eq1 := diff(x(t), t) = x(K[1]-x(t))-p*x(t-tau[1])*y(t); eq2 := diff(y(t), t) = y(K[2]-x(t))-q*y(t-tau[2])*x(t);
(x*, y*):= (p*K[2]-k[1])/(p*q-1), (q*K[1]-k[2])/(p*q-1);

where, k_1, k_2, p, q, tau_1, tau_2 are positive constants

I get this error when typing a sigma symbol with some subscripts.

Is there anyway to get rid of it?

If mapleflow doesn't allow typing in this way, how can I type it in an unexcutable Math format like document mode in Maple?

Hi everyone! I'd really appreciate if I could get pointed in the right direction as I am a brand new maple user.

So im trying to solve this constrainted optimization problem (See picture) using Maple symbollically. I believe I should have a closed form solution given I can substitute the one constraint into the objective function. Specifically closed form solutions for the three phi variables.

Can someone point me in the right direction as to how I should go about this? I've already taken first order conditions and tried to using the solve() function to no avail, realizing my sytem of equations weren't linear );. 

I have problems with tasks.

If you have some usefull commands, you select them all, right-click and select 'create task'. You now get a button in the 'task'-pane in Maple you can use whenever you need to insert these commands- - - brilliant!!

But now I want to modify these tasks and delete the ones I don't use anymore or the ones I made by mistake.

Right-click on the task does nothing.

Selecting 'tools' from the menu and then 'tasks' allows me to see the tasks I have made, but not to modify them or delete them

How do I modify or delete a task??

/Rasmus Post

how we can merge multiple plots in single graph in maple ???

Hi! do you know any effective method to count area under this function given by dataset points? (I counted this by approximation by trapezes)

Edit: PolyFit is ok the best what I have done

Edit2: triangulation is the best (just add all triangles)

How to rectify this error

k := 0;

for k[1] from 0 to k do Y[k[1]+3] := solve(sum(sum(factorial(k[1]+3)*(-1)^((k-k[1]-1)*(1/2))*Y(k[1]+3)/(factorial(k[1])*factorial(k-k[1])), k[1] = 0 .. k), k = 0 .. infinity)-(sum(1/4*((-1)^((1/2)*k)/factorial(k)-(3^k)(-1)^((1/2)*k)/factorial(k)), k = 0 .. infinity))-(sum(factorial(k[1]+2)*(-1)^((k-k[1])*(1/2))*Y(k[1]+2)/(factorial(k[1])*factorial(k-k[factorial(1)])), k[1] = 0 .. k)), Y[k[1]+3]) end do;
                               0
Error, (in sum) summation variable previously assigned, second argument evaluates to 0 = 0 .. k

Hi! Do you know how to divide this array from .txt data to take separately these numbers? (I have over one thousands of these so I don't want to rewrite)

PS this is 1x1 I want to make 1x8

["0,00244140625;8,07751097960625;-3,555908203125E-05;0,002166748046875;1;1;0,0056941700604248;-0,0101856454842773;100 µA"]

Maple apparently has managed to destroy the last working piece of code in the Units package in the 2022 release.

This code is working in Maple 2021, but not in 2022 anymore.

Download UnitsSimple_alpha.mw

Dear all

I tried to use the command Secant to solve a nonlinear system of equations, In the following, example of two simple equations, how can I use Secant to solve the problem

secant_for_system.mw

Thank you 

Hy

How I solved it accurately,and remove "'rootoff

eq1 := alpha + beta*r[c] - d*n[c] - Upsilon*n[c]*(n[r] + r[c]) - n[r]*(alpha - d*n[c] - b*(n[r] + r[c]));
q2 := `eϒ`*n[c]*(n[r] + r[c]) - mu*n[r] + d*n[c]*n[r] + b*n[c]*n[r] - alpha*n[r];
eq3 := b*n[c]*n[r] + d*n[c]*n[r] - alpha*n[r] - beta*r[c] + mu*n[r];
 eq1 := alpha + beta r[c] - d n[c] - Upsilon n[c] (n[r] + r[c])

    - n[r] (alpha - d n[c] - b (n[r] + r[c]))
   eq2 := Upsilon n[c] (n[r] + r[c]) - mu n[r] + d n[c] n[r]

