Maple Questions and Posts

These are Posts and Questions associated with the product, Maple

I have an expression of the form

Expr := n0*C[0] + n1*C[1] + ... + nk*C[k] + n = 0,

where the numbers n0,...,nk and n are known to Maple (after it made some calculations), whereas C[0],...,C[k] are undetermined.

I would like to know the values of all of n0,...,nK and n. For n0,...,nk, I found them with 

coeff(Expr, C[m], 1),

with m in 0,...,k. But I don't know how to get the value of the "independent term" n.

Can someone help me with this?

I have a list of lists made from a combinat and was wondering how to make a new list from it that only contains lists that the elements sum up to 0. 

For example:

L1 := [[1,1,1,1], [1,2,0,0], [0,0,0,0], [1,1,-2,0]];

and I want the result to be 

L2:= [[0,0,0,0], [1,1,-2,0]]

Thank you in advance! I'm new to maple so would appreciate the guidance!

I am studying something about complex numbers. 

What commands are specific to find in Maple for complex numbers ?

  • complexplot()
  • conformal()
  • conformal3d()

It seems that there are a lot of standard calculus statements can be used by adding the word : complex 
Iam using here a package downloaded from Maple website : complex analysis for mathematics and engineering

Got the impression that some modern plot commands for complex numbers are not yet in this book present ..and how about other commands?

an_introduction_to_complex_numbers.mws

Is an analytic solution possible for this problem: find an expression for maximum of power subject to constraints f=0, g=0, h=0? The feasible range is: T1, T2, R, Rthhot, Rthcold, and Z>0.

I know how to solve it using either FindMaximum or Langrage multiplier if I assign numerical values to T1, T2, R, Rthhot, Rthcold, and Z. I'd like to know if it's possible to find an analytic solution if I leave T1, T2, R, Rthhot, Rthcold and Z as parameters

I tried this but it did not work:

f := (X, Y, Rload, Rth, S) -> -(T1 - X)/Rthhot + (X - Y)/Rth + S^2*X*(X - Y)/(R + Rload) + (-1)*0.5*S^2*Rload*(X - Y)^2/(R + Rload)^2;

g := (X, Y, Rload, Rth, S) -> (Y - T2)/Rthcold - (X - Y)/Rth - S^2*Y*(X - Y)/(R + Rload) + (-1)*0.5*S^2*Rload*(X - Y)^2/(R + Rload)^2;

h := (X, Y, Rload, Rth, S) -> S^2*Rth/R - Z;

power := (X, Y, Rload, Rth, S) -> S^2*(X - Y)^2*Rload/(R + Rload)^2;

LagrangeMultipliers(power(X, Y, Rload, Rth, S), [f(X, Y, Rload, Rth, S), g(X, Y, Rload, Rth, S), h(X, Y, Rload, Rth, S)], [X, Y, Rload, Rth, S]);

Hello everybody,

I managed to get to the point that i could start part 2 of the book series of applied Dutch math. 

This paragraph is about Taylor series.

Now i am being asked to find a solution for the taylorseries with a certain x value. That is all fine, Maple can spit it out. But to put in into something that is there with a sum sign in front of it is something else. I have to convert the solution into something that is written with "x to the k-ed, something something". 

Now i did find to solution to a not so complex one. I will add that one on the maple sheet. But there is this one that is really complex, and i cant get my head around how to get to the final solution that makes the sum go and work well. It does have some series to it. But i dont know how to find that one out. Is there some trick to make it work? 

