MaplePrimes Questions

How can I get maple to integrate this expression numerically.

For a specific value 0<s<1 it should be enough to integrate from -40..40 instead of -infinity..infinity

Anyway. My maple version always hangs up :-(

(1/2)*(-4*dilog(-(exp(2*t)*s-(-s^2+1)^(1/2)+1)/(-1+(-s^2+1)^(1/2)))*exp(4*t)+arctanh((-1+s)/(-s^2+1)^(1/2))*s^2+arctanh((exp(2*t)*s-exp(2*t)-s+1)/((exp(2*t)+1)*(-s^2+1)^(1/2)))*s^2+8*(-s^2+1)^(1/2)*exp(4*t)+4*dilog((exp(2*t)*s+(-s^2+1)^(1/2)+1)/(1+(-s^2+1)^(1/2)))*exp(4*t)+4*exp(4*t)*arctanh((-1+s)/(-s^2+1)^(1/2))-8*arctanh((exp(2*t)*s-exp(2*t)-s+1)/((exp(2*t)+1)*(-s^2+1)^(1/2)))*exp(4*t)*s^2*t-4*ln(1+(-s^2+1)^(1/2))*exp(4*t)*s^2*t+4*ln(1-(-s^2+1)^(1/2))*exp(4*t)*s^2*t-4*ln(exp(2*t)*s-(-s^2+1)^(1/2)+1)*exp(4*t)*s^2*t+4*ln(exp(2*t)*s+(-s^2+1)^(1/2)+1)*exp(4*t)*s^2*t+12*(-s^2+1)^(1/2)*exp(4*t)*t-16*arctanh((exp(2*t)*s-exp(2*t)-s+1)/((exp(2*t)+1)*(-s^2+1)^(1/2)))*exp(4*t)*t-8*ln(1+(-s^2+1)^(1/2))*exp(4*t)*t+8*ln(1-(-s^2+1)^(1/2))*exp(4*t)*t-8*ln(exp(2*t)*s-(-s^2+1)^(1/2)+1)*exp(4*t)*t+8*ln(exp(2*t)*s+(-s^2+1)^(1/2)+1)*exp(4*t)*t-(-s^2+1)^(1/2)*exp(2*t)*s+8*arctanh((exp(2*t)*s-exp(2*t)-s+1)/((exp(2*t)+1)*(-s^2+1)^(1/2)))*exp(2*t)*s+4*exp(2*t)*arctanh((-1+s)/(-s^2+1)^(1/2))*s-(-s^2+1)^(1/2)*exp(6*t)*s-8*arctanh((exp(2*t)*s-exp(2*t)-s+1)/((exp(2*t)+1)*(-s^2+1)^(1/2)))*exp(6*t)*s+4*exp(6*t)*arctanh((-1+s)/(-s^2+1)^(1/2))*s+2*dilog((exp(2*t)*s+(-s^2+1)^(1/2)+1)/(1+(-s^2+1)^(1/2)))*exp(4*t)*s^2+2*(-s^2+1)^(1/2)*exp(4*t)*s^2-arctanh((exp(2*t)*s-exp(2*t)-s+1)/((exp(2*t)+1)*(-s^2+1)^(1/2)))*exp(8*t)*s^2+exp(8*t)*arctanh((-1+s)/(-s^2+1)^(1/2))*s^2+2*exp(4*t)*arctanh((-1+s)/(-s^2+1)^(1/2))*s^2-6*(-s^2+1)^(1/2)*ln(exp(4*t)*s+2*exp(2*t)+s)*exp(4*t)+6*(-s^2+1)^(1/2)*ln(s)*exp(4*t)-2*dilog(-(exp(2*t)*s-(-s^2+1)^(1/2)+1)/(-1+(-s^2+1)^(1/2)))*exp(4*t)*s^2)/((-s^2+1)^(1/2)*exp(8*t)*s^2-2*arctanh((-s^2+1)^(1/2)/(1+s))*exp(8*t)*s^2+4*(-s^2+1)^(1/2)*exp(6*t)*s-8*arctanh((-s^2+1)^(1/2)/(1+s))*exp(6*t)*s+2*(-s^2+1)^(1/2)*exp(4*t)*s^2-4*arctanh((-s^2+1)^(1/2)/(1+s))*exp(4*t)*s^2+4*(-s^2+1)^(1/2)*exp(4*t)-8*arctanh((-s^2+1)^(1/2)/(1+s))*exp(4*t)+4*(-s^2+1)^(1/2)*exp(2*t)*s-8*arctanh((-s^2+1)^(1/2)/(1+s))*exp(2*t)*s+(-s^2+1)^(1/2)*s^2-2*arctanh((-s^2+1)^(1/2)/(1+s))*s^2)

