# MaplePrimes Questions

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### extracting data to a ascii-file for using in gnupl...

July 25 2014
1 4

hi maple-friends !

who can help me??

QUESTION 1:

i want to extract (export) the data of let me say the function y=x^2 ...

the result shpuld be:

without the variables !  (x=)   (y=)

1         1

2         4

3         9

and so on...

that means just a matrix...of numbers.

QUESTION 2:

and waht i have to do if i need more values, including non-integers as x (example: x=1.1, 1.2,1.2 ... )

sorry, im a maple beginner and a lot of the advices in the books are not very helpful !!!   maybe only written

for experts ??   so by the way, does anybody know about a REALLL good BEGINNER-book for maple?

thanx a lot !   :-)

### How to let maple add two arrays only with the coef...

July 25 2014
1 2

Let x:=2*[x_1,x_2,...,x_n];   y:=3*[x_1,x_2,...,x_n]; If I input x+y, it will turn out  5*[2x_1,2x_2,...,2x_n]; But I want to get  5*[x_1,x_2,...,x_n]. What should I do? Thanks!!

### why does dsolve return the trivial solution y(x) a...

July 25 2014
2 10

Maple 18.01, windows

restart;
ode:=2*a^2*y(x)-2*y(x)^3+3*a*(diff(y(x), x))+diff(y(x), x$2)=0; dsolve(ode,y(x)); returns y(x)=0 So does ode:=2*a^2*y(x)-20*y(x)^3+3*a*(diff(y(x), x))+diff(y(x), x$2)=0;

ode:=2*a^2*y(x)-200*y(x)^3+3*a*(diff(y(x), x))+diff(y(x), x$2)=0; ode:=2*a^2*y(x)-2000*y(x)^3+3*a*(diff(y(x), x))+diff(y(x), x$2)=0;

etc...

Is this a bug?

### Substract powers in a series...

July 25 2014
0 0

Hi,

I tried to obtain power of a series. I have the following input

***

assume(c<-10);
eq1:=2*x^a*y^b*(x+y)^c+3*x^(a+1)*y^(b+1)*(x+y)^(c+1);

f1:=map(t -> if(match(t = d*x^e*y^f*(x+y)^g, x, 's'), subs(s,e), NULL),
convert(eq1, list));

f2:=map(t -> if(match(t = d*x^e*y^f*(x+y)^g, y, 's'), subs(s,f), NULL),
convert(eq1, list));

f3:=map(t -> if(match(t = d*x^e*y^f*(x+y)^g, x+y, 's'), subs(s,g), NULL),
convert(eq1, list));

print(f1);

****

The output is

****

a b c (a + 1) (b + 1) (c + 1)
2 x y (x + y) + 3 x y (x + y)
[]
[]
Error, (in unknown) invalid input: match expects its 2nd argument, vv, to be of type {name, set(name)}, but received x+y
[]

***

How to get the correct powers of x, y, and (x+y)? Since the power of x+y is negative, it cannot be absorbed into x and y.

Thank you!

### Memory storage - Maple...

July 25 2014
1 5

Hello everybody,

I have to solve a non linear equation using a numerical method. I use a loop after each iteration, Maple keep the results in memory instead of release their in variable. So calculation time is very long and the memory goes up.

Could you help me to improve the calculation time ? In fact, I would like to store results in a list and maple erases each intermediate results.

Thank a lot

[carré]NewmarkAlgo2FCzAlp.mw

### How to create a "rating" question?...

July 25 2014
2 2

How do you create a "rating" question type in Maple T.A.? I.e. a question of the following kind:

"rate this and that" and ask the students to select an answer from the list {1, 2, 3, 4, 5}. To this kind of question there is no correct answer. The grade should be the chosen number.

Edit: I just found that this kind of question is called a "Likert-scale question".

### Output to Latex...

July 24 2014
0 2

I run the command

> latex( '(3*p^4+3*p^2-2*p+1)/((1-p+p^2)*(1-3*p+3*p^2))' );

and I get

{\frac {3\,{p}^{4}+3\,{p}^{2}-2\,p+1}{ \left( 1-p+{p}^{2} \right)
\left( 1-3\,p+3\,{p}^{2} \right) }}

for some reason before every variable p I get a backslash and comman, \, and the frac{}{} command is always written as \frac {}{}, which isn't valid latex syntax, etc.  What's going on?