Without further ado:

a.

taylor(1/(3-x), x = 2)

series(1+x-2+(x-2)^2+(x-2)^3+(x-2)^4+(x-2)^5+O((x-2)^6),x = 2,6)

(1)

Sum((x-2)^k, k = 0 .. infinity)

Sum((x-2)^k, k = 0 .. infinity)

(2)

b.

taylor(sqrt(x), x = 1, 16)

series(1+(1/2)*(x-1)-(1/8)*(x-1)^2+(1/16)*(x-1)^3-(5/128)*(x-1)^4+(7/256)*(x-1)^5-(21/1024)*(x-1)^6+(33/2048)*(x-1)^7-(429/32768)*(x-1)^8+(715/65536)*(x-1)^9-(2431/262144)*(x-1)^10+(4199/524288)*(x-1)^11-(29393/4194304)*(x-1)^12+(52003/8388608)*(x-1)^13-(185725/33554432)*(x-1)^14+(334305/67108864)*(x-1)^15+O((x-1)^16),x = 1,16)

(3)

"Sum(((x-1)^(k))/(???????),k=0..infinity)"

8*(1/2); 16*(1/8); 128*(1/16); 256*(1/128); 1024*(1/256); 2048*(1/1024); 32768*(1/2048); 65536*(1/32768); 262144*(1/65536); 524288*(1/262144); 4194304*(1/524288); 8388608*(1/4194304); 33554432*(1/8388608); 67108864*(1/33554432)

4

 

2

 

8

 

2

 

4

 

2

 

16

 

2

 

4

 

2

 

8

 

2

 

4

 

2

(4)

``

Thank you!

Greetings,

The Function

Download Mapleprimes_Book_2_Question_1.mw

I want to compute the series expansion of i3_r wrt (x, y, z) at point (x=y=z=0):

i2   := (x,y) -> -(1/2)*I*(exp(I*x)*(sin(x)/x)-exp(I*y)*(sin(y)/y))/(x-y):
i3_r := -(1/2)*I*(i2(y,z)-i2(y,x))/(z-x);

My first attempt was to compute this mulltiple series expansion this way:

ordre := 3:
sx := convert( series(i3_r, x, ordre), polynom);
sy := convert( series(sx  , y, ordre), polynom);
sz := convert( series(sy  , z, ordre), polynom);

But this gives me sy=sz=0 whatever the expansion order.

I then do this:

sx :=              convert(series(i3_r , x, ordre), polynom):
sy := add(map(u -> convert(series(u    , y, ordre), polynom), [op(expand(sx))])):
sz := add(map(u -> convert(series(u    , z, ordre), polynom), [op(expand(sy))]));

and obtained non zero results for both sy and sz (but are they are correct ?).

Could you explain me what happens and tell me how to find the series expansion of i3_r wrt (x, y, z) ?

TIA

restart

``

with(plots)

 

fixedparameter := [Nb = 0, Nt = 0, Bi = 1000, Le = 10]

[Nb = 0, Nt = 0, Bi = 1000, Le = 10]

(1)

DE1 := diff(f(eta), eta, eta, eta)+f(eta)*(diff(f(eta), eta, eta))-[diff(f(eta), eta)]^2 = 0

diff(diff(diff(f(eta), eta), eta), eta)+f(eta)*(diff(diff(f(eta), eta), eta))-[diff(f(eta), eta)]^2 = 0

(2)

``

DE2 := diff(theta(eta), eta, eta)+Pr*f(eta)*(diff(theta(eta), eta))+Pr*Nb*(diff(theta(eta), eta))*(diff(phi(eta), eta))+Pr*Nt*[diff(theta(eta), eta)]^2 = 0

diff(diff(theta(eta), eta), eta)+Pr*f(eta)*(diff(theta(eta), eta))+Pr*Nb*(diff(theta(eta), eta))*(diff(phi(eta), eta))+Pr*Nt*[diff(theta(eta), eta)]^2 = 0

(3)

DE3 := diff(phi(eta), eta, eta)+Le*(diff(phi(eta), eta))+Nt*(diff(theta(eta), eta, eta))/Nb = 0

diff(diff(phi(eta), eta), eta)+Le*(diff(phi(eta), eta))+Nt*(diff(diff(theta(eta), eta), eta))/Nb = 0

(4)

BC1 := f(0) = 0, f(eta) = 1-exp(-eta), (D(f))(0) = 1, (D(f))(10) = 0

f(0) = 0, f(eta) = 1-exp(-eta), (D(f))(0) = 1, (D(f))(10) = 0

(5)

