Maple Questions and Posts

These are Posts and Questions associated with the product, Maple


How do I?
I'm very new in Maple, just I wanna learn a lot but i don't know where to start.
I have to find x,y, Tl, Th and Ti

Maybe we can help me at least a litle bit :D
thanks

 

 

I have $ signs suddenly apearing down the side of my document. They are randomly formatting numbers. Don't know how I turned it on. How to undo?  Do they affect calculation accuracy or are they purely dislap formatting

 

 

 

I'm new using maple and I trying to solve this equation:

u*(diff(u*(diff(R(u), u)), u))-(-m^2+u^2+fu)*R(u) = 0

Maple give this solution:

R(u) = _C1*BesselI(sqrt(-m^2+fu), u)+_C2*BesselK(sqrt(-m^2+fu), u)

But I don't know how I can find de constant C1 and C2.

Thanks in advance.

 

I have an equation were build with many unfixed numbers of variables as below:

eq:=f(U[i,j],V[i,j],W[i,j],S[i,j],T[i,j]), i,j=0,1,2,...(changing during the program running)

How do you suggest to calculate the first derivative of such equation with respect to U[i,j],V[i,j],W[i,j],S[i,j],T[i,j]?

Suppose that i,j=22, in this way to calculate the metioned derivative with respect to U[0,0] only, I must write:

diff( eq(U[0,0],U[0,1],U[0,2],...U[22,22], V[0,0],V[0,1],...,T[22,22]), U[0,0])  ( More than 2420 terms)

As you see it needs cumbersome writings if i,j be constants, and because the i and j are changing during the program, I dont know how to cope with this derivatives in Maple??

Here's a little procedure to fish out data from the Simbad database.  Some star names may not work if the page Simbad brings up is not completely filled, but it should work for most queries.


 

restart; gc()

Simbad := proc (a::string) local b, c, c1, c2, c3, c4, c5, d1, d2, d3, d4, d5, e1, e2, e3, e4, e5; b := StringTools:-DeleteSpace(StringTools:-Substitute(a, " ", "+")); c := HTTP:-Get(cat("http://simbad.u-strasbg.fr/simbad/sim-id?Ident=", b, "&submit=submit+id")); c1 := StringTools:-Search("Parallaxes", c[2]); c2 := StringTools:-Search("Radial", c[2]); c3 := StringTools:-Search("Spectral type:", c[2]); c4 := StringTools:-Search("Gal", c[2]); c5 := StringTools:-Search("ICRS", c[2]); d1 := c[2][c1+87 .. c1+93]; d2 := c[2][c2+96 .. c2+110]; d3 := c[2][c3+77 .. c3+90]; d4 := c[2][c4+122 .. c4+140]; d5 := c[2][c5+135 .. c5+164]; e1 := d1[() .. StringTools:-Search(" ", d1)]; e2 := d2[() .. StringTools:-SearchAll(" ", d2)[2]]; e3 := d3[() .. StringTools:-Search(" ", d3)]; e4 := convert(evalf(1000/parse(e1)), 'units', 'parsec', 'ly'); e5 := d5[() .. StringTools:-Search("\n", d5)-1]; print(cat(StringTools:-Capitalize(a), "\nDistance", e4, "lightyears", "\nRight Ascension and declination:", e5, "\nGalactic coordinates", d4, "Spectral Type:", e3, "\nRadial velocity:", e2, "\nParallax", e1, "milliarcseconds")) end proc:
 

Simbad("epsilon eridani")

"Epsilon Eridani
Distance" || (10.48936700) || "lightyears" || "
Right Ascension and declination:" || "03 32 55.84496 -09 27 29.7312" || "
Galactic coordinates" || "195.8446 -48.0513
 " || "Spectral Type:" || "K2Vk: " || "
Radial velocity:" || "V(km/s) 16.43 " || "
Parallax" || "310.94 " || "milliarcseconds"

(1)

Simbad("alpha centauri")

