 1.1400891052290492, (108, 1) = .14445, (108, 2) = 1.1413818812042709, (109, 1) = .1458, (109, 2) = 1.1426740992238196, (110, 1) = .14715, (110, 2) = 1.1439657579960996, (111, 1) = .1485, (111, 2) = 1.1452568561947796, (112, 1) = .14985, (112, 2) = 1.1465473922561644, (113, 1) = .1512, (113, 2) = 1.1478373642224777, (114, 1) = .15255, (114, 2) = 1.14912677047606, (115, 1) = .1539, (115, 2) = 1.1504156093257876, (116, 1) = .15525, (116, 2) = 1.1517038789853584, (117, 1) = .1566, (117, 2) = 1.1529915775732906, (118, 1) = .15795, (118, 2) = 1.1542787031129238, (119, 1) = .1593, (119, 2) = 1.1555652535324183, (120, 1) = .16065, (120, 2) = 1.1568512266647548, (121, 1) = .162, (121, 2) = 1.1581366202477354, (122, 1) = .16335, (122, 2) = 1.1594214319239837, (123, 1) = .1647, (123, 2) = 1.1607056592409424, (124, 1) = .16605, (124, 2) = 1.1619892996508772, (125, 1) = .1674, (125, 2) = 1.1632723505108726, (126, 1) = .16875, (126, 2) = 1.1645548090828357, (127, 1) = .1701, (127, 2) = 1.165836672533493, (128, 1) = .17145, (128, 2) = 1.1671179379343934, (129, 1) = .1728, (129, 2) = 1.1683986022619053, (130, 1) = .17415, (130, 2) = 1.169678662397219, (131, 1) = .1755, (131, 2) = 1.1709581151263448, (132, 1) = .17685, (132, 2) = 1.172236957140115, (133, 1) = .1782, (133, 2) = 1.1735151850341814, (134, 1) = .17955, (134, 2) = 1.174792795282732, (135, 1) = .1809, (135, 2) = 1.1760697835893776, (136, 1) = .18225, (136, 2) = 1.1773461457270373, (137, 1) = .1836, (137, 2) = 1.1786218774884782, (138, 1) = .18495, (138, 2) = 1.179896974422449, (139, 1) = .1863, (139, 2) = 1.181171431833682, (140, 1) = .18765, (140, 2) = 1.182445244782893, (141, 1) = .189, (141, 2) = 1.1837184080867809, (142, 1) = .19035, (142, 2) = 1.1849909163180268, (143, 1) = .1917, (143, 2) = 1.1862627638052967, (144, 1) = .19305, (144, 2) = 1.1875339446332376, (145, 1) = .1944, (145, 2) = 1.1888044526424812, (146, 1) = .19575, (146, 2) = 1.1900742814296414, (147, 1) = .1971, (147, 2) = 1.1913434243473158, (148, 1) = .19845, (148, 2) = 1.1926118745040841, (149, 1) = .1998, (149, 2) = 1.193879624764512, (150, 1) = .20115, (150, 2) = 1.195146667749144, (151, 1) = .2025, (151, 2) = 1.1964129956664247, (152, 1) = .20385, (152, 2) = 1.1976785994686407, (153, 1) = .2052, (153, 2) = 1.1989434702227826, (154, 1) = .20655, (154, 2) = 1.2002075985381981, (155, 1) = .2079, (155, 2) = 1.2014709744148189, (156, 1) = .20925, (156, 2) = 1.2027335872431564, (157, 1) = .2106, (157, 2) = 1.2039954258043046, (158, 1) = .21195, (158, 2) = 1.2052564782699382, (159, 1) = .2133, (159, 2) = 1.2065167322023145, (160, 1) = .21465, (160, 2) = 1.2077761745542712, (161, 1) = .216, (161, 2) = 1.2090347916692288, (162, 1) = .21735, (162, 2) = 1.2102925692811892, (163, 1) = .2187, (163, 2) = 1.2115494925044938, (164, 1) = .22005, (164, 2) = 1.2128055446540236, (165, 1) = .2214, (165, 2) = 1.2140607079057624, (166, 1) = .22275, (166, 2) = 1.2153149635677838, (167, 1) = .2241, (167, 2) = 1.216568291442756, (168, 1) = .22545, (168, 2) = 1.2178206698279472, (169, 1) = .2268, (169, 2) = 1.2190720755152231, (170, 1) = .22815, (170, 2) = 1.2203224837910482, (171, 1) = .2295, (171, 2) = 1.221571868436484, (172, 1) = .23085, (172, 2) = 1.22282020172719, (173, 1) = .2322, (173, 2) = 1.224067453329788, (174, 1) = .23355, (174, 2) = 1.225313589366023, (175, 1) = .2349, (175, 2) = 1.226558573530251, (176, 1) = .23625, (176, 2) = 1.227802365810496, (177, 1) = .2376, (177, 2) = 1.229044922475539, (178, 1) = .23895, (178, 2) = 1.2302861960749185, (179, 1) = .2403, (179, 2) = 1.2315261354389295, (180, 1) = .24165, (180, 2) = 1.2327646837576534, (181, 1) = .243, (181, 2) = 1.2340017760538164, (182, 1) = .24435, (182, 2) = 1.2352373405616506, (183, 1) = .2457, (183, 2) = 1.2364712973589982, (184, 1) = .24705, (184, 2) = 1.2377035562942194, (185, 1) = .2484, (185, 2) = 1.2389340149185948, (186, 1) = .24975, (186, 2) = 1.2401625575137232, (187, 1) = .2511, (187, 2) = undefined, (188, 1) = .25245, (188, 2) = undefined, (189, 1) = .2538, (189, 2) = undefined, (190, 1) = .25515, (190, 2) = undefined, (191, 1) = .2565, (191, 2) = undefined, (192, 1) = .25785, (192, 2) = undefined, (193, 1) = .2592, (193, 2) = undefined, (194, 1) = .26055, (194, 2) = undefined, (195, 1) = .2619, (195, 2) = undefined, (196, 1) = .26325, (196, 2) = undefined, (197, 1) = .2646, (197, 2) = undefined, (198, 1) = .26595, (198, 2) = undefined, (199, 1) = .2673, (199, 2) = undefined, (200, 1) = .26865, (200, 2) = undefined, (201, 1) = .27, (201, 2) = undefined}, datatype = float[8], order = C_order), COLOUR(RGB, .47058824, 0., 0.54901961e-1)), AXESLABELS(t, x1))