BC2 := theta(10) = 0, (D(theta))(0) = -Bi*[1-theta(0)]

theta(10) = 0, (D(theta))(0) = -Bi*[1-theta(0)]

(6)

BC3 := phi(0) = 1, phi(10) = 0

phi(0) = 1, phi(10) = 0

(7)

``

L := [0.7e-1, .2, .7, 2, 7, 20, 70]; for k to 7 do R := dsolve(eval({BC1, BC2, BC3, DE1, DE2, DE3}, Pr = L[k]), [f(eta), theta(eta), phi(eta)], numeric, output = listprocedure); Y || k := rhs(R[5]); YP || k := -rhs(R[6]) end do

Error, (in dsolve/numeric/bvp/convertsys) unable to convert to an explicit first-order system

 

 

NULL

Download ODEprobz.mw

H.M.mw

restart

with(plottools):

with(plots):

with(CurveFitting):

with(Statistics):

Digits := 10:

L := point([0, 0, 0], color = blue, symbol = cross, symbolsize = 50), point([0, 0, 1], color = red, symbol = cross, symbolsize = 50), point([0, 1, 0], color = black, symbol = cross, symbolsize = 50):

display(L, axes = boxed, view = [-1 .. 1, -1 .. 1, -1 .. 1], orientation = [125, 65])

 

``

``

``

``

Download H.M.mw

Hi experts,

I have an equation. I tried to use subs command to substitute x with complex number p+iq in this equation and then separate the Re and Im part of the equation, but it does not work.

How can I do this?

How can I plot the Re and Im part of the equation vs y for some different parameters?

Equation:

eq.mw

I would like to open a specially formatted document from start/new document. I set  up one with a fixed width table to make it easy to print to A4. I find the very useful for taking notes.

Currently I just save it as  a usual document. The attached shows the basic setup I use. Contents arn't too relivant.

restart

``

 

 

 

"R(m2,m3,m4,...)≡((2 m2+3 m3+4 m4+...)!)/((1+m2+2 m3+3 m4+...)!m2!m3!m4!...)"

 

 

  

Xterm := factorial(2*m+3*n+4*p+5*q)*c[2]^m*c[3]^n*c[4]^p*c[5]^q/(factorial(1+m+2*n+3*p+4*q)*factorial(m)*factorial(n)*factorial(p)*factorial(q))

factorial(2*m+3*n+4*p+5*q)*c[2]^m*c[3]^n*c[4]^p*c[5]^q/(factorial(1+m+2*n+3*p+4*q)*factorial(m)*factorial(n)*factorial(p)*factorial(q))

(1)

k := 5

5

(2)

x := add(add(add(add(Xterm, q = 0 .. 4*k), p = 0 .. 3*k), n = 0 .. 2*k), m = 0 .. k)

nops(x)

22176

(3)

NULL

nops(TestPoly)

1

(4)

ldegree(TestPoly)

1

(5)

NULL

NULL

NULL
NULL

mtaylor(TestPoly, [c[2], c[3], c[4], c[5]], k+2)

TestPoly

(6)

C1 := 1; C2 := -2; C3 := 3; C4 := -4; C5 := 5

5

(7)

Poly1 := expand((y+C1)*(y+C2)*(y+C3)*(y+C4)*(y+C5))

y^5+3*y^4-23*y^3-51*y^2+94*y+120

(8)

NULL

Poly1 := Poly1/coeff(Poly1, y, 0)

(1/120)*y^5+(1/40)*y^4-(23/120)*y^3-(17/40)*y^2+(47/60)*y+1

(9)

NULL

Poly1 := expand((y+C1)*(y+C2)*(y+C3)*(y+C4)*(y+C5))

y^5+3*y^4-23*y^3-51*y^2+94*y+120

(10)

NULL

Poly1 := Poly1/coeff(Poly1, y, 0)

(1/120)*y^5+(1/40)*y^4-(23/120)*y^3-(17/40)*y^2+(47/60)*y+1

(11)

fsolve(Poly1, y)

-5., -3., -1., 2., 4.

