acer

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These are answers submitted by acer

If you insert a Plot component whose id is "Plot0" and a Slider component whose id is "Slider0" then you can tie them together in the following simple way:

You don't need to change any of the Action code or Properties of the Plot component. Just leave the inserted Plot component alone. Instead, change the "Value Changed Action" of the Slider component to be just this,

  use DocumentTools in 
    SetProperty("Plot0", value, plot(GetProperty("Slider0", value)*x^2,
                                     x=-10..10, view=0..500));
  end use; 

Of course, you can alter the range used for the `view` option, as desired.

That should result in a worksheet in which someone can use the Slider immediately upon launch or re-opening.

On the other hand, issuing the following command in Maple 17 should also make a worksheet that can be used either immediately or after closing and re-opening.

Explore(plot(a*x^2,x=-10..10,view=0..1000),
        parameters=[a=0.0..10.0], newsheet, showbanner=false);

Also, the table which contains all the embedded components inserted via an `Explore` call (with or without the `newsheet` option) could be copied & pasted even within the current open worksheet. Any originally inserted components and any `Explore` call which created them could be removed, and then the copy&pasted instance should still run ok.

Note that, if the thing being explored (be it function call or expression) depends on some earlier assignments in the session then those may have to be reproduced when re-opening the worksheet. The Startup Region can provide a way to make this automatic, in such cases.

acer

With luck I entered it all correctly.

restart:

dsys:=diff(x(t),t)=0.2*x(t)*(1-0.5*x(t))-(1.5*x(t)*y(t))/(1+0.116*x(t)),
      diff(y(t),t)=(1.3*x(t)*y(t))/(1+0.1*x(t))-0.8*y(t):
ics:=x(0)=1,y(0)=2:

P1:=DEtools[DEplot]({dsys},[x(t),y(t)],t=0..50,x=-1..3,y=-1..3,
                    [[ics]],linecolor=green,maxfun=10^5,arrows=small):

F:=proc(par)
  DEtools[DEplot]({dsys},[x(t),y(t)],t=0..50,x=-1..3,y=-1..3,
                  [[ics]],linecolor=blue,maxfun=10^5,arrows=small,
                  method=classical[foreuler],stepsize=par);
end proc:

plots:-display(P1,F(0.005));

Explore(plots:-display(P1,F(stepsize)),
        parameters=[stepsize=0.005..1.0]);

acer

Click the "New" tab beside "Popular". Then click on the rightmost of the 5 buttons at the bottom, the one which looks like a blue circle with a white downward pointing triangle in it. Pressing that will scroll down the full list by a "page" (10 items, say).

acer

One sensible appraoch, as Carl has shown, is to generate a sequence of `plot` calls, where each one sets its own color. And then `plots:-display` can handle the title. This could serve you well, if you also wanted to have differing linestyles, etc.

Another approach, which I believe works for providing multiple curve colors for the given problem, is to make just a single call to `plot` command using its own specification for handling multiple curves. This provides the immediate support of the palette functionality of plots:-setcolors to get differing colors for multiple curves using either system color palettes or user-defined lists as palette.

The final line in the procedure could be, (pasted here in plaintext 1D Maple notation)

  plot([seq]([seq]([T, eval(X[c], Sol[T])],
                   T = 600 .. 1200, 50),
             c = [CH4, CO2, H2O, H2, CO]),
        title='Frações*molares*dos*compostos*por*variação*de*temperatura')

acer

If the `m~` in your `eqnl1x` is an assumed local then you could try, say,

  globeqnl1x := convert(eqnl1x, `global`):

# and then

  eval(globeqnl1x, [`m~`=1]);

# or

  subs( `m~`=1, globeqnl1x );

Or you could try and pick out the locals of `eqnl1x` using the `indets` command, and figure out which one equals the local `m~` (by testing for equality with global :-`m~` after conversion to `global`, perhaps) and assign that to a new name to use instead for the substitution process. Ie,something perhaps like,

usem := select(u->convert(u,`global`)=:-`m~`,indets(eqnl1x,`local`))[1];
subs( usem=1, eqnl1x );

acer

For question 1, you have forgotten to load DocumentTools, or to call it as DocumentTools:-SetProperty, in the Startup Code region.

