I wrote a code for the following sequence. But I have a problem. What are the good methods for defining recursive sequence?

THE CODE

restart;
#FIRST STEP: Lets find the recursive formula for 
d:=proc(m)
option remember;
d(1):=1;
if m>1 then return -sum(xi(i)*d(i-k+1),i=2..m) else 1 fi;
end proc:
#lets check
for i from 1 to 4 do
d(i);
end do; 

Secondly, I want to create a matrix as follows. I wrote the code. I think it is right.

restart:
m:=4:
DD:=Matrix(m,m):
#SECOND STEP: Lets find the matrix 
for i from 1 to m do 
p:=0:
for j from 1 to m do 
 
if i<=j then p:=p+1:
DD[i,j]:=d(p);
 fi: 
end do;
p:=1: 
end do:
DD;

I am working with lines in 2- and 3-space, defined parametrically. In 2-space, how would I go about using Maple to determine if the lines are identical or parallel. For example, if L1:=<2-4*t,5+6*t>, L2:=<-6-12t,17+18t>, L3:=<20t,-30t>, I would like a procedure that would be able to determine that L1 and L2 are identical lines, and that L1 and L3 are parallel lines. Similarly, it would be able to determine if lines in 3-space, are identical, parallel, or skew. 

I was looking into the geometry package, but I don't think it allows me to do this.

Thanks!

 Mathematical model for the temperature profiles of steel pipes quenched by water cooling rings

Hi

 Can anyone solve the given equations along with the boundary conditions analytically with Maple and draw the graphs ???????????

Hi everyone,

I'm trying to define indexed functions inside a for loop. However, after the loop is completed, the indexes of the functions are replaced by the índex of the control variable of the loop plus one. For example, I can make successfully the code:

for i from 1 to n do a[i] := b[i]; od;

However, if I try to define the functions a[i](u), through the code 

for i from 1 to n do a[i] := u-> b[i](u); od;

 I get wrong assignments. For example, Maple returns to me, for any i<=n, a[i](u) = b[n+1](u). 

I'm using Maple 2019 on Windows. Is this a bug? There is a right way to do these function assignments inside a loop?

Best regards for all,

R. S. Vieira.

In a new worksheet

gcd(a,b);
                               1

Why is maple computing this? It does it for a lot of functions and I never know if it is giving the correct results. a and be are not defined. I'd expect it to just return gcd(a,b).

I put it in formulas but I never know if it is simplifying before computing. I have no idea why. Maple never did this stuff until I upgraded.

maple save variables is greyed out  would anyone happen to know why this could be the case?

                       tmmp := [1, 10 q]
                            PS1 := 1
                          PS2 := 10 q
                           [1, 10 q]
                        tnmp := [8, 5 q]
                            QS1 := 8
                           QS2 := 5 q

gP, gQ, S1, S2, P1, P2, Q1, Q2

(q*x + 9*q + y)^33*(4*q*x + 6*q + y)^16/((x + 3)^48*(x + 10)), (q*x + 9*q + y)^33*(4*q*x + 6*q + y)^16/((x + 3)^48*(x + 10)), 8, 6*q, 1, q, 1, -10*q    

Normal(Eval(gP, {x = QS1, y = QS2})*Eval(gQ, {x = S1, y = -S2})*1/(Eval(gP, {x = PS1, y = PS2})*Eval(gQ, {x = S1, y = -S2}))) mod p;
Error, (in mod/Normal) invalid arguments or not implemented
 

Hello people in mapleprimes,

I could modify an expression e_n_1b to simpler e_n_1e as is in attached file.
Is there any other way to change e_n_1b into e_n_1e?

