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Christian Wolinski

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20 years, 314 days
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These are replies submitted by Christian Wolinski

Drink & be merry....

Christian Wolinski 1495
October 26 2018
0 0

@vv If you do not know what is expected then you can safely assume this cup is not what you would drink. There are other threads where you would contribute instead.

Codes are meant to be legible....

Christian Wolinski 1495
October 26 2018
0 0

@Carl Love Codes are meant to be legible, understandable, presentable, explainable. If this is intended by the designers, then how is the following interpreted? Please read the code and compare it to the the results. Interpret the code before it executes. I woke myself from my Maple V slumber into this Maple 2017 horror show:

 

restart;
g:=proc() local j; j:=op(procname); j:=g[j+1]; applyop(x->eval(x,2),0,'j(args)'); end;

f:=[g[0]];
f(0), f(0)(0), f(0)(0)(0);
f:=[[g[0]]];
f(0), f(0)(0), f(0)(0)(0);
f:=[['g[0]']];
f(0), f(0)(0), f(0)(0)(0);
f:=[[''g[0]'']];
f(0), f(0)(0), f(0)(0)(0);
f:=[g[0](0)];
f(0), f(0)(0), f(0)(0)(0);
f:=[[g[0](0)]];
f(0), f(0)(0), f(0)(0)(0);
f:=[['g[0](0)']];
f(0), f(0)(0), f(0)(0)(0);
f:=[[''g[0](0)'']];
f(0), f(0)(0), f(0)(0)(0);

 

Death....

Christian Wolinski 1495
October 26 2018
0 0

@Carl Love Is it safe to say symbolic computation is dead with Maple?

Something amiss....

Christian Wolinski 1495
October 23 2018
0 0

What is RonanRoutines?

A little complicated....

Christian Wolinski 1495
October 17 2018
0 0

@Ronan How about this:

 

A := (lhs-rhs)(eq3);
L := ([op]@indets)(%, radext);
R := convert(L, RootOf):
(evala@Norm)(subs(L =~ R, A), {}, indets(R, algnumext));
# or in a case when needed:
subs(R =~ L, (evala@Norm)(subs(L =~ R, A), {}, indets(R, algnumext)));


Thumb if you like.

Clarification....

Christian Wolinski 1495
October 13 2018
0 0

Can you specify which science, subject produced this matrix?

Derivation....

Christian Wolinski 1495
October 12 2018
0 0

@Ahmed111 

You can use this code.

 
 

restart;
cH := proc (x) options operator, arrow; conjugate(x) = abs(x)^2/x end proc;
rH := proc (x) options operator, arrow; x = 2*Re(x)-conjugate(x) end proc;
fe := proc(f) frontend(f, [args[2..-1]],[{Non}({op(procname)}), {}]) end;

A := Matrix([[phi, conjugate(psi), chi, conjugate(rho)], [psi, -conjugate(phi), rho, -conjugate(chi)], [lambda1*phi, conjugate(lambda1)*conjugate(psi), lambda2*chi, conjugate(lambda2)*conjugate(rho)], [lambda1*psi, -conjugate(lambda1)*conjugate(phi), lambda2*rho, -conjugate(lambda2)*conjugate(chi)]]);
dA := LinearAlgebra:-Determinant(A);

map(cH, [phi, chi, rho, psi]);
T[1] := map(numer@(lhs-rhs), %), plex((op@map)(lhs, %), (op@map)(op@lhs, %));

map(expand@cH, [lambda1-lambda2, conjugate(lambda1)-(lambda2)]);
T[2] := map(expand@numer@(lhs-rhs), %), plex(op(indets(% ,specfunc(conjugate))), op(indets(% ,specfunc(abs))));

expand([rH(conjugate(phi)*conjugate(rho)*chi*psi)]);
T[3]:=map(expand@numer@(lhs-rhs), %), plex(op(indets(% ,specfunc(conjugate))), op(indets(% ,specfunc(Re))));

fe[specfunc(anything, {conjugate, abs})](expand@simplify, dA, T[1]);
collect(%, abs, distributed, factor);
fe[specfunc(anything, {conjugate, abs})](expand@simplify, %, T[2]);
fe[specfunc(anything, {conjugate, abs, Re})](expand@simplify, %, T[3]);
dA2:=fe[function](collect, %, indets(%, anyfunc(dependent({lambda1, lambda2}))), distributed, factor);

collect(dA2, Re);
coeff(%, Re(conjugate(phi)*conjugate(rho)*chi*psi), 1)+8*Im(lambda1)*Im(lambda2):
(% = expand(convert(%, conjugate)))*Re(conjugate(phi)*conjugate(rho)*chi*psi);
dA3 := collect(dA2-lhs(%), indets(%, anyfunc(dependent({lambda1, lambda2}))));

dA;dA2;dA3;


Thumb if you like.

Fail....

Christian Wolinski 1495
October 11 2018
0 0

Following is an example which I consider a failure in symbolic computation. Am I overreacting? It simply demonstrates the fact that unless the parameter is inert (not active like g()) it cannot be safely used in an identity because it may be distributed. 

 

restart;
g := proc(n) global i; local j;
   if not type([i], [integer]) then i := 0; fi;
   j := i;
   i := i + 1;
   x[j];
end;

f(g());
A := f = a + b + c;
assign(A);
W[1] := 'f'(g());
W[2] := '%' = %;
W[3] := (''f'' = 'f')(g());  


.

Changes....

Christian Wolinski 1495
October 11 2018
0 0

@acer The composition rule demonstrated by Op & Op2 was a clad rule of Maple programming. It holds true in 5.4, it does not hold true in Maple 2017. I did not notice, or maybe I forgot. I am interested to know when this change was implemented. Where is this announced, where is the narrative for this change?

Versioning....

Christian Wolinski 1495
October 10 2018
0 0

So which versions fail this and how is this explained. I feel like this is an old issue.

Edit: the results wont be equal, but they should be similar.

 

Op := proc(R,F)
 a := R, R;
 F(a());
end:

Op2 := proc(R,F)
 a := R, R;
 a := a();
 F(a);
end;

([Op] = [Op2])(rand(1 .. 9), [f, f]);


 

Basic types....

Christian Wolinski 1495
September 08 2018
0 0

@Carl Love I am most interested in satisfying test1 using builtin types. Since satisfies was introduced this idea is confused, satisfies is just a torture test. I thought atomic might be the type I was looking for, but it is not.

Not really what I was thinking about....

Christian Wolinski 1495
September 07 2018
0 0

@Carl Love I would consider that a run around my question, since that type is just an arbitrary procedure call. It does not identify a Maple type.

Welcome....

Christian Wolinski 1495
August 19 2018
0 0

@maple2015 Thumb if you like. It helps :D

First dimension....

Christian Wolinski 1495
June 26 2018
0 0

@Carl Love Replace the 600 with something of order of 1500. What is the ceiling? Can we count real roots of a polynomial this size?

Counting....

Christian Wolinski 1495
June 26 2018
0 0

@Carl Love What is the best way to count real roots of a polynomial this size. (Unfortunately this polynomial factors)

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