"Alpha Centauri
Distance" || (4.395638513) || "lightyears" || "
Right Ascension and declination:" || "14 39 36.204 -60 50 08.23" || "
Galactic coordinates" || "315.7330 -00.6809
 " || "Spectral Type:" || "G2V+K1V " || "
Radial velocity:" || "V(km/s) -22.3 " || "
Parallax" || "742 " || "milliarcseconds"

(2)

Simbad("beta hydri")

"Beta Hydri
Distance" || (24.32731987) || "lightyears" || "
Right Ascension and declination:" || "00 25 45.07036 -77 15 15.2860" || "
Galactic coordinates" || "304.7720 -39.7821
 " || "Spectral Type:" || "G0V " || "
Radial velocity:" || "V(km/s) 23.10 " || "
Parallax" || "134.07 " || "milliarcseconds"

(3)

Simbad("HR6998")

"Hr6998
Distance" || (42.67386858) || "lightyears" || "
Right Ascension and declination:" || "18 38 53.40045 -21 03 06.7368" || "
Galactic coordinates" || "012.7251 -06.7965
 " || "Spectral Type:" || "G6V " || "
Radial velocity:" || "V(km/s) 36.175 " || "
Parallax" || "76.43 " || "milliarcseconds"

(4)

``


 

Download star_database_-_simbad.mw

What is the total number of the characters in "Vanity Fair" by William Thackeray?
How to determine it with Maple, making use of StringTools and EssayTools? I think an electronic version of this novel is free. 
AFAIK, there are about 600 personages in "And Quiet Flows the Don" by Mikhail Sholokhov.

PS. It happened to me to collaborate with Dr. I. Kulchytskyi on text analysis, but the asked problem is new for me.

PPS. Here is a link to the plain text.

Import("http://www.gutenberg.org/cache/epub/599/pg599.txt");

 

I found this http://www.atlasoftheuniverse.com/50lys.html and wondered how to do it in Maple. With a bit of data file editing I came up with this.  All stars within 50 light years that are visible to the naked eye.


 

restart; gc()

with(plots):

with(plottools):

a := readdata("c:/stars3.txt", [string, float, float, float]):

b := map(proc (a) options operator, arrow; [a[4], a[2], a[3]] end proc, a):

g := :-changecoords([x, y, z], [x, y, z], spherical, [r, theta, (1/2)*Pi-phi])

[r*sin((1/2)*Pi-phi)*cos(theta), r*sin((1/2)*Pi-phi)*sin(theta), r*cos((1/2)*Pi-phi)]

(1)

tt := [seq(evalf(subs({phi = convert(b[i][3]*degrees, radians), r = b[i][1], theta = convert(b[i][2]*degrees, radians)}, g)), i = 1 .. nops(b))]:

stars := pointplot3d(tt, color = red, symbol = solidcircle, symbolsize = 5)

