I have a linear problem with 4 variables (p0, p1,p2, p3) and a list of inequality constraints (shown below).  I would like to plot a polyhedral in 3 dimensions (p1,p2, p3 and omitting p0) showing the region that satisfies the inequalities.  That is, something similar to plots[inequal] but in 3d.  Any pointers would be appreciated.

/* Constraints */
+p0 <= 60;
-p0 +p1 >= 4;
-p0 +p2 >= 5;
-p0 +p3 >= -12;
+p0 -p2 >= -33;
+p1 -p2 >= -36;
+p2 <= 67;
-p2 +p3 >= -35;
+p0 -p3 >= 2;
+p1 -p3 >= 0;
+p2 -p3 >= 11;
+p3 <= 57;
+p0 -p1 >= -7;
+p1 <= 43;
-p1 +p2 >= 0;
-p1 +p3 >= -9;

in Maple of a function with respect to a vector that contains product of variables?

I appologize before hand from my abuse of notation. 

Suppose I have a function

f:= x*y*z + 3*x^2*y*z;

and a vector defined as 

v:= <x*z | x^2*z>; #Column vector

and I would like to comput df/dv

So that the result from the Jacobian would be

J=<y , 3*y>; #Row vector

This is a simple example that can be solved by looking, but I would like to know if there is a way in maple to solve something like this. Some of the problems that I find are
1) The variables x*y*z commute i.e. x*y*z=z*x*y=y*z*x=x*z*y
2) And if I apply partial derivatives like  df/(dx*dz) = y+6*x*y and df/(dx*dx*dz) = 6 which is not the result that I desire, because what I want is the partial derivatives with respect to the functions x*z and x^2*z not to the variables x and z.

My application is far bigger than this example that I am posting, this is why I would like to find a way to produce this type of Jacobian. Any suggestion will be highly appreciate it.

for polynomials,

nops(10*x^2)

it return 2, but it is not 1

would like to count some differential equations' terms

for example

b(t)*da(t)/dt + a(t)*b(t) , number of terms is 2

Hello people in mapleprimes,

I have a question.

f1:=1+x:

unapply(f1,x);

returns x->1+x , with maple realizing 1+x is assigned to f1.

But, its short form

x-> f1;

returns

x->f1;

Why does this occur, and how can I have maple return the former result with x->f1 being input?

Thank you in advance for your help.

taro

Hi fellow Maple users,

I'm trying to solve an eigenvalue problem of Ax=wx, where A is a 6 by 6 Hermitian matrix with two parameters x and y. I want to solve it for w and then plot3d it with x and y as unknowns. The way I have been doing is first find the characteristic equation Determinant(A-wI)=0 and then solve it for w, and then plot3d the solutions within a range for x and y. My problem is sometimes solve(Determinant(A-wI)=0,w) would give me the 6 solutions expressed in x and y, but sometimes when the numbers in A are changed it will only give me a Rootof solution with which I cannot plot. I'm wondering if there is a better way to do this. I'm actually not very interested in the symbolic solution of w expressed in x and y, just the plot, so if there is a numerical alternative it's good too.

Thank you in advance!

I have a maple proc for which I would like to find parameters to fit data I have. The proc has an 'if' statement in it, and when I try to use the CurveFitting function 'NonlinearFit' function, I'm getting an error.

Is there a curve fitting function that can be used with procs with 'if' statements in them?

Thanks. 

restart:

f:=exp(-I*Im(s)*(t)); # I is iota, s is a complex number and t is time.

simplify(%);

Thanks

hi

I want help. 

my question is if I have coupled system of x and y variable . how can I find polynomial between these system?

Is there any simple way to extract the feasible range for the variables from solve result ?

For example, when I do solve({x-y = 10, x+y < 100}) I get {x = y + 10, y < 45}

From here, I need -inf<y<45 and -inf<x<55. Is it possible ? (I tried few methods, but it is not working for all cases.)

Why am I getting different results in these two cases ?

Hello maple prime users

I have used the sequence command and series command in Maple before, but seem to have hit a little hurdle with a particular problem.

I want to run the expression:

h(a,b,c):=b!*(a+c)!*sum(F,n=0..c)

   Where F:=(-1)^n*binomial(c,n)*N(a+n):

   Where N(a):=(-1)^n*[evalf(ln(2)) - 1 + 0.5 -1/3 + 1/4 +... + (-1)^a/a]:

I ran a test case using the following code:

restart:
a:=1:
b:=2:
c:=3:
tot:=0:
F:=((-1)^(a+n)/(a+n)):

for n from 0 to c do
      Seq_F2:=(-1)^(a+n):
   
      Seq:=[seq(F,n=0..n)];
      Seq2:=convert(Seq, `+`);

      final:=Seq_F2*(evalf(ln(2))+Seq2);

      SS:=(-1)^n*binomial(c,n)*final;

      S:=(b!*(a+c)!)*SS;
      tot:=tot+S;
od:
tot;

This works for the case where a =1, but will not work for a>1 as in the N(a+n) sequence it misses out the terms in the series for a-1, a-2 etc.... So when a = 2 it misses out the -1 of the sequence and when a = 3 it misses out the -1 and 1/2. Are there any tips on how to overcome this?

Best regards

- Yeti

found differentiated functions with same name but depending on different arguments in the given DE system

restart:

eqn0 := diff(f0(y), y, y, y, y) = 0;

bcs0:=f0(0)=0,(D@@2)(f0)(0)=0,f0(S)=1,D(f0)(S)=0:

dsolve({eqn0,bcs0});

How to fix it?

Thanks

I have the following in a text file.

a:="方程式";

When I read it in command-line maple, I am getting the following error.

on line 1, syntax error, non-ASCII character in unicode file 1:
Error, while reading `123456.txt`

Is it possible to input foreign characters in maple? (I dont want to enter directly in maple worksheet)

Currently I am running a maple engine using a java script and sending equations to the engine.

Thanks in advance.

Dear All,

I am new to maple and trying to write a recursive function with two input variables, but when i execute the statement it shows error "Error, (in B) too many levels of recursion"

Following is the set of instructions which i am trying to execute:

if n=1 then  

B(m,n):=omega(m);  

else  

B(m,n):=sum(omega(j)*B(m-j,n-1),j=1..m-1)

end if

After execution, i try to access B(1,1) or B(2,1), the following error occurs

B(1, 1);
Error, (in B) too many levels of recursion

I'll be grateful, if someone can help me to fix this problem. 

lambdaaaaaa.mwI have calculated lambda(s), now I to substitute  its derivative(1st,2nd) in b[2], b[3]and b[4] in order to calculate the values of constants i.e C1,C2 and C3, plz help