      + b n[c] n[r] - alpha n[r]
   eq3 := b n[c] n[r] + d n[c] n[r] - alpha n[r] - beta r[c]

      + mu n[r]
solve({eq1, eq2, eq3}, {n[c], n[r], r[c]});
 /       alpha                    \    /             /          
{ n[c] = -----, n[r] = 0, r[c] = 0 }, { n[c] = RootOf\(Upsilon b
 \         d                      /    \                        

                  2                                              
   + Upsilon d) _Z  + (-Upsilon alpha + Upsilon beta + Upsilon mu

                                               \               //
   + b beta + beta d) _Z - alpha beta - mu beta/, n[r] = RootOf\\

   2           2                         \   2   /
  b  beta + 2 b  mu + b beta d + 2 b d mu/ _Z  + \
       /                          2                  
-RootOf\(Upsilon b + Upsilon d) _Z  + (-Upsilon alpha

   + Upsilon beta + Upsilon mu + b beta + beta d) _Z - alpha beta

            \                           /                        
   - mu beta/ Upsilon alpha b - 2 RootOf\(Upsilon b + Upsilon d) 

    2                                                       
  _Z  + (-Upsilon alpha + Upsilon beta + Upsilon mu + b beta

                                      \                          /
   + beta d) _Z - alpha beta - mu beta/ Upsilon b beta - 2 RootOf\

                            2                                 
  (Upsilon b + Upsilon d) _Z  + (-Upsilon alpha + Upsilon beta

                                                            \ 
   + Upsilon mu + b beta + beta d) _Z - alpha beta - mu beta/ 

                         /                          2    
  Upsilon b mu - 3 RootOf\(Upsilon b + Upsilon d) _Z  + (
-Upsilon alpha + Upsilon beta + Upsilon mu + b beta + beta d) _Z

                         \                          /          
   - alpha beta - mu beta/ Upsilon beta d - 3 RootOf\(Upsilon b

                  2                                              
   + Upsilon d) _Z  + (-Upsilon alpha + Upsilon beta + Upsilon mu

                                               \             
   + b beta + beta d) _Z - alpha beta - mu beta/ Upsilon d mu

                                             \            /
   - alpha b beta + 2 b beta mu + 3 beta d mu/ _Z + RootOf\

                            2                                 
  (Upsilon b + Upsilon d) _Z  + (-Upsilon alpha + Upsilon beta

                                                            \ 
   + Upsilon mu + b beta + beta d) _Z - alpha beta - mu beta/ 

                          /                          2    
  Upsilon alpha b + RootOf\(Upsilon b + Upsilon d) _Z  + (
-Upsilon alpha + Upsilon beta + Upsilon mu + b beta + beta d) _Z

                         \                        /          
   - alpha beta - mu beta/ Upsilon beta d + RootOf\(Upsilon b

                  2                                              
   + Upsilon d) _Z  + (-Upsilon alpha + Upsilon beta + Upsilon mu

                                               \             
   + b beta + beta d) _Z - alpha beta - mu beta/ Upsilon d mu

                             \          1   /      // 2     
   + alpha b beta - beta d mu/, r[c] = ---- \RootOf\\b  beta
                                       beta                 

        2                         \   2   /
   + 2 b  mu + b beta d + 2 b d mu/ _Z  + \
       /                          2                  
-RootOf\(Upsilon b + Upsilon d) _Z  + (-Upsilon alpha

   + Upsilon beta + Upsilon mu + b beta + beta d) _Z - alpha beta

            \                           /                        
   - mu beta/ Upsilon alpha b - 2 RootOf\(Upsilon b + Upsilon d) 

    2                                                       
  _Z  + (-Upsilon alpha + Upsilon beta + Upsilon mu + b beta

                                      \                          /
   + beta d) _Z - alpha beta - mu beta/ Upsilon b beta - 2 RootOf\

                            2                                 
  (Upsilon b + Upsilon d) _Z  + (-Upsilon alpha + Upsilon beta

