## how do I define a variable and a same variable na...

hello

as described in the title

what i want to define are these

but i get this

as the result of expression of

I wonder what I should do to get this?

i.e define them at the same time.

best regards,

Memdream.

## Nonlinear equations ...

Hi , I have question about poincare's theorem which needs to change the veriable and that transform the coordinates , but when I change the variable from x to y if doesn't defined any suggestion ? Please

## Why don't i assign the result of a optimization to...

I have excuted a loop for i from.....by...while.....do l2:=NLPSolve(.......) with variables, t1,th,tl, etc. I need get the numerical result of theses variables and assign them to t1,th, etc. After execute a function with them. I have tried with op, map and assign, but the program don't understand the numerical value of variables. Why?. How can i assign theses numerical vaules?. Thanks!

## Optimization with Boolean variables...

I know how to use Maple for an optimization problem contaning continous variables but I couldn't find anything in help of Maple related to use boolean variables in optimization. So assume I want to minimize a function that one of its variables only can take 0 and 1 as its value. Anyone knows how to introduce those to the Maple? For example you can look at this link that Matlab can do many of these kind of optimizations.

## Nondimensionalization of ODE...

Can some one help me " How to conert a three or four coupled equation by using non dimensions variable "

## Eliminating x=x in solve output...

I am using the solve command and the independent variables are in the form x=x. How can I output the solution as a list [set of solutions,independent variables]? The command select(z->symbol=symbol,S), where S is my set of solutions, does not work.

## Flexible Beam State Variables ...

I'm trying to run c code generated from a simple MapleSim example (Spin Up Beam). To makes things even simpler, I set the input real expression to just time, and changed the input function in my c code to:

static void inpfn(double T, double *U)
{
U[0] = T;
}

I set all the state variables to 0 for the initial conditions. I ran the code and my output doesn't resemble the MapleSim output at all, and I'm getting errors. So my question is about the state variables, which I initially set to 0:

* State variable(s):
* x[ 0] = `Main.SpinUpBeam.FB3.uf1`(t)
* x[ 1] = diff(`Main.SpinUpBeam.FB3.uf1`(t),t)
* x[ 2] = `Main.SpinUpBeam.FB3.uf2`(t)
* x[ 3] = diff(`Main.SpinUpBeam.FB3.uf2`(t),t)
* x[ 4] = `Main.SpinUpBeam.FB3.vf1`(t)
* x[ 5] = diff(`Main.SpinUpBeam.FB3.vf1`(t),t)
* x[ 6] = `Main.SpinUpBeam.FB3.vf2`(t)
* x[ 7] = diff(`Main.SpinUpBeam.FB3.vf2`(t),t)

What do these represent for this flexible beam (FB3)? I.e. what is uf1, uf2, vf1, vf2? Should they be set to 0, or no?

Thanks.

## Coding and simple algorithms ...

Hello,

Im a chemical engineer student with very little knowledge of Maple and its possibilities (which seem endless). I have very little coding experience, even though i do write in LaTeX (which i suppose is referred to as pseudo-code).

I figured, that as a student, i often run into the same number x problems, that each can be solved in x different ways. Since Maple is so good with units and calculations, aswell as defining variables. I could make some very smart notes, which would allow me to solve different (mostly simple) problems in a very easy and fast manner.

Now, since i dont know much about Maple, i want to seek som help.

How do i proceed to make such a document / multiple documents for my purpose? My first idea was to simply create a bunch of different variables defined to a given input, and then simply change the variables as i get a new problem. But i figured that there must be smarter and more neet ways to make this.

Let me know what you think.

Sincerely, Mikkel.

## Vector of symbolic variables...

Hi everyone,

I wanted to know if it was possible to store symbolic variables in a vector because I have a function of 10 variables which I want to write with Σ, Π and A(l), A being my vector of symbolic variables...