(12)

coeff(Poly1, y, 1)

47/60

(13)

Poly2 := algsubs(y = -z/coeff(Poly1, y, 1), Poly1)

-(6480000/229345007)*z^5+(324000/4879681)*z^4+(41400/103823)*z^3-(1530/2209)*z^2-z+1

(14)

"(->)"

-0.28254e-1*z^5+0.66398e-1*z^4+.39876*z^3-.69262*z^2-1.*z+1.

(15)

"(->)"

 

solve(Poly2, z)

-47/30, -47/15, 47/12, 47/20, 47/60

(16)

-%/coeff(Poly1, y, 1)

2, 4, -5, -3, -1

(17)

NULL

 

 

``

``

NULL

Download A4_format.mw

How to add any/many subprocedure in a mainprocedure?
Somehow the mainprocedure must deliver the input for the mainprocedure

Here is a example 

Note: probably can this old procedure be rewritten in modern Maple programming language ?  

restart;

 

Code to Find the Max and Min Values in a List A

 

maxmin:=proc(A,maxv::evaln,minv::evaln)

   local i;

   maxv:=A[1]; minv:=A[1];

   for i from 2 to nops(A) do

     if eval(maxv) < A[i] then maxv:=A[i] end if;

     if eval(minv) > A[i] then minv:=A[i] end if;

   end do;

   RETURN()

end proc:

 

Now we can call the maxmin procedure from a procedure named optimize, which is designed to create the polygonal approximation, use maxmin to find the largest and smallest y-values from among the vertices, and produce some graphic output.

See the documentation in the book.

 

Code to Approximate the Max and Min Values of a Function  f :

 

optimize:=proc(f,a,b,N,pic::evaln)

  local X,Y,L,i,A,xmax,xmin;

  X:=array(0..N);Y:=array(0..N);L:=array(0..N);

  with(plots,display);

  for i from 0 to N do

    X[i]:=evalf(a+i*(b-a)/N);

    Y[i]:=f(X[i]);

    L[i]:=plot([[X[i],0],[X[i],Y[i]]],color=black):

  end do;

  A:=[seq(Y[i-1],i=1..N+1)];

  maxmin(A,maxv,minv); # USE OF SECOND PROCEDURE --------------

  xmax:={};xmin:={};

  for i from 0 to N do

    if Y[i]=maxv then xmax:=xmax union {X[i]} end if;

    if Y[i]=minv then xmin:=xmin union {X[i]} end if;

  end do; #----------------------------------------------------

  pic:=display({seq(L[i],i=1..N)}):

  print(`maximum y value is`,maxv,`and occurs at these x values`,xmax);

  print(`minimum y value is`,minv,`and occurs at these x values`,xmin);

  end proc:

 

Note that you must execute the code that defines maxmin before the procedure optimize will work. This only make sense.

 

We test the optimize procedure with the following function

 

f:=x->3+10*(-x^2+x^4)*exp(-x^2);

proc (x) options operator, arrow; 3+10*(-x^2+x^4)*exp(-x^2) end proc

(1)

on the interval [-1, 4].

 

optimize(f,-1,4,150,pic);

`maximum y value is`, 6.088066652, `and occurs at these x values`, {1.633333333}

 

`minimum y value is`, 1.391538737, `and occurs at these x values`, {-.6333333333, .6333333333}

(2)

pic;

 

 

Download procedure_en_subprocedures.mw

Hi. 