For question 2, add the option,

  refresh=true

to the SetProperty command. Ie, change,

   SetProperty(Button1, enabled, false);

to

   SetProperty(Button1, enabled, false, refresh=true);

acer

In 17.02 I see the described behaviour.

If I put another static single plot into the Plot0 component then it again needs two presses of the Button in order to start the animation playing. The same holds if I recompute `dis`.

But if I replace that call to DocumentTools:-Do with,

   SetProperty(Plot0, value, dis, refresh=true);

then it seems to always start playing on the first Button press.

acer

If your complaint is that not all the twenty-seven entries in the result themselves have three entries then the error is yours, not Maple's. You are using sets with {} while it seems that you need lists [] instead. With sets duplicates will not appear (and the triples are also sorted, btw).

seq([round(x11[k]), round(y11[k]), round(z11[k])], k = 1 .. 27);

acer

restart:                     

ineq:=(3-x-sqrt(5-x^2))/(cos((2*x-7)/4)-cos((x-5)/4))>=0:          

convert(simplify([solve(ineq)]),tan);                              

                                                           1/2
               [RealRange(1, Open(2)), RealRange(Open(2), 5   )]

acer

The `subs` command offers simultaneous substitution.

f:= x1 * x2 * x3^4;

                                   4
                           x1 x2 x3 

subs({x1=x3,x3=x1},f);

                                   4
                           x3 x2 x1 

You can compare that against the sequential substitution,

subs(x1=x3,x3=x1,f);

                               5   
                             x1  x2

acer

This is Maple 17.02 64bit on Windows 7 Pro.

restart:

ee:=sin(Pi*(x+1)/(4*x^2-4*x+2))=cos(Pi*(x-2)/(4*x^2-4*x+2)):

S:=[solve(convert(convert(ee,cos),expln),x)]:

seq(print(s), s in S);

                        /3        1       (1/2)\       
                      I |- I Pi + - I Pi 5     | + 2 Pi
                        \2        2            /       
                      ---------------------------------
                                     Pi      
          
                        /3        1       (1/2)\       
                      I |- I Pi - - I Pi 5     | + 2 Pi
                        \2        2            /       
                      ---------------------------------
                                     Pi    
            
                                      1

                                      1

evalf(S);

                    [-0.6180339884, 1.618033988, 1., 1.]

simplify(S);

                     [1   1  (1/2)  1   1  (1/2)      ]
                     [- - - 5     , - + - 5     , 1, 1]
                     [2   2         2   2             ]

[seq(simplify(eval(ee,x=s)), s=S)];

     [    /1     / (1/2)    \\      /1     /     (1/2)\\  
     [-sin|-- Pi \5      - 3/| = cos|-- Pi \3 + 5     /|, 
     [    \12                /      \12                /  

          /1     /     (1/2)\\      /1     / (1/2)    \\              ]
       sin|-- Pi \3 + 5     /| = cos|-- Pi \5      - 3/|, 0 = 0, 0 = 0]
          \12                /      \12                /              ]

map((lhs-rhs)@expand,%);

                                [0, 0, 0, 0]

[solve(convert(convert(ee,cos),expln),x,allsolutions)];

                 [    /             1        1     (1/2)\   
                 [2 I |-I Pi _Z5~ - - I Pi + - (%1)     |   
                 [    \             4        4          /   
                 [---------------------------------------,  
                 [            Pi (4 _Z5~ + 1)               
                 [                                          
                                                            
