Maple Questions and Posts

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When I right-click on a Matrix, the cursor rotates, but the context menu does not open at all (in Maple 2017, in document mode, in Win 10).
Any suggestions - Anyone else with this problem?

Hi all,

I have an differential equation in terms of the D-operator and am trying to convert it to diff form. Using convert/Diff works fine as long as partially evaluated functions don't appear in the equation. However, I can't figure out how to get the two to cooperate.

For instance, running

D[2](eta)(t,x)+D[2](phi)(t,x,0)+D[2](phi)(t,x,0):
convert(%, Diff);

returns

D[2](eta)(t,x) + Diff(phi(t,x,0),x)

Why is the eta term not converted to diff(eta(t,x),x)?

Thanks a lot!

Hello everyone!

Please help me to resolve following error appeared in PDEs.

I have following system of partial differential equation and tried to solve with numerical method

pde1:=diff(U, t)-(diff(U, x, x))-2*U*(diff(U, x))+diff(U*V, x)

> pde2 := diff(V, t)-(diff(V, x, x))-2*V*(diff(V, x))+diff(U*V, x);
> ics := { U(x, 0) = sin(x),  V(x, 0) = sin(x)};

sol:=pdsolve(pde1,pde2,ics,numeric,time=t, range=1..20)

I am get following error

Error, (in pdsolve) invalid input: `pdsolve/numeric` expects its 2nd argument, IBCs, to be of type {set, list}, but received 0
 

Now, I'm not the professional here, you guys are, since this is how the software has been built to produce this code automatically as i can only assume to be educational purposes for the user, concerning the analytic extension of the factorial on C, the gamma function. 

I feel that doing this is in no way helping or promoting your product, clearly despite the idea indeed having merit, it is not applicable to the extent it has been written into your convert function, and look, show me the mathematics of why it makes sense to have things designed this way. 

 

I am not saying i know anything important or am trying to be insulting, I just feel like this is some kind of joke to be honest, i mean how can for the most part the software be an exceptional in terms of computational power, and then this garbage is thrown at me? yeah just silly.

 


 

product(n/k^2-1/(k*n), k = 1 .. n-3)

-(-1)^(n-2)*GAMMA(-n^2+n-2)*(1/n)^(n-2)*n/(GAMMA(n-2)^2*GAMMA(-n^2+1))

(1)

seq(product(n/k^2-1/(k*n), k = 1 .. n-3), n = 3 .. 10)

1, 15/4, 138/25, 6545/1296, 16215/4802, 2342949/1310720, 7512505/9565938, 29537761/100000000

(2)

seq(convert(-(-1)^(n-2)*GAMMA(-n^2+n-2)*(1/n)^(n-2)*n/(GAMMA(n-2)^2*GAMMA(-n^2+1)), 'factorial'), n = 3 .. 10)

Error, (in GAMMA) numeric exception: division by zero

 

Um there is no gamma it was converted to a factorial.....? but ok....

convert(-(-1)^(n-2)*GAMMA(-n^2+n-2)*(1/n)^(n-2)*n/(GAMMA(n-2)^2*GAMMA(-n^2+1)), 'factorial')

-(-1)^(n-2)*factorial(-n^2+n-3)*(1/n)^(n-2)*n/(factorial(n-3)^2*factorial(-n^2))

(3)

seq(-(-1)^(n-2)*factorial(-n^2+n-3)*(1/n)^(n-2)*n/(factorial(n-3)^2*factorial(n^2)), n = 100 .. 100)

Error, numeric exception: division by zero

 

``


 

Download REALLY_REALLY.mw

Just like the title described, I have encountered an error when I use the command "expand". Actually, I just follow the example, but it doesn't work. Please help me or tell me how can I solve it in other commands.