Just trying to replicate a calculation, I would expect close to absolute zero, but my units are out

Black_hole_temp.mw

finite difference method 

restart

with(ODETools)

unprotect('gamma')

unprotect(GAMMA)

Digits := 3

M := M; delta := delta; Ec := Ec; Pr := Pr; A := A; GAMMA := GAMMA; gamma := gamma; Q := Q; R := R; S := S; Sc := Sc

M

 

delta

 

Ec

 

Pr

 

A

 

GAMMA

 

gamma

 

Q

 

R

 

S

 

Sc

(1)

ODE1 := d(1+GAMMA)*(diff(f(eta), eta, eta, eta, eta))-S*(eta*(diff(f(eta), eta, eta, eta))+3*(diff(f(eta), eta, eta))+(diff(f(eta), eta))(diff(f(eta), eta, eta))-f(eta)*(diff(f(eta), eta, eta, eta)))-GAMMA*delta(2*(diff(f(eta), eta, eta))*(diff(f(eta), eta, eta, eta))^2+(diff(f(eta), eta, eta))^2*(diff(f(eta), eta, eta, eta, eta)))-M^2*(diff(f(eta), eta, eta)) = 0

d(1+GAMMA)*(diff(diff(diff(diff(f(eta), eta), eta), eta), eta))-S*(eta*(diff(diff(diff(f(eta), eta), eta), eta))+3*(diff(diff(f(eta), eta), eta))+(diff(f(eta), eta))(diff(diff(f(eta), eta), eta))-f(eta)*(diff(diff(diff(f(eta), eta), eta), eta)))-GAMMA*delta(2*(diff(diff(f(eta), eta), eta))*(diff(diff(diff(f(eta), eta), eta), eta))^2+(diff(diff(f(eta), eta), eta))^2*(diff(diff(diff(diff(f(eta), eta), eta), eta), eta)))-M^2*(diff(diff(f(eta), eta), eta)) = 0

(2)

ODE2 := (1+4*R*(1/3))*(diff(theta(eta), eta, eta))+Pr*S*(f(eta)*(diff(theta(eta), eta))-eta*(diff(theta(eta), eta))+Q*theta(eta)) = 0

(1+(4/3)*R)*(diff(diff(theta(eta), eta), eta))+Pr*S*(f(eta)*(diff(theta(eta), eta))-eta*(diff(theta(eta), eta))+Q*theta(eta)) = 0

(3)

ODE3 := diff(phi(eta), eta, eta)+Sc*S*(f(eta)*(diff(phi(eta), eta))-eta*(diff(phi(eta), eta)))-Sc*gamma*phi(eta) = 0

diff(diff(phi(eta), eta), eta)+Sc*S*(f(eta)*(diff(phi(eta), eta))-eta*(diff(phi(eta), eta)))-Sc*gamma*phi(eta) = 0

(4)

bc := f(0) = 0, (D(f))(0)^2 = 0, f(1) = 1, (D(f))(1) = 0, (D(theta))(0) = 0, theta(1) = 1, (D(phi))(0) = 0, phi(1) = 1

f(0) = 0, (D(f))(0)^2 = 0, f(1) = 1, (D(f))(1) = 0, (D(theta))(0) = 0, theta(1) = 1, (D(phi))(0) = 0, phi(1) = 1

(5)

``

(6)

parameter := [S = .5, GAMMA = .1, delta = .1, gamma = .1, M = 1, Pr = 1, Ec = .2, Sc = .6, R = 1, Q = 1]

[S = .5, GAMMA = .1, delta = .1, gamma = .1, M = 1, Pr = 1, Ec = .2, Sc = .6, R = 1, Q = 1]

(7)

SOL := dsolve({bc, subs(parameter, ODE1), subs(parameter, ODE2), subs(parameter, ODE3)}, type = numeric, method = bvp[middefer], output = listprocedure)

Error, (in fproc) unable to store '15.0099999999999998/d(1.1)' when datatype=float[8]

 

Sol := dsolve({bc, subs(parameter, ODE1), subs(parameter, ODE2), subs(parameter, ODE3)}, type = numeric, method = bvp[middefer], output = listprocedure, initmesh = 1024, abserr = 0.1e3)

Error, (in fproc) unable to store '15.0099999999999998/d(1.1)' when datatype=float[8]

 

SOL(1)

SOL(1)

(8)

NULL

``

Download FDM_EYRING_POWELL.mw

I can't move files in the navigator window anymore in Maple 2021.2.

Anyone else with the same problems?

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