I have an equation as follows:

By inspection one can see that the last three terms can be simplified (factored) to

How can I coerce Maple to do this? None of the available tools seem to be getting close to this. A partial solution is like this: Writ a procedure as follows:

Fac:=proc(xpr,a,b);
  tmp:=xpr+(a^2+2*a*b+b^2);
  return tmp-(a+b)^2;
end proc;

and then call it:

Fac(lhs(eq),k0,2*Pi*n/L)=rhs(eq);

to get

which is what I want. But procedure Fac() is not general at all; e.g. it fails if the overall sign of the polynomial terms are different. There does not seem to be any way in Maple to determine the sign of a term in the sum of lhs(eq), I can only find ways to determine signs of a simple indeterminate. I'd like to make this procedure more general (which is trivial enough for a human) but I just cannot find any tools in Maple to support this.

Any ideas out there?

Mac Dude.

 

after a matrix operation, the result is not exactly the matrix i want

there is around 0.0001 difference difference in all element in matrix

how to deal with this random difference in order to be exact?

In order to get a little acquainted with the Grassmannian capabilities of the Physics package, I presently consider the following simple setup:

with(Physics):
Setup(
   mathematicalnotation = true,
   anticommutativepre   = theta
):
A := Matrix(2,(i,j) -> theta||i||j);
B := A . A;
C := Expand(B);

producing for A, B, and C the following results:

To me the [2,2]-entry of B seems erroneous: the first addend has the wrong ordering of the theta's, or, equivalently, the wrong sign. Not so surprisingly, this error is then present also in the [2,2]-entry of C. But in C, the [1,2]- and [2,1]-entries seem erroneous as well: the sign of theta11 in the [1,2]-entry is wrong, and so, too, is the sign of theta22 in the [2,1]-entry.

Have I fundamentally misunderstood something?

Hi everyone,

I have a very complicated function y with only one independent variable x, and want to fit or approximate it by a simpler function, say polynomial. Many books or maple reference seem to tell how to fit a set of data instead of a given function. But the argument x in the function is assumed to be continuous other than discrete, so I don't know whether it is possible to express datax in form of x's range such as 0..1, and express datay in form of the function. After that , maybe I can fit the two created data sets by a polynomial function.

Or, does anyone have a better or more direct way to do the fitting linking two fucntions?

I am appreciated for your help.

Best,

GOODLUCK

I have the following expression (obtained from an earlier calculation):

I want to collect all the terms under one summation. So I define a rule:

collectf:=proc(f)
A::algebraic*f(a::algebraic)+B::algebraic*f(b::algebraic)\
 +C::algebraic*f(c::algebraic)+D::algebraic*f(d::algebraic)=f(A*a+B*b+C*c+D*d);
end proc:

and then

applyrule(collectf(Sum),%);

I get

Error, (in +) unable to identify A::algebraic

I used similar constructs before so I think the rule is constructed correctly. I should, however, mention that I use the Physics:-Vectors package and in fact the expression I start up with here reads, in 1-d Maple inputform:

Physics[Vectors][`+`](Physics[Vectors][`+`](Physics[Vectors][`+`](-y*(Sum((diff(a[n](r), r))/(exp(I*Pi*n/L))^2, n))/r, (2*I)*(Sum(a[n](r)/(exp(I*Pi*n/L))^2, n))*k0), y*(Sum(a[n](r)/(exp(I*Pi*n/L))^2, n))*k0^2), -y*(Sum((diff(a[n](r), r, r))/(exp(I*Pi*n/L))^2, n)))

Is my problem related to the use of Physics:-Vectors? If so, how can I get around that?

TIA,

Mac Dude

How can I show the expression of the following summation as the output, not 11?

3+7+1

 

Hi all and happy new year

First I am a beginner in Maple and I want to solve an equation, but I obtain a complexe result with this _Z, my equation is 6th order and the unkown is alpha:

I tried these instructions but without resul:

z := solve(my eq,alpha)
zsol := allvalues(z)
evalf(zsol)

And I get this result

I want a simple result and what is the meaning of _Z

 For some reason maple does not simplify root in the following cases: 

sqrt((c^2, r^2));

another one is

sqrt(4), ....


