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Hi, i got a litlle problem with fromats, i m realy bad at this.
i got procedure 'getone(z::list)' i was execute it like this  
>getone([seq(lineP[i], i = 1 .. pm)]::list)
where lineP is 

>pm := 3;
>rollx := rand(98.0 .. 102.0); rolly := rand(-1.0 .. 5);
>rolll := rand(.5 .. 1.0); rollf := rand(0. .. evalf(2*Pi));
>rollm := rand(0. .. 20.0);

>for i to pm do lineP[i] := [rollx(), rolly(), rolll(), rollf(), rollm()] end do;

it's pm times of z:=[rollx(), rolly(), rolll(), rollf(), rollm()] ::list

and i need make optimization work for any pm=1..100; with rabdomly generated iteration point as above.

The main queston is how make minimize as below
Minimize(z,variables=[z],   initialpoint={z=[seq(lineP[i], i = 1 .. pm)]},iterationlimit=1000,optimalitytolerance=0.01)

work with z::list kind of 

[[100.7798614, 1.109653266, 0.9840371500, 4.257816686, 9.737110573][100.0135459, 0.887539481, 0.9144164697, 3.980093624, 7.343851161][100.0661308, 3.724268229, 0.5020544909, 2.052134822, 14.37408543]]

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)


please help me.....very very thanks

In Maple TA in blackboard I am creating an assignment. Each week a part of the assignment will be posted. I was wondering if it is possible to have the same random variables in differnet assignmemts. That way the students can use their prior work. 

So in week one the students will get a set of random variables. But in week two a new assignment is posted were I want the same variables to come up for each student. Is this possible? (all students will have their own unique set of variables)

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



I would lie to obtain

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

Hi, I have 10 equation system and 10 unknown variables. I however, want to reduce the equations to 2 with two unknowns. I'm wondering how this could be done in maple. The variables are Y, q, yd, y*, yx, H,  pd, w, P and Pv. I intend to solve the equations for Y and w. 

Thanks in advance for your help. The maple file has also been attached.




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.

1. how to eliminate the diff(*(x,y,z),x) terms in an expression, "*" means any function which have independent variables x,y,z?

2. how to get the gradient of a vector, which should be a tensor?

 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 M=Matrix([[ax-bxy],[cx^2-dy]]) how can I extract the matrix coefficint C=Matrix([[a,-b],[c,-d]])?

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


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:

AXIAL_FORCE:=130                etc etc

and then when for example we write



..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??

many thanks in advance!

Hello maple users,

I want to compare 5 functions and see which one gives the best result (highest score). Unfortunatelly, I can't say one function always gives higher results than others. I have 8 variables and it makes the comparison complicated.

I assume 4 of them are constant and the other 4 or not.





for Pb= 0:0.025:0.20                   Pb and Pa are probabilities, between 0-20, 0.025 increments
    for Pa= 0:0.025:(Pb-0.025)      ** Pa is always less than Pb
        for Ha= 0:50                      Ha takes values between 0-50
            for Hb= 0:(Ha-1)            ** Hb is always less than Ha

I attached the data file. I appreciate if someone tells me how to compare these functions. Should I put more assumptions to make it easier? Thank you.


I was trying to find the solution for two theta variables in a couple of simultaneous equations (infact this is an iverse kinematics problem for a two link system pendulum).
The following are the initial inputs/equations to be manipulated:

Then I use the folowing command to rearrange for the theta values which I am after:

which gives me the result:

This is all fine until I give in values for l1, l2, x and y:


I have a RootOf in there with a _Z term poping up here and there. I know that this configuration of the two link mechanism in fact dows have a solution and that these numbers are reasonable. Thus I have three questions:

Why does this happen?
What does the "signum" mean here?
how do I go about getting the nummerical values?

Many thanks,
- pjf



I am new to Maple and have a problem when solving three equations with three variables. But when  I plug in into solve function then it gives no answer.

eqn1 := 24900 = A*exp(-X*1.293995859*10^22)+A*exp(-Y*1.293995859*10^22)+5852.27;

eqn2 := 6000 = A*exp(-X*1.293995859*10^22)+2422.929937;

eqn3 := 19100 = A*exp(-Y*1.293995859*10^22)+8275.199937;

Variables are [A,X,Y]

A customer on Twitter recently asked why Maple gives the following result:



The issue here is that the t in f(t) is the same as the integration variable. 140 characters is not a lot to work with for a reply, so here is a longer explanation.


First, note that the process of integration treats the integration variable differently than the other variables, so that replacing another variable by the integration variable has a different effect depending on whether the replacement is done before or after the integration is performed. Consider this simple example:


a := int(t, t)



eval(a, t = x)



a := int(x, t)




eval(a, t = x)




In other words, integration does not commute with substitution. This is a fundamental property of integration and in fact, Maple's eval has special rules to take this into account when you ask it to replace the integration variable.  For example, if you evaluate the inert form of the integral at x = y, the substitution is performed explicitly:



eval(Int(x-t, t = 0 .. x), x = y)

Int(y-t, t = 0 .. y)


value(Int(y-t, t = 0 .. y))




However, if you try to evaluate at x = t, the evaluation is delayed until after the integral is evaluated:


eval(Int(x-t, t = 0 .. x), x = t)

eval(Int(x-t, t = 0 .. x), {x = t})



value(eval(Int(x-t, t = 0 .. x), {x = t}))




The eval command knows it shouldn't substitute into an integral when the substitution involves the variable of integration.


However, in the user's example, asking Maple for f(t) is equivalent to substitution directly before the integration is performed, like this:


subs(x = t, Int(x-t, t = 0 .. x))

Int(0, t = 0 .. t)


which of course gives:






Another way to have the two t variables be considered distinct is to explicitly make the integration variable a dummy by declaring it local:


f := proc (x) local t; int(x-t, t = 0 .. x) end proc

Now the ts are treated differently:






Austin Roche

Senior Math Developer





I'd like to clean up my project a bit. In a chapter of a project I made lots of calculations and declared a many (30) variabeles (Table, Numeric, Formula, ..)

Is there a way to remove all variable's except specified one's? (If it is possible I don't want to use an external file to write it to and read it back after a restart)

Is there a way to do a "restart" and preserve only the one's (2) that I need for my next chapter?
Or if not, without a "restart" and remove all variables except specified one's?

Thanks for your help, 

Hi guys.

I have variables that look like C[i,j,k,l], where i,j,k,l can range between 1..3 for example. Is there a simple way to create a pattern-based assumption for something like C[i,j,k,l] = C[j,i,k,l] for all i,j,k,l ?

Kind regards,


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