Hello.

I am trying to extract all the coefficients of a linear equation by calling coeffs function.

I expected I receive the coefficients in the same order as in vars variable, but I was wrong. How to extract coefficients in the order I need?

Download test.mw

Dear users,

In my attached file I have two PDES, (PDE1 and PDE2). PDE1 is a function of v(t) and w(x,t) and PDE2 is also a function of v(t) and w(x,t). I can solve PDE2 if I say v(t) is 1 for example and you can see the plot. But what if I put v(t) back in PDE2 and want to find v(t) and w(x,t) from PDE1 and PDE2 together? 

Many Thanks,

Baharm31

Download Euler-Bernoulli_Beam-last_version.mw

I am having problems with the curly brackets in math mode. I am using a Danish keyboard, and since changing to Maple 17, the inline evaluation (usually [CTRL]+=) has been placed as [CTRL]+[ALT]+0 which - by Maple - is interpreted the same way as [ALT-GR]+0. Unfortunately [ALT-GR]+0 is the way to get the end-bracket for curly brackets, i.e. }

Therefore, I am not able to write } in math mode. Maple interprets my keystrokes as a wish to do inline evaluation when trying to write }.

Has anyone experienced this issue - and if so: Is there a way to fix it?

Is there a way to change the shortcut keys in Maple (e.g. make an alternative shortcut for inline evaluations)?

restart:with(plots):with(PDEtools):

 pde:=1/r*diff(r*diff(U(r,z),r),r)+1/b^2*diff(U(r,z),z,z)=0;

ans := pdsolve(pde);

ics:=(D[1](U))(0, z) = 0,(D[2](U))(r, 0)-B*U(r,0) = 0;

bcs:=(D[2](U))(r, 1)+B*U(r,1) = B,(D[1](U))(1, z)+B*U(1,z) = 0;

B:=1:b:=1:

S:= pdsolve(pde, {bcs, ics}, numeric);

Error, (in pdsolve/numeric) unable to handle elliptic PDEs

anyway around this?

RIZPDE.mw

I'm writing some code that computes a positive integer N and I'd like Maple to define a function of N variables. I've tried writing 

f := (seq(t[i],i=1..N))-> MY EXPRESSION;

but I receive the error

Error, invalid parameter; functional operators require their parameters to be of type symbol or (symbol::type)

Is there anything I can do here?

a:=rand(0..8):
b:=rand(0..8):
c:=rand(0..8):
d:=rand(0..8):
e:=rand(0..8):
f:=rand(0..8):
a()+b()+c()+d()+e()+f()=8;

This is my  programming code.

I want ot set six random summation is  8. 

But the random summation can't reach 8.

Dear all,

I want to compute the charateristic polynomials of some matrices (the number of matrices is more than 10000), and write the coefficients of the resulting polynomials to a text file. The entries of the given matrices are stored in a text file. More specifically, suppose that M_1, M_2 and M_3 are three matrices, and the entries of them are stored in a text file named "data.txt" in the following form:

1 2 3

4 5 6

7 8 9

1 -1 0

2 3 6

-3 0 2

2 1 -1

1 -1 -2

0 1 2

The resulting output file should be of the following format:

1, -15, 18, 0

1, -6, 13, -28

1, -3, 1, 3

I don't know how to repeatedly read the data from the given text file. I think the procedure should be as follows.

>restart:

>with(LinearAlgebra):

>with(FileTools:-Text):

>fid:=Open("data.txt"):

>fid_1:=Open("data_1.txt"): #data_1 is the output file

>ReadFile(fid); #since the number of matrices is very large, I want the data to be read once

>numlines:=CountLines(fid);

>for i from 1 to numlines do

       here I need repeatedly read the data to a matrix M (I don't know how to do);

       P:=CharacteristicPolynomial(M,x);

       writedata[APPEND]("data_1.txt",map(i-> coeff(p, x, i), [seq(i, i = 0 .. degree(p, x))]));  #this statement cannot write the coefficients of a polynomial in the same row

>end do;

>Close(fid):

>Close(fid_1):

Now as I'm pretty new to Maple, I don't know any better and can't seem to get any information out of the help documents. 

Thanks a lot.

hi.i am a problem for solve analytic double integration as blow,plese help me....Thanks alot

int(int((2*gamma*cos(psi)/(D-r*sin(theta)*sin(phi))-2*gamma*cos(psi)/(D+r*sin(theta)*sin(phi)))*r^2*cos(theta)*sin(phi), r = 0 .. L), phi = 0 .. Pi)

I UPLOAD THIS INTEGRAL AS FOLLOW;;;;;int.mw

Download int.mw

I want to extract all the coefficients of a polynomial. For example, let p:=x^5-8x^3+2, and the function coeffs(p) returns 1, -8, 2. In fact, I want to obtain 1, 0, -8, 0, 0, 2. Thanks to everyone.