Benjamin

## How to enlarge number of variables?...

1.

with(RegularChains):
with(ConstructibleSetTools):
source1 := PolynomialRing([a,b,c]);
target1 := PolynomialRing([e1,e2,e3,e4]);
source1list := [eq2a, eq3a,eq4a];
target1list := [eq2b, eq3b, eq4b,eq5b];
cs := PolynomialMapPreimage(target1list, source1list, source1, target1);

Error, (in RegularChains:-ConstructibleSetTools:-PolynomialMapPreimage) number of map functions is different from number of variables in target space

in maple 15 do not have error, however now it has error for the code below

with(RegularChains): with(RegularChains): with(ConstructibleSetTools):

source1 := PolynomialRing([e1, e2, e3]);
target1 := PolynomialRing([a, b, c]);
source1list := [-1*e1+2*e2+*e3, -1*e1+2*e2+*e3, -1*e1+2*e2+*e3];
target1list := [.....]; cs :=
PolynomialMapPreimage(target1list, source1list, source1, target1);

Error, invalid product/quotient

## Error in pdsolve...

Hi everyone.

I have been experiencing a problem trying to solve a coupled system of 3 differencial equations

My problem is that a got a message back as I try to solve the system:

"Error, (in pdsolve/numeric/process_IBCs) improper op or subscript selector"

by apply this point that ''all dependent variables must be functions of the same independent variables''

i again accost with another error ''

Error, (in pdsolve/numeric/process_IBCs) initial/boundary conditions can only contain derivatives which are normal to the boundary, got (D[1, 1](w))(x, -3/400000000)

''

## Split a polynomial ...

Given a polynomial in several variables is it possible to split it so that all the coefficients of the monomials are +1 or -1.

Example:

p:=-z+2*x+4*y-3*x*y.

I would lie to obtain

f:=-z +x+x +y+y+y+y -x*y-x*y-x*y.

## Extract the variables from parametric polynomial i...

Let I  be a polynomial in K[A][X] s.t. A is a sequence of parameters (coefficients of f in F) and X is a sequence of variables. I want to extract the variables from ideal I.

For example if I=[(a-1)x*y^2-b+x, x-y+x^2-c] s.t. a,b,c are parameters and x,y are variables. I want {x,y} as the output of algorithm.

## extract the matrix coefficient of polynomial matri...

Let M be a matrix with polynomial array f_i's such that any array is in K[a_1,..,a_m][x_1,..,x_n] where a=a_1,,,a_m are sequence of parameters and x=x_1,..,x_n are sequense of variables. Now, I want to extract the coefficients of  f_i that are in K[a_1,a_2,..,a_m]. For example if how can I extract the matrix coefficint ?

Please note that a,b,c,d are parameters and x,y are variables.

## How to assign a value to each of the variables of ...

My problem is the following; Let's say that I want to make a simple program of designing of a steel beam. In order to do so, there is a respectable number of parameters that have to be taken into account - forces, geometrical characteristics etc -. So for example, I have an excel file that has the following rows

1) A row of variables  :                          LENGTH   MOMENT_OF_INERTIA   AXIAL_FORCE    HEIGHT_OF_SECTION

2)A row of a value for each one variable :      5                556                       130                       300

the traditional approach in maple to intoduce these values to the program would be:

LENGTH:=5
MOMENT_OF_INERTIA:=556
AXIAL_FORCE:=130                etc etc

and then when for example we write

MOMENT_OF_INERTIA/LENGTH       we get

556/5=111.2

..but for problems like this the variables may be 50 in number, even more.. and it would be very timeconsuming to define all these parameters one by one..
so what I have been looking for so much these days is a predefined maple procedure - if there is one.. - that takes a matrix which we have created in advance and that includes all the names of the variables that we want to have in the problem - let's name it VARIABLES - takes as well a matrix that we also have created in advance and includes the value that we want each of our variables to get in the problem - let's name it VALUES - and make the correspondense automatically, so as to when we introduce an epression in maple thereafter, like     MOMENT_OF_INERTIA/LENGTH, when we press enter to get  556/5=111.2  (and not just a reproducing of what we already wrote , MOMENT_OF_INERTIA/LENGTH ..).. Do you think that there is an easy way to do so??