PLOT3D(POINTS([3.141656625, -3.065814279, -0.5363263369e-1], [-5.772842366, -6.234102660, -1.330509322], [-6.747305264, -1.909294949, -7.815271235], [-9.249301903, -6.168517561, 2.566691531], [1.523622092, 11.26895208, -1.155073477], [7.242651534, -3.194389926, -8.791403287], [-3.375068769, .4084281956, -11.40403864], [-12.10139419, -4.596888455, -10.15024015], [14.09808071, 8.106755961, 3.279135277], [11.15052984, 12.25427229, -2.594493178], [-3.419769677, 17.11427532, 7.015900193], [15.04843187, -6.018943313, 10.40502857], [-10.42150660, 16.29565570, -1.726327245], [19.37009401, -.5748909284, 2.345071093], [16.86849035, 1.535152882, -10.13730432], [-3.624453569, -10.40801291, -16.40104276], [14.53624850, -8.460298659, -10.67366976], [-7.231982853, 19.97813208, -1.187881627], [9.620796689, 4.103617543, 19.18392802], [-15.19214319, 4.528974584, -17.36108506], [23.35174623, -3.365038049, .5765994043], [-6.811639233, 11.11558498, -20.54249842], [-13.85405602, 12.08566336, -15.98159795], [10.68989447, -15.38074244, -15.60587447], [-14.13228719, 19.88605992, -3.385259168], [10.27598870, 2.927192384, -22.50208215], [9.961208544, 3.724343264, -22.70260980], [9.143348930, 22.07399698, 8.320326164], [-23.59749508, -4.800964644, -10.27138571], [-5.411799069, 22.54176541, 12.37819224], [4.496828592, -12.62856178, -22.94041979], [-9.282551806, -2.504624702, 25.44407764], [-4.991684031, 4.803604874, 26.40640965], [15.07681588, 19.57764444, 11.83914952], [13.33734565, -14.86471460, 19.35333487], [10.71939792, -13.57311193, -22.05778867], [-27.91856076, -4.172456862, -1.331228297], [27.18654831, -8.676334271, -2.647341036], [-23.15604687, -10.84708496, -13.14156540], [24.14988887, 6.742770129, -14.12821003], [-18.24903039, -19.43324358, -12.03679499], [-19.47836941, -6.366512513, -21.22052411], [1.737082939, 1.648430159, 29.76381731], [-8.166167580, 1.661425568, 28.68397239], [-21.79918531, .6850669983, -20.40938762], [19.48447839, -12.08088844, -19.44250077], [9.550472834, -26.52745875, 10.65373179], [7.061767869, -26.72771859, 14.26858765], [-8.925013073, -.5615142310, 29.80743604], [27.25388910, 6.643782013, 15.16765603], [-20.51315816, 25.24143542, .9653395827], [-6.514439942, 18.29467278, 26.63134657], [7.897693130, -27.90985562, -15.94604661], [-30.24778274, -6.539802137, 13.39182687], [-17.39717901, -3.729632012, -28.80846417], [-27.77451873, 19.73832304, -4.425416699], [-16.72100652, 29.91871832, 7.975859507], [16.27294095, 21.36128840, 22.77346814], [-25.44324866, 19.59393922, -15.24864399], [.1513479143, -17.34275050, 31.03237984], [1.717990984, -16.62465483, -31.43293430], [-3.952184454, -11.22283603, 34.16753707], [13.79744768, 29.99780276, 14.83921382], [-13.23790880, 23.68644879, -24.00672435], [22.42836846, 11.77515669, 25.95817545], [-24.22192093, -3.619990337, 27.00973559], [-28.14737644, 22.63107168, -6.108739192], [12.64368664, 3.411528480, 34.29464625], [10.76859270, .9989721406, 35.37371292], [16.76571480, 7.324760688, 32.87131102], [-2.125303532, -30.39325725, -22.70975559], [26.50575552, 7.450431864, 26.68129662], [4.681906269, 34.62812576, -15.77746051], [21.22229159, 16.34336469, -27.73774271], [8.642995477, -16.39289961, 33.84907047], [4.194125964, -26.48066899, -28.95298045], [29.05143012, -24.81226531, -9.951698266], [-12.02418205, -37.67674179, 3.460082988], [-36.31468346, 14.37800028, 8.301913818], [31.32513775, -24.56204547, -5.240626617], [-11.18258143, 31.40433711, -22.91113229], [-30.95713334, -9.346509576, 24.99311013], [-23.18290754, -32.62151994, 9.092350346], [-26.39556889, 28.60460399, -13.63041355], [-40.27955197, 8.782362586, 1.079537348], [-11.43139039, -7.856576969, -38.95407568], [3.769221962, 22.28497845, 34.93658256], [-4.619258428, 34.61973164, 22.85528894], [-23.40542087, 11.26426836, 32.88997769], [39.51971345, -13.14645885, 5.261489147], [6.069471167, -26.08199826, 32.48539497], [-40.13923071, 12.57887241, 3.384394608], [41.02326573, 9.244992210, -5.014408062], [-29.06950326, -20.65862072, -24.78609025], [-27.49729080, 30.53883527, -15.52814989], [-29.74467917, 7.692497076, 31.48332336], [25.85459060, -9.924647480, -34.69169378], [-13.64550398, 34.99890783, -24.20893992], [30.42203099, 31.61316765, -8.607657127], [-33.27978250, -2.970141446, -29.76905838], [-1.180761099, 27.04387545, -35.92262524], [-21.03852595, 37.95450550, 11.87164852], [-19.67481024, -7.473759355, -40.42995379], [39.79319523, 3.271596183, 22.31470081], [-20.50141444, 1.505529746, 41.05062102], [-.6748395635, 38.66153119, 24.82404273], [-16.85106712, -16.67552070, -39.45541086], [40.49802876, 12.53623404, -18.78641538], [-32.93404980, 18.55738333, 27.16384339], [34.92406817, 25.28080920, 17.94659157], [-6.296985384, 45.37992800, 9.404414370], [22.24424377, 32.85461078, 25.08249928], [39.53312079, -25.57512282, 6.115214927], [-1.588926894, 23.92244252, 41.02855658], [-35.74198886, 5.341675996, 31.19429964], [36.98453431, 14.41966737, -26.57424156], [-46.68814535, -5.898084394, -8.552109953], [35.05110270, 5.991394707, 32.01789951], [36.60612781, 13.32354091, -27.78663643], [13.51762166, -35.96304965, 29.05652877], [-10.38961406, -43.95116043, 17.78996954], [-28.30533977, -7.584392920, 38.74662727], [9.914015961, -13.79681314, -45.68312418], [-9.191698604, 47.28718983, 7.802201960], [21.29072957, 42.51660453, 11.24023016], [-35.75149122, -29.78701952, -15.57013949], [5.493536467, -15.01179385, -46.42496206], [-3.928870403, 39.36220535, 29.27122934], [33.42605444, 36.35056112, -1.638197365], [-17.62503890, -46.15541461, -4.148747474], [44.66028688, -18.77345598, 11.18456642], [45.91393827, -16.62061368, -9.934504171]), SYMBOL(_SOLIDCIRCLE, 5), COLOUR(RGB, 1.00000000, 0., 0.))