                       /             1        1     (1/2)\  
                   2 I |-I Pi _Z5~ - - I Pi - - (%1)     |  
                       \             4        4          /  
                   ---------------------------------------, 
                               Pi (4 _Z5~ + 1)              
                                                            
                                                            
                     /              3        3     (1/2)\   
                   2 |3 I Pi _Z4~ + - I Pi + - (%2)     |   
                     \              2        2          /   
                   --------------------------------------,  
                                           (1/2)            
                            3 I Pi + 6 (%2)                 
                                                            
                     /              3        3     (1/2)\]  
                   2 |3 I Pi _Z4~ + - I Pi - - (%2)     |]  
                     \              2        2          /]  
                   --------------------------------------]  
                                           (1/2)         ]  
                            3 I Pi - 6 (%2)              ]  
                                                            
                                                            
                            2     2        2            2   
                 %1 := 16 Pi  _Z5~  - 16 Pi  _Z5~ - 5 Pi    
                           2     2       2                  
                 %2 := 4 Pi  _Z4~  + 2 Pi  _Z4~             

Amusingly,

solve(convert(convert(ee,sin),expln),x); # whoops
Error, (in Engine:-Dispatch) not implemented yet: 5

acer

Three popular choices for trying to find all roots in a finite real range are to use Student:-Calculus1:-Roots (which calls fsolve repeatedly with its `avoid` option), RootFinding:-Analytic, or to repeatedly call RootFinding:-NextZero.

Below, the original problem is used, but for a larger domain of x=0 to x=100.

Note that, with default settings at least, the fsolve approach finds fewer solutions. I would guess that for a large enough right end-point the extreme steepness of the mathematical function between the upper roots would cause `NextZero` to falter as well. It may not be an issue for this particular problem, but the RootFinding:-Analytic approach can messy if there are roots very close to the real line, since it can be difficult to distinguish which are valid but unwanted nonreal solutions and which are wanted purely real solutions which just happen to have been approximated with very small but nonzero imaginary components due to roundoff error.

restart:

findroots:=proc(expr,a,b,{guard::posint:=5,maxtries::posint:=50})
local F,x,sols,i,res,start,t;
   x:=indets(expr,name) minus {constants};
   if nops(x)>1 then error "too many indeterminates"; end if;
   F:=subs(__F=unapply(expr,x[1]),__G=guard,proc(t)
      Digits:=Digits+__G;
      __F(t);
   end proc);
   sols,i,start:=table([]),0,a;
   to maxtries do
      i:=i+1;
      res:=RootFinding:-NextZero(F,start,
                                 'maxdistance'=b-start);
      if type(res,numeric) then
         sols[i]:=fnormal(res);
         if sols[i]=sols[i-1] then
            start:=sols[i]+1.0*10^(-Digits);
            i:=i-1;
         else
            start:=sols[i];
         end if;
      else
         break;
      end if;
   end do;
   op({entries(sols,'nolist')});
end proc:

CodeTools:-Usage( findroots(exp(x)*cos(x)+1, 0, 100) );
memory used=0.55MiB, alloc change=0 bytes, cpu time=47.00ms, real time=33.00ms

1.746139530, 4.703323759, 7.854369686, 10.99555751, 14.13716766, 17.27875956, 

  20.42035224, 23.56194490, 26.70353755, 29.84513020, 32.98672286, 

  36.12831551, 39.26990816, 42.41150082, 45.55309347, 48.69468613, 

  51.83627878, 54.97787143, 58.11946409, 61.26105674, 64.40264939, 

  67.54424205, 70.68583470, 73.82742735, 76.96902001, 80.11061266, 

  83.25220532, 86.39379797, 89.53539062, 92.67698328, 95.81857593, 98.96016858

nops({%});
                                     32
restart:

CodeTools:-Usage( RootFinding[Analytic](exp(x)*cos(x)+1=0, re=0..100, im=-1..1) );
memory used=23.34MiB, alloc change=24.00MiB, cpu time=343.00ms, real time=341.00ms