The toggle button in the embedded components has a default image which points up and down. Is there any way to rotate this image so that it points left and right?  I though I might actually just rotate the default image gif(?) directly, but the properties window does not give the location of the gif(?) used for this image. I also can't locate the image file simply looking at the Maple program folder. Otherwise, I have to go find or create an image of my own.

I'm trying to plot the graph of a recursive function in Maple 17 but I keep getting the error Error, (in f) too many levels of recursion.

I need to plot a logarithmic graph in the range of x=1,...40. Here is the code:

with(plots); 
f:=x->(2.25*f(x-1)-0.5*f(x-2));
f(1):=1/3;
f(2):=1/12;
logplot(f(x),1..40);

How can I fix this problem? Maybe I need to write it in an iterative form, but I don't know how. Thank you very much for any help!

As I am trying to solve this integration:

restart; with(linalg); with(stats); with(plots); with(Statistics); with(LinearAlgebra); with(Optimization);
lambda0 := proc (t) options operator, arrow; gamma0+gamma1*t+gamma2*t^2 end proc;
lambda := lambda0(t)*exp(beta*s);
t1 := 145; t3 := 250; t2 := (t1+t3)*(1/2);
s := 1/(273.16+50); s1 := 1/(273.16+t1); s3 := 1/(273.16+t3); s2 := 1/(273.16+t2); gamma0 := 0.1e-3; gamma1 := .5; gamma2 := 0; beta := -3800;
c := 300; n := 200;
Theta := solve(1-exp(-(gamma0*tau1+(1/2)*gamma1*tau1^2+(1/3)*gamma2*tau1^3)*exp(beta*s1)) = 1-exp(-(gamma0*a+(1/2)*gamma1*a^2+(1/3)*gamma2*a^3)*exp(beta*s2)), a);

a := Theta[1];

Delta := solve(1-exp(-(gamma0*(a+tau2-tau1)+(1/2)*gamma1*(a+tau2-tau1)^2+(1/3)*gamma2*(a+tau2-tau1)^3)*exp(beta*s2)) = 1-exp(-(gamma0*b+(1/2)*gamma1*b^2+(1/3)*gamma2*b^3)*exp(beta*s3)), b);

b := Delta[1];

A1 := `assuming`([unapply(int(exp(beta*s1)*exp(-(gamma0*t+(1/2)*gamma1*t^2+(1/3)*gamma2*t^3)*exp(beta*s1))/(gamma0+gamma1*t+gamma2*t^`2`), t = N .. M), N, M)], [N > 0, M > 0]);
A2 := unapply(int(exp(beta*s2)*exp(-(gamma0*(a+t-tau1)+(1/2)*gamma1*(a+t-tau1)^2+(1/3)*gamma2*(a+t-tau1)^3)*exp(beta*s2))/(gamma0+gamma1*(a+t-tau1)+gamma2*(a+t-tau1)^2), t = N .. M), N, M);
A3 := unapply(int(exp(beta*s3)*exp(-(gamma0*(b+t-tau2)+(1/2)*gamma1*(b+t-tau2)^2+(1/3)*gamma2*(b+t-tau2)^3)*exp(beta*s3))/(gamma0+gamma1*(b+t-tau2)+gamma2*(b+t-tau2)^2), t = N .. M), N, M);
B1 := `assuming`([unapply(int(t^2*exp(beta*s1)*exp(-(gamma0*t+(1/2)*gamma1*t^2+(1/3)*gamma2*t^3)*exp(beta*s1))/(gamma2*t^2+gamma1*t+gamma0), t = N .. M), N, M)], [N > 0, M > 0]);
B2 := unapply(int((a+t-tau1)^2*exp(beta*s2)*exp(-(gamma0*(a+t-tau1)+(1/2)*gamma1*(a+t-tau1)^2+(1/3)*gamma2*(a+t-tau1)^3)*exp(beta*s2))/(gamma0+gamma1*(a+t-tau1)+gamma2*(a+t-tau1)^2), t = N .. M), N, M);
B3 := unapply(int((b+t-tau2)^2*exp(beta*s3)*exp(-(gamma0*(b+t-tau2)+(1/2)*gamma1*(b+t-tau2)^2+(1/3)*gamma2*(b+t-tau2)^3)*exp(beta*s3))/(gamma0+gamma1*(b+t-tau2)+gamma2*(b+t-tau2)^2), t = N .. M), N, M);

F0 := A1(0, tau1)+A2(tau1, tau2)+A3(tau2, c);
F1 := B1(0, tau1)+B2(tau1, tau2)+B3(tau2, c);

NLPSolve(1/(n^3*(F0*F1-F1)), tau1 = 115 .. 201, tau2 = 237 .. 273);

I need to have tau1 tau2 as varibles to get there optimal values ..