(2)

lines := seq(`if`(tt[i][3] > 0, line(tt[i], [tt[i][1], tt[i][2], 0], color = blue), line(tt[i], [tt[i][1], tt[i][2], 0], color = blue, linestyle = dot)), i = 1 .. nops(b)):

c1 := circle([0, 0], 10, color = blue):

c2 := circle([0, 0], 20, color = blue):

c3 := circle([0, 0], 30, color = blue):

c4 := circle([0, 0], 40, color = blue):

c5 := circle([0, 0], 50, color = blue):

l1 := line([-50*cos((1/4)*Pi), -50*sin((1/4)*Pi)], [50*cos((1/4)*Pi), 50*sin((1/4)*Pi)], color = blue):

l2 := line([-50*cos(2*Pi*(1/4)), -50*sin(2*Pi*(1/4))], [50*cos(2*((1/4)*Pi)), 50*sin(2*((1/4)*Pi))], color = blue):

l3 := line([-50*cos(3*((1/4)*Pi)), -50*sin(3*((1/4)*Pi))], [50*cos(3*((1/4)*Pi)), 50*sin(3*((1/4)*Pi))], color = blue):

l4 := line([-50*cos(4*((1/4)*Pi)), -50*sin(4*((1/4)*Pi))], [50*cos(4*((1/4)*Pi)), 50*sin(4*((1/4)*Pi))], color = blue):

t1 := textplot([55, 0, "0"], color = blue):NULL

t2 := textplot([55*cos((1/2)*Pi), 55*sin((1/2)*Pi), "90"], color = blue):

t4 := textplot([55*cos(3*Pi*(1/2)), 55*sin(3*Pi*(1/2)), "270"], color = blue):

t3 := textplot([55*cos(Pi), 55*sin(Pi), "180"], color = blue):

a1 := arrow([60, 0], [80, 0], 1.5, 4, .4, color = blue):

a2 := textplot([95, 5, "Galactic Center"]):

d := display(c1, c2, c3, c4, c5, l1, l2, l3, l4, t1, t2, t3, t4, a1, a2, axes = none, scaling = constrained):

to3d := transform(proc (x, y) options operator, arrow; [x, y, 0] end proc):

display(to3d(d), stars, lines, orientation = [-46, 75])

 

``

``

NULL

NULL

The modified data file and the maple worksheet below

stars3.txt

Download Stars50LY.mw

Hellow.
Is Maple understand the symbol f(i,j), f[i,j], f:=-->(i.j) and f_{i,j}  in the same way or in different way.