                                                            \ 
   + Upsilon mu + b beta + beta d) _Z - alpha beta - mu beta/ 

                         /                          2    
  Upsilon b mu - 3 RootOf\(Upsilon b + Upsilon d) _Z  + (
-Upsilon alpha + Upsilon beta + Upsilon mu + b beta + beta d) _Z

                         \                          /          
   - alpha beta - mu beta/ Upsilon beta d - 3 RootOf\(Upsilon b

                  2                                              
   + Upsilon d) _Z  + (-Upsilon alpha + Upsilon beta + Upsilon mu

                                               \             
   + b beta + beta d) _Z - alpha beta - mu beta/ Upsilon d mu

                                             \            /
   - alpha b beta + 2 b beta mu + 3 beta d mu/ _Z + RootOf\

                            2                                 
  (Upsilon b + Upsilon d) _Z  + (-Upsilon alpha + Upsilon beta

                                                            \ 
   + Upsilon mu + b beta + beta d) _Z - alpha beta - mu beta/ 

                          /                          2    
  Upsilon alpha b + RootOf\(Upsilon b + Upsilon d) _Z  + (
-Upsilon alpha + Upsilon beta + Upsilon mu + b beta + beta d) _Z

                         \                        /          
   - alpha beta - mu beta/ Upsilon beta d + RootOf\(Upsilon b

                  2                                              
   + Upsilon d) _Z  + (-Upsilon alpha + Upsilon beta + Upsilon mu

                                               \             
   + b beta + beta d) _Z - alpha beta - mu beta/ Upsilon d mu

                             \ /      /                        
   + alpha b beta - beta d mu/ \RootOf\(Upsilon b + Upsilon d) 

    2                                                       
  _Z  + (-Upsilon alpha + Upsilon beta + Upsilon mu + b beta

                                      \           /          
   + beta d) _Z - alpha beta - mu beta/ b + RootOf\(Upsilon b

                  2                                              
   + Upsilon d) _Z  + (-Upsilon alpha + Upsilon beta + Upsilon mu

                                               \               \\
   + b beta + beta d) _Z - alpha beta - mu beta/ d - alpha + mu//

  \ 
   }
  / 
 

Dear all

I have  a funciton f(x,y) 
I compute the critical point, maple gives me three different points, denoted in the code tmin 

from these points how can I fix one  one of them that  give me the min( f(x)) 

code.mw

thank you for any help

H all expert

first this Expression 

ni := diff(Q(x, t), t)+a*Q*(x, t)*(diff(Q(x, t), x))+b*(diff(Q(x, t), t$3))+d*(diff(Q(x, t), t$5)) = 0

then I want to solve  diff(Q(x, t), t$5) 

diff(Q(x, t), t$5) = solve(ni, diff(Q(x, t), t$5))#eq2

p (x, t) :=H1(t)*Q(x*H2(t), H3(t)) #assumption 

k := diff(p(x, t), t)+a*p(x, t)*(diff(p(x, t), x))+diff(p(x, t), t$3)+d*(diff(p(x, t), t$5))+c*p(x, t) #eq3

r := subs(diff(Q(x, t), t$5), k) #subs eq2 in eq3

i recived error

SUBS1.mw

I need some calculations in a noncommutative ring - specifically, I need to rewrite/simplify some algebraic expressions in those variables.  My variables need to be indexed by integers - for example, I need variables A[n], B[n], and C[n], where n is an arbitrary integer.  These variables should not commute.  My approach to doing this so far has been to use quantumoperators:

There are some commutator relations that need to be imposed.  For example, suppose we have 

Commutator(A[m], B[n]) = C[m+n].

I can impose these commutator relations using 

That part is ok.   But I would also like to subsitute certain algebraic expressions in these variables.  For example, suppose I would like to substitute A[2]*B[3] = 5. It seems I should be able to do so using subs or algsubs. This works on very simple expressions: for example, I get 

 as I would expect.  But the following does not work: 

But I should get output 5C₄+ C₃.  This problem also persists if I use subs in stead of  algsubs.  It does not appear if I use 'standard' commuting variables.  

I want to apply rk-2 for the following system of odes. I want to know what is process of rk-2 method maple used? Is it possible that we can see the complete process maple used?

Download Question.mw