But this error keeps coming :

Error, (in Optimization:-NLPSolve) integration range or variable must be specified in the second argument, got HFloat(1.0) = HFloat(158.0) .. HFloat(255.0)

Please Help ..

I am a problem with solve differential equation, please help me: THANKS 

g := (y^2-1)^2; I4 := int(g^4, y = -1 .. 1); I5 := 2*(int(g^3*(diff(g, y, y)), y = -1 .. 1)); I6 := int(g^3*(diff(g, y, y, y, y)), y = -1 .. 1); with(Student[Calculus1]); I10 := ApproximateInt(6/(1-f(x)*g)^2, y = -1 .. 1, method = simpson);

dsys3 := {I4*f(x)^2*(diff(f(x), x, x, x, x))+I5*f(x)^2*(diff(f(x), x, x))+I6*f(x)^3 = I10, f(-1) = 0, f(1) = 0, ((D@@1)(f))(-1) = 0, ((D@@1)(f))(1) = 0};

dsol5 := dsolve(dsys3, numeric, output = array([0.]));

              Error, (in dsolve/numeric/bvp) system is singular at left endpoint, use midpoint method instead

****************FORMAT TWO ********************************************************

g := (y^2-1)^2; I4 := int(g^4, y = -1 .. 1); I5 := 2*(int(g^3*(diff(g, y, y)), y = -1 .. 1)); I6 := int(g^3*(diff(g, y, y, y, y)), y = -1 .. 1); with(Student[Calculus1]); I10 := ApproximateInt(6/(1-f(x)*g)^2, y = -1 .. 1, method = simpson);
dsys3 := {I4*f(x)^2*(diff(f(x), x, x, x, x))+I5*f(x)^2*(diff(f(x), x, x))+I6*f(x)^3 = I10, f(-1) = 0, f(1) = 0, ((D@@1)(f))(-1) = 0, ((D@@1)(f))(1) = 0};

dsol5 := dsolve(dsys3, method = bvp[midrich], output = array([0.]));
%;
                                   Error, (in dsolve) too many levels of recursion

I DONT KNOW ABOUT THIS ERROR

PLEASE HELP ME

THANKS A LOT

As am trying to solve this integration:

A(c,n,m):=evalf(int(1/(y)*exp(-c*y^(2)),y=n..m))

B(c,n,m):=evalf(int(exp(-c*y^(2)),y=n..m))

C(c,n,m):=evalf(int(y*exp(-c*y^(2)),y=n..m))

d(c,n,m):=evalf(int(y^(2)*exp(-c*y^(2)),y=n..m))

E(c,n,m):=evalf(int(y^(3)*exp(-c*y^(2)),y=n..m))

F0 := exp(beta*s1)*exp(gamma0^2*exp(beta*s1)/(2*gamma1))*A((1/2)*gamma1*exp(beta*s1), gamma0/gamma1,gamma0/gamma1+tau1)/gamma1+exp(beta*s2)*exp(gamma0^2*exp(beta*s2)/(2*gamma1))*A((1/2)*gamma1*exp(beta*s2), gamma0/gamma1+a, gamma0/gamma1+tau2-tau1+a)/gamma1+exp(beta*s3)*exp(gamma0^2*exp(beta*s3)/(2*gamma1))*A((1/2)*gamma1*exp(beta*s3), gamma0/gamma1+b, gamma0/gamma1+c-tau2+b)/gamma1

F1 := exp(beta*s1)*exp(gamma0^2*exp(beta*s1)/(2*gamma1))*(gamma0^2*A((1/2)*gamma1*exp(beta*s1), gamma0/gamma1, gamma0/gamma1+tau1)/gamma1^2-2*gamma0*B((1/2)*gamma1*exp(beta*s1), gamma0/gamma1, gamma0/gamma1+tau1)/gamma1+C((1/2)*gamma1*exp(beta*s1), gamma0/gamma1, gamma0/gamma1+tau1))/gamma1+exp(beta*s2)*exp(gamma0^2*exp(beta*s2)/(2*gamma1))*(gamma0^2*A((1/2)*gamma1*exp(beta*s2), gamma0/gamma1+a, gamma0/gamma1+tau2-tau1+a)/gamma1^2-2*gamma0*B((1/2)*gamma1*exp(beta*s2), gamma0/gamma1+a, gamma0/gamma1+tau2-tau1+a)/gamma1+C((1/2)*gamma1*exp(beta*s2), gamma0/gamma1+a, gamma0/gamma1+tau2-tau1+a))/gamma1+exp(beta*s3)*exp(gamma0^2*exp(beta*s3)/(2*gamma1))*(gamma0^2*A((1/2)*gamma1*exp(beta*s3), gamma0/gamma1+b, gamma0/gamma1+c-tau2+b)/gamma1^2-2*gamma0*B((1/2)*gamma1*exp(beta*s3), gamma0/gamma1+b, gamma0/gamma1+c-tau2+b)/gamma1+C((1/2)*gamma1*exp(beta*s3), gamma0/gamma1+b, gamma0/gamma1+c-tau2+b))/gamma1

