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

here my code . iam trying to generate a binomial sample but there is some error occure please help

This should be a simple problem, but I am having trouble resolving a contradiction in integral evaluation that is included in the results below.  Instead of butting my head further perhaps someone can point out my probable error.

You will see in both cases I have a triangle signal with a slope of (-1).  However in the 2nd case I have linked the period T to the slope parameter alpha.  If I assign alpha=1 then the results of the 2 integrals should = 1/4, but the 2nd one does not.

Appreciate any feedback.

Download integral_contradiction.mw

Hi,

This is my first question here! 

I want to show weird things that can happen in numerical analysis. The example I use is the sum from i=1 to infinity of (1/i) (the harmonic series). In theory this series diverge but in practice it could converge. 

I would want all the calculations to use floating point arithmetic with small mantissa (for instance m=1,2,3)). But the problem is I don't know how to fix mantissa in maple... I have the following fonction: 

g := n -> evalf[m](sum(evalf[m](1/i),i=1..m))

but evalf just show significant digit without changing the mantissa.... 

I hope my question is clear! Thanks for your help! 

Hi, I a have a question, if you can help me I would be pleased
 

Here is a problem:

for i from 1 to 4 do
 if A[i,i]=0 then break
 else
  for l from i to 4 do
   A[i,l]=A[i,l]/A[i,i]:
   b[i,1]=b[i,1]/A[i,i]
  od:
  for j from i+1 to 4
   for k from i to 4 do
    A[j,k]=A[j,k]-A[j,i]*A[i,k]
   od:
   b[j,1]=b[j,1]-A[j,i]*b[i,1]
  od:
 fi:
od:

I definited matrix A and b, but this for loop doesn't work.

Thank you for your help.