Dec_22.mw

Thank you in advance.

taro

P1 := 1;
Q1 := 1;
P2 := q;
Q2 := -10*q;
p - 11;
                            P1 := 1
                            Q1 := 1
                            P2 := q
                          Q2 := -10 q
                               0
NULL;
if Q2 = P2 mod p then
    return 42;
else
    return 0;
end if;
(P2 - Q2) mod p;
                               0

I don't know why but   (p=11)   here the code below does not return 42  and 

evalb(Q2 = P2 mod p);      returns
                             false   

I am trying to find 6 unknowns A, B, C, L, E, and F and have managed to write down a system of 6 equations involving these unknowns.  However, the equations are long and which I try to put the system together and solve with solve(sys, {A, B, C, E, F, L}) it says `[Length of output exceeds limit of 1000000]`.  Although the equations are long, I feel like something must be going wrong as the output cannot be that long.  The equations are:

C = (((h/(4*Pi*K)*H*e^(-k*h)*I/k - k*h^2/2 + H*A*e^(-k*h)*I/(K*k^2) - B*h - sqrt(Pi/2)*h/(2*Pi)*H*e^(-k*h)*I + sqrt(Pi/2)*K*k*h - sqrt(Pi/2)*H*A*e^(-k*h)*I/k + sqrt(Pi/2)*B*K - sqrt(Pi/2)*K*H*k*h^2*I/2) + sqrt(Pi/2)*H*A*e^(-k*h)*I/k) - sqrt(Pi/2)*H*F*h*K*I - sqrt(Pi/2)*H*A*e^(-k*h)*I/k + sqrt(Pi/2)*K*H*k*h^2/2*I) - sqrt(Pi/2)*H*F*h*K*I,

E = (((h/(4*Pi*K)*J*e^(-k*h)*I/k - k*h^2/2 + J*A*e^(-k*h)*I/(K*k^2) - L*h - sqrt(Pi/2)*h/(2*Pi)*J*e^(-k*h)*I + sqrt(Pi/2)*K*k*h - sqrt(Pi/2)*J*A*e^(-k*h)*I/k + sqrt(Pi/2)*L*K - sqrt(Pi/2)*K*J*k*h^2*I/2) + sqrt(Pi/2)*J*A*e^(-k*h)*I/k) - sqrt(Pi/2)*J*F*h*K*I - sqrt(Pi/2)*J*A*e^(-k*h)*I/k + sqrt(Pi/2)*K*J*k*h^2/2*I) - sqrt(Pi/2)*J*F*h*K*I

0 = -H*(k*z^2/2 - H*A*e^(-k*z)*I/(K*k^2) + B*z + C)*I - J*(k*z^2/2 - J*A*e^(-k*z)*I/(K*k^2) + L*z + E)*I + k*z + A*e^(-k*z)/K + F

0 = ((-H*A*e^(-k*z)*I - H*I*(-2*K*(-H*k*z^2*I/2 - H^2*A*e^(-k*z)/(K*k^2) - H*B*z*I - H*C*I)) - J*I*(-2*K*1/2*(((-J*k*z^2*I/2 - J*H*A*e^(-k*z)/(K*k^2) - J*B*z*I - J*C*I - H*k*z^2*I/2) - J*H*A*e^(-k*z)/(K*k^2)) - H*L*z*I - i*H*E)) - K*k) + H*A*e^(-k*z)*I) + K*H*z*k*I + H*A*e^(-k*z)*I + K*H*F*I

0 = ((-J*A*e^(-k*z)*I - H*(((K*J*k*z^2*I/2 + J*H*A*e^(-k*z)/k^2 + K*J*B*z*I + k*h*K*z^2*I/2) + J*H*A*e^(-k*z)/k^2) + K*H*L*z*I + K*H*E*I)*I - J*I*(-2*K*(-J*k*z^2*I/2 - J^2*A*e^(-k*z)/(K*k^2) - J*L*z*I - J*E*I)) - K*k) + J*A*e^(-k*z)*I) + K*J*z*k*I + J*A*e^(-k*z)*I + K*J*F*I

0 = (-k*A*e^(-k*z) - H*I*(-2*K*1/2*(((k*z + H*A*e^(-k*z)*I/(K*k) + B - H*k*z^2*I/2) + H*A*e^(-k*z)*I/(K*k)) - H*F*z*I - H*G*I)) - J*I*(-2*K*1/2*(((k*z + J*A*e^(-k*z)*I/(K*k) + L - J*k*z^2*I/2) + J*A*e^(-k*z)*I/(K*k)) - J*F*z*I - J*G*I)) - 2*K*k) + 2*k*A*e^(-k*z)

where h takes a constant value, H and J are constants, k is the square root of H^2 + J^2, I is the imaginary unit, and z also takes some value as a parameter.

