I am numerically solving a nonlinear system of nine equations. How long can I expect it to take?

I have run it for 30 minutes and it has not solved yet.

Here is the system of equations:

0=Lambda-mu.*S-beta.*(H+C+C1+C2).*(S./N)-tau.*(T+C).*(S./N);

0=tau.*(T+C).*(S./N)-beta.*(H+C+C1+C2).*(T./N)-(mu+mu_T).*T;

0=beta.*(H+C+C1+C2).*(S./N)-tau.*(T+C).*(H./N)-(mu+mu_A).*H;

0=beta.*(H+C+C1+C2).*(T./N)+tau.*(T+C).*(H./N)-(mu+psi.*mu_A+mu_T+lambda_T).*C;

0=lambda_T.*C-(mu+mu_A+rho_1+eta_1).*C1;

0=rho_1.*C1-(mu+mu_A+rho_2+eta_2).*C2;

0=eta_1.*C1-(mu+rho_1+gamma).*CT1;

0=eta_2.*C2-(mu+rho_2+gamma.*(rho_1)./(rho_1+rho_2)).*CT2+(rho_1).*CT1;

0 = N - S - T - H - C - C1 - C2 - CT1 - CT2;

and I have numeric values for Lambda, beta, tau, mu, mu_T, mu_A, rho_1, rho_2, psi, gamma. The only parameters left are eta_1, eta_2.

Thank you.

How is vertical text created in a plot?  It would be similiar to using the labeldirection option set to "vertical", but my text in question will be an annotation within the field of the plot.  A more general question would be how to place rotated text within a plot.    

Hi everyone.

I wrote simple program with several functions. I would like to obtain parallel computing of my functions. I can't understand how to use nodes.

My programm.

Simple_example.mw

When I input

cos(k*Pi) assuming k::odd

The result is -1

but

(-1)^k assuming k::odd

The result is (-1)^k

Why doesn't the second expression work?

AOA... How are you all. I need the answer of the following question.

input in Maple: expand(exp(a+b)+exp(c+b))

output:  exp(a)*exp(b)+exp(c)*exp(b)

and

input in Maple: expand(exp(2a+b)+exp(3c+b))

output:  (exp(a))^2*exp(b)+(exp(c))^3*exp(b)

but i need exp(2a)*exp(b)+exp(3c)*exp(b)

PhD (Scholar)
Department of Mathematics

Say for a complicated function f(x), there are 10 solutions. I want to check for any of the solutions, the matrix R is defined or not.

Is there a way to force execution like the following ones?

seq(1/i,i=0..3);

for i from 0 to 3 do
    1/i;
end do;

I think the problem is that, Maple stops immediately when it's undefined. But the following terms could be defined.

Or is there a way to put this check into "solve"? That's

> solve(f(x),x, "some way of making sure that the solution has to be defined for the matrix R" )

Is there a way to achieve this?

Thanks

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,

woggy

Maple returns the wrong answer to the following very simple double sum:

T:=(x,m)->sum( sum(binomial(m,k+p),k=1..m-p)*x^p,p=0..m-1);

Maple gives zero for all m>0.  However, the correct answer is a non-zero polynomial in x. 

For example, with Maple:

T(x, 3);
                               0

The correct answer is  x^2+4*x+7.

It would be helpful if others can check this double sum in their version of Maple and report results.

I set a physical model for my reseach,

equ1 := x^4-5*x

equ2 := 1/x+x^2+3

x is a function of time t and it meets diff(x(t), t) = equi-equ2.

I want to plot the curve of x(t) varying with time

When I use the following command

DEplot({x(0) = 0, diff(x(t), t) = equi-equ2},x(t), t = 0 .. 20)   it shows: Error, (in DEtools/DEplot) called with too few arguments

Who can tell me what is wrong with my calculation? Thanks

I keep getting an error about the while. It is calling it an invalid if statement.  It may relate to semi colons, but I cannot find any errors myself. Please help.

InterpolIDW2:=proc(n,rwin,mink,p,R,IR)       

local ix,iy,i,j,i0,i1,j0,j1,k;      

local count,wgt,top,bot,hp;      

print(`n=`,n,`rwin=`,rwin,`mink=`,mink,`p=`,p);      

hp:=p/2;        

for iy from 1 to n do      

for ix from 1 to n do           

if (IR(ix,iy)=0) then                

i0:=max(1,ix-rwin);  i1:=min(n,ix+rwin);                

j0:=max(1,iy-rwin);  j1:=min(n,iy+rwin);                 

k:=add(add(IR(i,j),i=i0..i1),j=j0..j1)                                                                

while (k<mink )do                              

if(i0>1) then                                       

i0:= i0-1;                                       

k:= k+ add(IR(i0,j),j=j0..j1)                              

end if;                              

if(i0<1) then                                        

i0:=i0+1;                                        

k:= k+ add(IR(i0,j),j=j0..j1)                              

end if;                              

if(j0>1) then                                        

  j0:=j0-1;                                       

  k:= k+ add(IR(i,j0),i=i0..i1)                         

  end if;                           

 if(j0<1) then                                

 j0:= j0+1;                                         

k:= k+ add(IR(i,j0),i=i0..i1)                             

end if;                         

end do;                  

top:=0;  bot:=0;                

for j from j0 to j1 do                

for i from i0 to i1 do                      

if (IR(i,j)<>0) then                           

wgt:=1/evalf[14](((ix-i)^(2)+(iy-j)^(2))^(hp));                           

top:=top+wgt*R(i,j);                           

bot:=bot+wgt;                      

end if;                

end do;                

end do;                

R(ix,iy):=top/bot;           

end if;      

end do;      

end do;  

end proc:

I'm trying to solve a series of equations and then graph them. I'm trying to solve for the variables involved:

values := solve({eq1, eq2, eq3, eq4, eq5, eq6, eq7, eq8, eq9,

eq10, eq11, eq12, eq13, eq14, eq15, eq16}, {a, b, b, c, d, e, f,

g, h, i, j, k, l, m, n, o, p});

. . . but it gives me this:

Warning, solving for expressions other than names or functions is not recommended. 

values := 

int(int(y, 0 <= y, x^2+y^2+z^2 <= 1));

Error, (in int) integration range or variable must be specified in the second argument, got 0 <= y

int(int(y, y = 0, x^2+y^2+z^2 = 1));

Error, (in int) integration range or variable must be specified in the second argument, got y = 0

A major-league pitcher releases a ball at a point 6 feet above the ground and 58 feet from home plate at a speed of 100 mi/hr ,  

If gravity had no effect, the ball would travel along a line and cross home plate 4 feet off the ground. Find the drop D caused by gravity.                                                                                                                                                      

NB: in this problem the angle alpha is the angle between the horizontal and the direction of the released ball. Since the ball is dropping, alpha will be negative.

Hi every body:

i have a second order ode and will convert to two ode of first order with maple,how do this work???

eq := diff(y(x), x, x)+2*y(x)+y(x)^2 = 0

taylor(1/(1+z^2), z = 1, 4)

The result is 

1/2-(1/2)*z-1+(1/4)*(z-1)^2+O((z-1)^4)

but in fact the result is 

1/2-(1/2)*(z-1)+(1/4)*(z-1)^2+O((z-1)^4)

my Maple is Maple 16,How to solve this problem?