How to convert a system of differential equations to a matrix?

can infolevel show this matrix during the process?

Using plottools[line], the option for coords does not work.  It remains in cartesian coordinates regardless of the coords specification.

Dear Maple experts,

I am struggling with a difference between the symbolic and numerical solution of an eigendecomposition of a symmetric positive definite matrix. Numerically the solution seems correct, but the symbolic solution puzzles me. In the symbolic solution the reconstructed matrix is different from the original matrix (although the difference between the original and the reconstructed matrix seems to be related to an unknown scalar multiplier.

restart;
with(LinearAlgebra);
Lambda := Matrix(5, 1, symbol = lambda);
Theta := Matrix(5, 5, shape = diagonal, symbol = theta);
#Ω is the matrix that will be diagonalized.
Omega := MatrixPower(Theta, -1/2) . Lambda . Lambda^%T . MatrixPower(Theta, -1/2);
#Ω is symmetric and in practice always positive definite, but I do not know how to specify the assumption of positivess definiteness in Maple
IsMatrixShape(Omega, symmetric);

# the matrix Omega is very simple and Maple finds a symbolic solution
E, V := Eigenvectors(Omega);

# this will not return the original matrix

simplify(V . DiagonalMatrix(E) . V^%T)

# check this numerically with the following values.

lambda[1, 1] := .9;lambda[2, 1] := .8;lambda[3, 1] := .7;lambda[4, 1] := .85;lambda[5, 1] := .7;
theta[1, 1] := .25;theta[2, 2] := .21;theta[3, 3] := .20;theta[4, 4] := .15;theta[5, 5] := .35;

The dotproduct is not always zero, although I thought that the eigenvectors should be orthogonal.

I know eigenvector solutions may be different because of scalar multiples, but here I am not able to understand the differences between the numerical and symbolic solution.

I probably missed something, but I spend the whole saturday trying to solve this problem, but I can not find it.

I attached both files.

Anyone? Thank in advance,

Harry

eigendecomposition_numeric.mw

eigendecomposition_symbolic.mw

Hello, I'd like to generate some data from an audio file, like get the amplitude and the time, so that I can plot it with x = time and y = amplitude, do you know how to do that ?

restart:
tf:=2:
n:=2:
X[1]:=t->t^2:
A[1]:=diff(X[1](t),t,t):
plot(A[1](t),t=0..tf,labels=["Time t","n times derivative of X[1](t)"]);

I have a code like above. I run it. Then,

in the labels; it was written "n times derivative of X[1](t)"] why not "2 times derivative of X[1](t)"]) ? and why was not the subscript appeared ? I mean that I want to see X1 instead of  X[1]?

Help me please.

Thank you.

 

Hi Maple Community,

I just got my Maple licence and currently I'm going thorugh some basic tutorials in which I've encountered a problem I can't seem to fix:

I'm trying to use the 'LinearSolve' solver as it is shown in the examples on the Maplesoft.com support page:

 

 

But I can't seem to get Maple to display a result like it is shown in the picture above.

Instead Maple displays this:

 

I would be very grateful if someone could tell me what I'm doing wrong.

 

regards, Alex

I want to use the solutuion of a DE as a function, including the possibility to plot it.

I have found out that the following comands work, but I cannot undesrtand why. Is there a simpler way?

Truly, Roberto R. Baldino

sol := dsolve({eq, icon}, i(t));
i := unapply(eval(i(t), sol), t);
plot(i(t), t = 0 .. 20, view = [-1 .. 20, -3 .. 3], gridlines);

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