I had a warning solutions may be lost for the following:

with(plots);
with(plottools);
with(DEtools);
solve({0.5*`sinφ` + 0.5*`sin2φ` + 0.5*sin(-phi) + 0.5*sin2(-phi) - 0.5*sin(phi + psi) + 0.5*sin2(phi + psi) - 0.5*`sinψ` + 0.5*`sin2ψ`, ((-0.5*`sinφ` - 0.5*`sin2φ` + 0.5*sin(-phi - psi) + 0.5*sin2(-phi - psi)) - 0.5*`sinφ`) + (0.5*`sin2φ`)*0.5*sin(-psi) + 0.5*sin2(-psi) = 0}, {phi, psi});
Warning, solutions may have been lost

Any suggestions

Does maple have an code for computing point addition on elliptic curves? 

BIOMAT_project.mw

I have this Math Biology project I am working on. I have a set of differential equations that I would like to plot the solutions of, but I am not familiar enough with Maple to do so. The attached is all of the work that I have done so far. What is the best way to plot these solutions? 

Hi

I'm trying to rearrange a transfer function to get my s^2 term with other specific terms . Below is the denominator of the transfer function. I know that my goal is to get (Izz*u)/m for the s^2 term, so I divide by Df*Dr*(a+b)*u*m, as shown below.

However, if we look at the s^2 terms for now, the equation should be further simplified leaving me with simply (Izz*u)/m, but Maple doesn't want to do this for some reason, and if I use simplify on the above expression it tries to expand everything again, and forgetting about my collect(fun, s).

Is there any way to get around this?

Many thanks

Dear all

I have a function g that I compute its limit at x0 

but when I compute series(g(x),x=x0) then I compute the limit of the series I get different limit

series_limit.mw

Many thanks for your help

Hi

I have a piecewise equation,and two Sum (one of them is infinity and the other has upperband k). I need a numerical value for F2. 

H := r->; piecewise(r < 1, 1);

XF := x-> 2;

f1 := k-> sum(XF(j)*(1-H(j)), j = 0 .. k);

F2:=sum(f1(i), i = 0 .. infinity);

Hi, 

This is a question more or less related to this one Is it possible to define variables with unusual na... but I think it's better to open a new thread. If some think otherwise, please feel free to displace it to the link above.

I want to relabel the vertices of a graph by using special characters.
It happens that this works perfectly if I do not impose the style of the drawing but that it doesn't if I set, for instance, spring=style.
In the attached file you will see that the subsitution of the old vertex names by the new ones doesn't work if apply it directly on the many operators of the PLOT command contains.

Is this behaviour fixed in more recent versions of Maple or it's still present?


Strange-Behaviour-with-SpringStyle.mw

Why does Maple not have texture fill for plotting. Even the old Pascal had it.

Maple Help points out

All Programs>Maple 2017>Classic Worksheet Maple 2017

link that I do not have. Is there a reason for this and how do I fix this?

I don't understand whats wrong with my code
r(x):=proc(x) 
    local y
    if (x=1)
    then    
    y=1;
    else 
        y=0;
    end if; 
    return y
    end proc    

Error, reserved word `if` unexpected

I'm also having trouble getting this code to work:

h(x):=proc(x) 
    if (x= infinity)
    then    
    return 1 ;
    else 
        return 0;
        end if; 
    end proc 
theres no error but h(0) just returns h(0) not either value as I would like

Dear All,

How do I use the piecewise function z[k]:=piecewise(k<>0,0,k=0,1) in the loop 

for k from 0 to 10 do

(sum((m^2-1)/z(z[k]+1),m,0..k))

end:

i want the value of z[k] to be automatically used in the loop for the corresponding value of k

Graph the real roots of the equation x3 + (a − 3)3x2 − a2x + a3=0 for a ∈ [0, 1].

Sol:=[solve(x^3+(a-3)^3*x^2-a^2*x+a^3=0,x)];

for i from 1 to 3 do

R||i:=unapply(Sol[i],a):

print(plot(R||i(a),a=0..1,numpoints=500)); end od:

Is there a simplier way to solve this. If not why did they choose this path?

@Carl Love 

Can you help me to make a 1D plotting by using this data? 

Dear all

Can we use maple to compute integral using the residual theorem

Compute_integral.mw

We can consider the contour a circle that contains one pole (Ipi/2)

Many thanks

Hi! I have been trying to calculate the value of theClenshaw derivative. I can get the regular clenshaw to work but not the derivative. I'm going off of the thread (https://scicomp.stackexchange.com/questions/27865/clenshaw-type-recurrence-for-derivative-of-chebyshev-series). (P.s notice I have halfed the A[z+1] term. I have tried both ways but the overall result is wrong so I am guessing something more important is wrong).

This is my code so far

Clenshaw_Dx_1D:=proc(z,C,Nm,s)
local i,k,A,B: global Clen1D_Dx: 

A := Vector(z..Nm+1+z);
B := Vector(z..Nm+1+z);

for k from Nm-1+z by -1 to 1+z do
A[k] := C[k] + 2*s*A[k+1] - A[k+2]:
od:

for k from Nm-1+z by -1 to 1+z do
B[k] := 2*A[k+1] + 2*s*B[k+1] - B[k+2]:
od:
Clen1D_Dx :=  A[z+1]/2 + s*B[1+z] - B[2+z]:

end:

Where z could be 0 or 1 depending on what index your C array starts at. C is the array of chebyshev coefficients of a Chebyshev series appromating u(x) for example. The Chebycoeff1D procedure calculates the Chebyshev coefficients  and the code below calls the procedure for a specific function. Try it with some values of xM, for example 4-10.
 

Chebycoeff1D:=proc(express,Nn,C2,A,B)
local Cfac,fac1x,fac2x,k,K;

fac1x:=Pi/Nn;
  for k from 1 to Nn do 
  Cfac(k):=eval(subs(x=evalf(cos(fac1x*(k-0.5)))*A+B,evalf(express))); 
  od; unassign('k'):                    
  for K from 1 to Nn do
    fac2x:=Pi*(K-1)/Nn;
    C2[K-1]:=(2/Nn)*add(Cfac(k)*evalf(cos(fac2x*(k-0.5))),k=1..Nn);
  od:
end:

nn := 1.0:
Lc := 0.0: Rc := 1.0:
func:=nn*sin(2*Pi*x)+0.5*nn*sin(Pi*x):
Chebycoeff1D(func,xM+1,C,0.5*(Rc-Lc),0.5*(Rc+Lc)):

Once you have the C array call Clenshaw_Dx_1D. For example
 

Clenshaw_Dx_1D(0,C,xM+1,0.0);  # Evalutes f'(x) in the middle of the domain.

Check with

subs(x=0.5, diff(func,x));

The overall "pattern/shape" of the derivative values is correct, just not the amplitude/values. Any help here? Where is the Clenshaw derivative procedure going wrong.