 48.6946861306418, 45.5530934770530, 42.4115008234622, 39.2699081698730, 

   29.8451302091029, 73.8274273593600, 70.6858347057710, 67.5442420521805, 

   64.4026493985910, 61.2610567450010, 86.3937979737195, 83.2522053201305, 

   80.1106126665395, 76.9690200129500, 92.6769832808990, 89.5353906273097, 

   95.8185759344885, 98.9601685880785, 54.9778714378215, 51.8362787842320, 

   58.1194640914110, 23.5619449018649, 10.9955575115013, 20.4203522496875, 

   32.9867228626928, 26.7035375555158, 36.1283155162826, 7.85436968657417, 

   4.70332375945224, 14.1371676661008, 17.2787595634161, 1.74613953040801


nops([%]);
                                     32

restart:

asolve := proc(ex, var :: name, rng :: range, {avoid :: set := {}})
local avoids,ends,i,sols;
    sols := [fsolve](ex, var, rng, _options['avoid']);
    if sols = [] or not sols :: 'list(numeric)' then
        return avoid;
    else
        ends := [lhs(rng), op(sort(sols)), rhs(rng)]; # sols already sorted?
        avoids := {op(avoid),map2(`=`,var,sols)[]};
        {seq(op(thisproc(ex,var,ends[i-1]..ends[i], ':-avoid' = avoids))
             , i = 2 .. nops(ends))};
    end if;
end proc:

CodeTools:-Usage( asolve(exp(x)*cos(x)+1, x, 0..100) );
memory used=89.20MiB, alloc change=28.00MiB, cpu time=1.36s, real time=1.37s

   {x = 1.746139530, x = 4.703323759, x = 7.854369687, x = 10.99555751, 

     x = 14.13716767, x = 17.27875956, x = 20.42035225, x = 23.56194490, 

     x = 26.70353756, x = 29.84513021, x = 32.98672286, x = 36.12831552, 

     x = 39.26990817, x = 42.41150082, x = 45.55309348, x = 48.69468613, 

     x = 51.83627878}

nops(%);
                                     17
restart:
CodeTools:-Usage( Student:-Calculus1:-Roots(exp(x)*cos(x)+1,x=0..100,numeric) );
memory used=87.17MiB, alloc change=28.00MiB, cpu time=1.36s, real time=1.36s

[1.746139530, 4.703323759, 7.854369687, 10.99555751, 14.13716767, 17.27875956, 

  20.42035225, 23.56194490, 26.70353756, 29.84513021, 32.98672286, 

  36.12831552, 39.26990817, 42.41150082, 45.55309348, 48.69468613, 51.83627878

  ]

nops(%);
                                     17

acer

You could try using the Basis command instead.

with(LinearAlgebra):

A:=Matrix([[-3,6,-1,1-7],[1,-2,2,3,-1],[2,-4,5,8,-4]]);

                               [-3   6  -1  -6   0]
                               [                  ]
                          A := [ 1  -2   2   3  -1]
                               [                  ]
                               [ 2  -4   5   8  -4]

Basis({seq(A[..,i],i=1..ColumnDimension(A))});

                             /[-3]  [-1]  [-6]\ 
                             |[  ]  [  ]  [  ]| 
                            < [ 1], [ 2], [ 3] >
                             |[  ]  [  ]  [  ]| 
                             \[ 2]  [ 5]  [ 8]/ 

Use the menu item Edit -> Split or Join.

It has the keyboard shortcut of F3 (on MS-Windows at least).

acer

Did you intend y(x)^M instead of y^M?

restart:
eq1:=diff(y(x),x$2)+2/x*(diff(y(x),x))+y(x)^M=0:
ic:=y(0)=a,D(y)(0)=0:
p:=dsolve(eval({eq1,ic},[a=1,M=3]), y(x),numeric,output=listprocedure):
Y:=eval(y(x),p):
plot(Y,0..500);
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