restart;
alias(epsilon = e, omega = w, omega[0] = w0, t[1] = t1, t[2] = t2); e := proc (t1, t2) options operator, arrow; e end proc; w0 := proc (t1, t2) options operator, arrow; w0 end proc; a := proc (t1, t2) options operator, arrow; a end proc; f := proc (t1, t2) options operator, arrow; f end proc; mu := proc (t1, t2) options operator, arrow; mu end proc;
ode := (D@@2)(u)+2*mu*e*D(u)+w0^2*u+e*w0^2*u^3-e*f*cos(omega*t) = 0;
                                               2  
     @@(D, 2)(u) + 2 mu epsilon D(u) + omega[0]  u

                          2  3                             
        + epsilon omega[0]  u  - epsilon f cos(omega t) = 0
e_oredr := 1;
ode := simplify(subs(D = sum('e^(i-1)*D[i]', 'i' = 1 .. e_oredr+1), ode), {e^(e_oredr+1) = 0});
 / 3         2                                                 
 \u  omega[0]  + 2 (epsilon D[2] + D[1])(u) mu - cos(omega t) f

                  \                   2                   
    + 2 D[1, 2](u)/ epsilon + omega[0]  u + D[1, 1](u) = 0
simplify(collect(%, e), {e^(e_oredr+1) = 0});

u := sum('v[i]*e^i', 'i' = 0 .. e_oredr);
                      epsilon v[1] + v[0]
ode := simplify(collect(ode, e), {e^2 = 0});
for i from 0 to e_oredr do eq[i] := coeff(lhs(ode), e, i) = 0 end do;
                       2                         
               omega[0]  v[0] + D[1, 1](v[0]) = 0
       3         2           2                       
   v[0]  omega[0]  + omega[0]  v[1] + 2 D[1](v[0]) mu

      - cos(omega t) f + 2 D[1, 2](v[0]) + D[1, 1](v[1]) = 0
remove(has, lhs(eq[1]), cos); convert(%(t1, t2), diff);
eq[1] := %-convert(f*cos(sigma*t2+t1*w0), 'exp');

v[0] := A(t2)*cos(w0*t1+B(t2)); convert(%, 'exp'); v[0] := unapply(%, t1, t2);
                         /1                             
       (t1, t2) -> A(t2) |- exp(I (omega[0] t1 + B(t2)))
                         \2                             

            1                              \
          + - exp(-I (omega[0] t1 + B(t2)))|
            2                              /

expand(eq[1]);
Error, (in property/ConvertProperty) invalid input: PropRange uses a 2nd argument, b, which is missing
collect(%, exp(I*w0*t1));
Error, (in collect) invalid 1st argument proc (t1, t2) options operator, arrow; A(t2)*((1/2)*exp(I*(w0*t1+B(t2)))+(1/2)*exp(-I*(w0*t1+B(t2)))) end proc
coeff(%, exp(I*w0*t1));
map(proc (x) options operator, arrow; x*exp(-I*B(t2)) end proc, %);
combine(%, 'exp');
subs(I*B(t2) = I*sigma*t2-I*C(t2), B(t2) = sigma*t2-C(t2), %);
conds := combine(%, 'exp');
                               0

 

With this feature, it requires the worksheet from which to import a result from executing it from the worksheet with the Run worksheet command to have section titles as Input  and Calculation respectively.

 

This is a really helpful feature, but what i need is to "fetch" the content from a number of worksheets in a folder from a specified particular section name, for a number of different section names.

Hi everyone,
I was wondering how to create a function, as we create in MatLab, in Maple. Here is an example of MatLab function, that I should convert to Maple:

function Y=fsin(delta,b,n)

if n==0
    Y=1/(1+b^2);
end
if n==1
    Y=atan(1/b);
end
if n==2
    Y=1+log(b^2 + 1)/2-b*atan(1/b);
end
if n==3
    Y=0.5*(2*delta-3*b-2*b*log(b^2 + 1)/2+atan(1/b)*(b^2-1));
end
if n==4
    Y=(1/36)*(18*delta^2-36*delta*b+33*b^2-11+6*log(b^2 + 1)/2*(3*b^2-1)+6*b*atan(1/b)*(3-b^2));
end
if n==5
    Y=(1/72)*(24*delta^3-36*delta^2*b+12*delta*(3*b^2-1)+25*b-25*b^3+12*b*log(b^2 + 1)/2*(1-b^2)+3*atan(1/b)*...
        (1-6*b^2+b^4));
end
if n==6
    