``


Download trap_stop_button.mw

 

 

restart;
odes:=diff(x1(t),t)*diff(x2(t),t$2)*sin(x1(t)*x2(t))+5*diff(x1(t),t$2)*diff(x2(t),t)*cos(x1(t)^2)+t^2*x1(t)*x2(t)^2=exp(-x2(t)^2),diff(x1(t),t$2)*x2(t)+diff(x2(t),t$2)*diff(x1(t),t)*sin(x1(t)^2)+cos(diff(x2(t),t$2)*x2(t))=sin(t);
ics:=x1(0)=1,D(x1)(0)=1,x2(0)=2,D(x2)(0)=2;
subs(diff(x1(t),t$2)=yp2,diff(x2(t),t$2)=yp4,diff(x1(t),t)=Y[2],diff(x2(t),t)=Y[4],x1(t)=Y[1],x2(t)=Y[3],{odes});
p:=proc(N,t,Y,YP)
local eqs,yp2,yp4;
YP[1]=Y[2];
YP[3]=Y[4];
eqs:=[yp2*Y[3]+yp4*Y[2]*sin(Y[1]^2)+cos(yp4*Y[3]) = sin(t), Y[2]*yp4*sin(Y[1]*Y[3])+5*yp2*Y[4]*cos(Y[1]^2)+t^2*Y[1]*Y[3]^2 = exp(-Y[3]^2)];
YP[2],YP[4]:=op(subs(fsolve(eqs,{yp2=1,yp4=2}),[yp2,yp4]));
end proc:
res:=dsolve(numeric,procedure=p,initial=array([1,1,2,2]),number=4,procvars=[x1(t),diff(x1(t),t),x2(t),diff(x2(t),t)],start=0,maxfun=0);
plots:-odeplot(res,[t,x1(t)],0..5,gridlines=true);

It's a long time to wait for the odeplot.

Any advice is appreciated.

How do I iterate starting from a given value. For example, I want to iterate a function F(x) evalf(solve(F(x)=-38)) so that the next value that F(x) uses is the solution to the previous?

Is there a way to convert this FDTD code into Maple

Hy(1 to M)=0;

Ex(1 to M+1)=0;

For t=1 to T,

Ex(1)=exp(-t);

For k=1 to M,

Hy(k)=Hy(k)-(Ex(k+1)-Ex(k));

end

For k=2 to M,

Ex(k)=Ex(k)-(Hy(k)-Hy(k-1));

end

end

Thanks in advance.

Hello, 

I want to solve and plot a multitime recurrence of the Samuelson Hicks Model (http://www.mathem.pub.ro/proc/bsgp-22/K22-gh-A84.pdf).

Feel free to share any tips that could help.

Thank you. 

hello every one

i need to solve this equation

> A1 := Matrix([[a11, a12, a13], [a12, a22, a23], [a13, a23, a33]]);
> A2 := Matrix([[A], [B], [C]]);
> A3 := Matrix([[15], [0], [0]]);
> eq := multiply(A1, A2)=A3;

> solve(eq, {A, B, C});

thank you :)

Hi, I'm tying to solve the ODE by variational iteration method, programme is running, but maple answer does'nt  match to origional answer, plz tell me the mistake?

ICs y(0)=y'(0)=y''(0)=1

VIM_2.mw

First 1217 1218 1219 1220 1221 1222 1223 Last Page 1219 of 2224