### Spiral Matrix Procedure in Maple...

July 24 2014
2 3

I am wanting to write a procedure to take a square matrix and have it output a spiral matrix.

for example; M:=Matrix(3,[[1,1,1],[2,2,2],[3,3,3]]);

would turn into

S:=Matrix(3,[[1,1,1],[3,3,2],[3,2,2]]);

Starting in the top left corner and each row follows around clockwise until you reach the middle.

My first thought was I need to be able to call each element (m_i,j) from a matrix and tell it where to go. I could write a different procedure for each square matrix assigning where the elements in the matrix each should move to. Since I could not get it to work for n.

Here is what i have for a 3x3 matrix

Spiral := proc(a1,a2,a3,b1,b2,b3,c1,c2,c3)
local M,S;
M:=Matrix(3,[[a1,a2,a3],[b1,b2,b3],[c1,c2,c3]]);
S:=Matrix(3,[[a1,a2,a3],[c2,c3,b1],[c1,b3,b2]]);
print(M);
print(S);
end:
Spiral(1,2,3,4,5,6,7,8,9);

It is very difficult for me to find information about Matrices in Maple. Any hint on using Maple would be appreciated. Thank you.

### Bilevel optimization...

July 24 2014
0 3

Dear all

is it possible to solve bilevel optimization problems in maple?

min F(x,y)

s.t.    min G(x,y)

s.t.   k(x,y)<=0

### Return Unused Memory back to operating system (Des...

July 24 2014
1 10

Hi,

I have a code which stores large amount of intermediate data.

Ones the data has been used i unassign the variables storing the data and perform garbage collection. But memory is not returned to the operating system for reallocation.

can somebody please tell me how to release memory back to os so that task manager shows memory release (without doing the maple server reset).

And i dont understand the purpose of stupid gc if it is not returning memory back to the windows?

### too many levels of recursion when trying to plot r...

July 23 2014
1 5

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!

### backtransform in 3D...

July 23 2014
0 2

Hello everyone,

how exactly do i 3-d plot some data that i have to back-transform first. in 2-d it is so easy. why isnt it in 3d? all i end up with is an all black diagram

transformIT.mw

Grateful for some hints

Goon

### solve system symbolic...

July 22 2014
0 12

Hello every one,

I had a 3 equations with 3 unknown (X,Y,Z, conjugate(Y),conjugate(Z))

this is the code:

solve( {ao*x + a1*y + conjugate(a1)*conjugate(y)+a2*z+conjugate(a2)*conjugate(z) = 0.5, conjugate(a1)*x + bo*y + conjugate(a2)*conjugate(y)+a1*z = 0, 10*x + 10*y/4 + 10*z = 10}, {x, y, z});

where the coefficients are complex numbers

Is thee any simple way to solve it

thanks

### solve the nonlinear ode equations...

July 22 2014
0 4

Hi:

i will solve the five nonlinear coupled odes with maple in least time,can evey body help me?

eq1:= -3515.175096*Pi*q[1](T)*q[4](T)-3515.175096*Pi*q[1](T)*q[5](T)-2650.168890*Pi^2*q[3](T)*q[1](T)-9.871794877*10^7*q[2](T)*Pi+.5622514683*(diff(q[1](T), T, T))+1.893468706*q[1](T)^3*Pi^4+2.507772708*10^5*q[1](T)*Pi^2=0

eq2:= 496.9066665*q[2](T)*Pi^2-380.5288665*q[4](T)*Pi-62694.31768*Pi*q[1](T)+380.5288665*q[5](T)*Pi+0.3570776400e-3*(diff(q[2](T), T, T))+2.467948718*10^7*q[2](T)=0

eq3:= 2650.168888*q[1](T)^2*Pi^2+7.824250847*10^5*q[3](T)*Pi^2+1.037806000*10^6*q[5](T)*Pi+.5622514682*(diff(q[3](T), T, T))+1.037806000*10^6*q[4](T)*Pi=0

eq4:= 63661.97724-241.8620273*q[1](T)*(diff(q[1](T), T))-6.792272727*10^6*(diff(q[4](T), T))-5191.348749*q[4](T)-5191.348749*q[5](T)+71406.36133*(diff(q[3](T), T))-6.792272727*10^6*(diff(q[5](T), T))=0

eq5:= 70.02817496+2490.500000*(diff(q[5](T), T))-29887.90351*q[4](T)+29887.90351*q[5](T)-2490.500000*(diff(q[4](T), T))-45.34913011*(diff(q[2](T), T))=0

### Dear Friends Help a Maple Dude :...

July 22 2014
1 7

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)