I'm new to maple and numerical analysis in general and I have a problem, I'm not sure how to assign variables into a function with the submethod rk4, the equation is very simple:

dy/dx=10(y-a)/b, where a and b serve as functions of x, and are given different values with the change of x.How do I assign these values?

Thanks.

Error, invalid subscript selector
WeilP:
   7       PS1 := temp[1];
============================================

WeilP:=proc(m, P1, P2, Q1, Q2, f, p) 
local S1, S2, gP, gQ, temp, PS1, PS2, QS1, QS2;
    if [P1,P2] = [Q1, Q2] mod p then
        return 1 ;
        else  
            # [S1, S2] := EAdd( f, x, P1, P2, Q1, Q2); 
            temp := EAdd( f, x, p, P1, P2, Q1, Q2);
            S1:= temp[1];
            S2:=temp[2];
        temp := EAdd( f, x, p, P1, P2, S1, -S2);   #represents P-S  
            PS1:= temp[1];
            PS2:=temp[2];
        temp := EAdd( f, x, p, Q1, Q2, S1, S2);    #Q+S
        QS1:=temp[1];
        QS2:=temp[2];
    #        gP:=Weil( m, P1,P2, f, p ); 
    #        gQ:=Weil( m, Q1,Q2, f, p );
    return 0
#    return Normal(  ( Eval(gP, { x=QS1, y=QS2 } ) * Eval(gQ, {x=S1, y= -S2} ) )  / ( Eval(gP, { x=PS1, y=PS2 } ) * Eval(gQ, {x=S1, y= -S2} ) )   )  mod p;    # ( f_P(Q+S) f_Q(-S)  ) / ( f_Q(P-S) f_P(S)  )
    end if ;

Here EAdd is elliptic curve addition   

I tried evaluating the code outside the code edit region and it seemed to work okay  temp ends up being the vector 

p.s. how do I get maple to save the values of a procedure rather than deleting them? 

how do I view variable values during debugging? 

How do I get the line number of where the error occurred? 
The errors messages in maple tell you nothing.

p.s. How do I get the debugger to keep the display of code after it hits an error? 
 Where does the copy results on exit copy to? 
How do I know where I am in the code? (e.g. the matlab debugger just goes into the code you wrote  but when do outfrom it's not clear where I am now  )
How do I view variable values whilst debugging? How do I quit the debugger and save variables?  Can I set a procedure to quit and return variables? 

can I set a break in a procedure to quit and keep variable values?

I have 4 ode equations. i just want to know can i use any option or simplification to have a analytical solution or NOT? Thanks in Advance

 

Download 1.1.mw

###(*         test code 
test:=proc(aa,bb)

P1:=1; 
P2:=2;  

    P1:=aa; 
    P2:=bb;
 
f:=x^3+x+2;
p:=13; 
k:=2;
tmp:=field(p,k);
q:=tmp[1];
Po:=tmp[2];
L1:=P1; 
L2:= P2;
m:=1; 
while (L1 <> infinity) and (m < 25 ) do
temp:= EAdd(f, x, p, P1,P2,L1,L2) ;
L1:=temp[1];
L2:=temp[2];
m:=m+1;
end;

return 0;
end proc ;
#    *)

stopat(test, 24);

Error, (in stopat) statement number out of range  

Line 24 is the line after m:=m+1 so why is it out of range???