F01 := exp(beta*s1)*exp(gamma0^2*exp(beta*s1)/(2*gamma1))*(B((1/2)*gamma1*exp(beta*s1), gamma0/gamma1, gamma0/gamma1+tau1)-gamma0*A((1/2)*gamma1*exp(beta*s1), gamma0/gamma1, gamma0/gamma1+tau1)/gamma1)/gamma1+exp(beta*s2)*exp(gamma0^2*exp(beta*s2)/(2*gamma1))*(B((1/2)*gamma1*exp(beta*s2), gamma0/gamma1+a, gamma0/gamma1+tau2-tau1+a)-gamma0*A((1/2)*gamma1*exp(beta*s2), gamma0/gamma1+a, gamma0/gamma1+tau2-tau1+a)/gamma1)/gamma1+exp(beta*s3)*exp(gamma0^2*exp(beta*s3)/(2*gamma1))*(B((1/2)*gamma1*exp(beta*s3), gamma0/gamma1+b, gamma0/gamma1+c-tau2+b)-gamma0*A((1/2)*gamma1*exp(beta*s3), gamma0/gamma1+b, gamma0/gamma1+c-tau2+b)/gamma1)/gamma1

`Fβ` := int((s1^2*(gamma0*t+(1/2)*gamma1*t^2)*exp(beta*s1)*(gamma1*t+gamma0)*exp(beta*s1))*exp(-(gamma0*t+(1/2)*gamma1*t^2)*exp(beta*s1)), t = 0 .. tau1)+int((s2^2*(gamma0*(a+t-tau1)+(1/2)*gamma1*(a+t-tau1)^2)*exp(beta*s2)*(gamma0+gamma1*(a+t-tau1))*exp(beta*s2))*exp(-(gamma0*(a+t-tau1)+(1/2)*gamma1*(a+t-tau1)^2)*exp(beta*s2)), t = tau1 .. tau2)+int((s3^2*(gamma0*(b+t-tau2)+(1/2)*gamma1*(b+t-tau2)^2)*exp(beta*s3)*(gamma0+gamma1*(b+t-tau2))*exp(beta*s3))*exp(-(gamma0*(b+t-tau2)+(1/2)*gamma1*(b+t-tau2)^2)*exp(beta*s3)), t = tau2 .. c)+int((s3^2*(gamma0*(b+t-tau2)+(1/2)*gamma1*(b+t-tau2)^2)*exp(beta*s3)*(gamma0+gamma1*(b+t-tau2))*exp(beta*s3))*exp(-(gamma0*(b+t-tau2)+(1/2)*gamma1*(b+t-tau2)^2)*exp(beta*s3)), t = c .. infinity)

I need to have tau2 as varibles to get there optimal values ..

Minimize(1/((F0*F1-F01^2)*n^3*`Fβ`), tau2 = 237..273})

But this error keeps coming :

Error, (in Optimization:-NLPSolve) integration range or variable must be specified in the second argument, got HFloat(1.0) = 121.0828419 .. HFloat(193.0828419)

Please Help ..

Dear all, 

I'm trying to extract the coefficients from the equation below, the fat expressions in the equation. I don't have any trouble seperating the sine or cosine functions. But the constants are a problem. Since t is the only variable in the function i tried, coeff(R, t, 0). This does not work apparantly. Any suggestions? 

R:=(1/12)*C2^3*cos(2*t) - (1/48)*C2^3*cos(4*t) - C2^3*sin(t) + C2^3*sin(3*t)-C2^2*C4*cos(t) + C2^2*C4*cos(3*t) - (1/8)*C2^2*C4*sin(2*t) + (1/16)*C2^2*C4*sin(4*t) + (1/16)*C2*C4^2*cos(4*t) - C2*C4^2*sin(t) - C2*C4^2*sin(3*t) - C4^3*cos(t) - C4^3*cos(3*t) - (1/24)*C4^3*sin(2*t) - (1/48)*C4^3*sin(4*t) - (1/16)*C2^3 - (1/16)*C2*C4^2 - (1/2)*C2*cos(2*t) + C2*sin(t) + C4*cos(t) + (1/2)*C4*sin(2*t) + (1/2)*C2