    Y=(1/7200)*(1800*delta^4-2400*delta^2*b+600*delta^2*(3*b^2-1)+1200*b*delta*(1-b^2)+685*b^4-1370*b^2+137+...
        60*log(b^2 + 1)/2*(5*b^4-10*b^2+1)+60*b*atan(1/b)*(-5+10*b^2-b^4));
end
if n==7
    Y=(1/21600)*(4320*delta^5-5400*delta^4*b+1200*delta^3*(3*b^2-1)+...
        1800*delta^2*b*(1-b^2)+180*delta*(5*b^4-10*b^2+1)-441*b+1470*b^3-441*b^5+...
        60*b*log(b^2 + 1)/2*(-3*b^4+10*b^2-3)+30*atan(1/b)*(-1+15*b^2-15*b^4+b^6));
end
end

  Thank you,  

In Maple 2018 help written:

The interpolation methods available in the Interpolation package all work as follows. First, the user calls one of the commands in the package, submitting the input points and the values at these points. This returns an object encapsulating all the data and options submitted. This object can then be used like a normal mathematical function, e.g. for plotting, integration, or just to evaluate at a given point.

The Interpolation[Interpolate] command was introduced in Maple 2018
 

My test example:

with(Interpolation):

points := [seq(x, x = 0 .. 10, 1)]; data := [seq(sqrt(1.+x^2), x = 0 .. 10, 1)];

f := Interpolate(points, data);

f(1); # OK works :).

int(f(x), x = 0 .. 1); # Not working ?

int(f(x), x = 0 .. 1,numeric); # Not working ?

eval(diff(f(x), x), x = 2);# Not working ?

plot(f(x), x = 0 .. 10);#  OK works :)

plot([f(x), diff(f(x), x)], x = 0 .. 10);# Not working ?

plot([f, diff(f, x)], 0 .. 10);# Only a half  working ?

 

Thanks.


 

 

Hi everybody,

I am a newbie in Maple. Could you please help me to convert the following short code from Matlab to Maple: 

I=0.0;

for i1=1:3

  for i2=1:3

    for i3=1:3

      for i4=1:3

        if i1==i2 && i2==i3 && i3=i4

        I(i1,i2,i3,i4)=1.0;

        else

        I(i1,i2,i3,i4)=0.0;

        end

      end

    end

  end

end

Thank you,

Hi,

I would like to plot a stem plot of a function and its Fourier transform but I'm not too sure how to. I have tried using different packages like DiscreteTransforms, DynamicSystems and SignalProcessing but can't seem to get it to work. Any advice is appreciated.

Thanks

Substituting variables for numbers doesn't always work in some situations.  For example.

a:=sqrt(6)/6
                            

subs(6=b,a)
                        

 

 

sign doesn't work with square roots

expr := sqrt(3)*x^2*y^4-2*x*y^5+x
                                              

sign(expr)

sign(sqrt(3))

 

 

Hi,

So I need an example of how the discrete fourier transform works, and I would like to do this using Maple but I can't figure out how to plot a discrete function. I have attached an example from wikipedia which is what I would like. It is the function on the right of the image. I have tried plotting a vector but then I can't seem to plot this. Let me know if the question isn't quite clear.

Thanks

 

Hi

When i try to simplify this, maple doesn't simplify to the final step. 

I hope anyone can help me. 

Laura

 

 

I want ot replace the free variable introduced by the BackwardsSubstitution procedure with a number. But though the variable looks like x1 I think it must be something else.

problem.maple

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