Such square roots occur after this command:

eigenvectors := simplify(simplify(evectors, g * (g - 1) * (e - u * u + v * v + w * w) * 1/2 = c * c), sqrt, simbolic)

Looking at the code of PDEtools:-declare, one sees that it does some brief initializing and then passes the job off to `PDEtools/declare`. I'd like to view this latter procedure, but I can't find it. It is not at the top level, nor is it an export or local of module PDEtools. So where is it?

How to find the sum of the products given below

where I couldn't write j not equal to i in the product. 

sum(a[i],i=1..n)*product(s-b[j],j=1..n)

Has anyone an idea how to integrate

int(t^2/(1+s*cosh(2*t))^2,t=-infinity..infinity)

0<s<1

FirstEigenVector := Matrix(3, 1, {(1, 1) = -.736895432967255+0.*I, (2, 1) = -.588906969844997+0.*I, (3, 1) = -.331924240964690+0.*I});
SecondEigenVector := Matrix(3, 1, {(1, 1) = -.589856901397123+0.*I, (2, 1) = .320280857681335+0.*I, (3, 1) = .741275257969058+0.*I});
ThirdEigenVector := Matrix(3, 1, {(1, 1) = .330233185410229+0.*I, (2, 1) = -.742030156443046+0.*I, (3, 1) = .583384341736151+0.*I});
LHS := ProjOfEigenVector;
LHS := Matrix(3, 3, {(1, 1) = -.736895432967255+0.*I, (1, 2) = -.589856901397123+0.*I, (1, 3) = .330233185410229+0.*I, (2, 1) = -.588906969844997+0.*I, (2, 2) = .320280857681335+0.*I, (2, 3) = -.742030156443046+0.*I, (3, 1) = -.331924240964690+0.*I, (3, 2) = .741275257969058+0.*I, (3, 3) = .583384341736151+0.*I});
RHS := c1*FirstEigenVector+c2*SecondEigenVector+c3*ThirdEigenVector;
RHS := Matrix(3, 1, {(1, 1) = (-.736895432967255+0.*I)*c1+(-.589856901397123+0.*I)*c2+(.330233185410229+0.*I)*c3, (2, 1) = (-.588906969844997+0.*I)*c1+(.320280857681335+0.*I)*c2+(-.742030156443046+0.*I)*c3, (3, 1) = (-.331924240964690+0.*I)*c1+(.741275257969058+0.*I)*c2+(.583384341736151+0.*I)*c3});
solve([LHS[1][1] = RHS[1][1], LHS[2][2] = RHS[2][1], c1^2+c2^2+c3^2 = 1], [c1, c2, c3]);

 

after calculated the projection matrix, 

it is a 3*3 matrix on left hand side

however, combination of eigenvectors on right hand side is 3*1 matrix

when calculated c1,c2,c3 under the condition c1^2+c2^2+c3^2 = 1

how to know whether LHS[1][1] = RHS[1][1], or LHS[1][2] = RHS[1][1] or

LHS[1][3] = RHS[1][1]

How to create a borel set from a list of decimal

if i interpolate three decimal number and solve it, 

if any number substitute into this result which is a inverse function, can the results be said borel set?

with(LinearAlgebra):
t:=1;
NewMatrix3 := Matrix([[test10, close3(t) , close3(t+1)],
[close3(t) , close3(t+1) ,0],
[close3(t+1) , 0,0]]);

Matrix(3, 3, {(1, 1) = test10, (1, 2) = 5.59, (1, 3) = 5.74, (2, 1) = 5.59, (2, 2) = 5.74, (2, 3) = 0, (3, 1) = 5.74, (3, 2) = 0, (3, 3) = 0})

NewEigenMatrix := Eigenvalues(NewMatrix3);
solve([MatrixMatrixMultiply(NewMatrix3,Matrix([[x],[y],[z]]))[1][1] = NewEigenMatrix[1]* Matrix([[x],[y],[z]])[1][1],
MatrixMatrixMultiply(NewMatrix3,Matrix([[x],[y],[z]]))[2][1] = NewEigenMatrix[1]* Matrix([[x],[y],[z]])[2][1],
MatrixMatrixMultiply(NewMatrix3,Matrix([[x],[y],[z]]))[3][1] = NewEigenMatrix[1]* Matrix([[x],[y],[z]])[3][1]]
, [x,y,z]);

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