Christian Wolinski

MaplePrimes Activity

These are answers submitted by Christian Wolinski

gives this:


R := z = RootOf(-8649 + 270100*_Z + 9000*_Z^2 + 100*_Z^3, .3198736765e-1) .. .1;
A := [[3/2 + 1/10*(-8649+270100*z + 9000*z^2 + 100*z^3)^(1/2), z, 'R'], [3/2 - 1/10*(-8649 + 270100*z + 9000*z^2 + 100*z^3)^(1/2), z, 'R']];

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If you dont want something expanded, then name it:


CG:=proc(E) map(q -> collect(q, G, proc(E) if type(E, `*`) then map(collect, E, [F], factor) else collect(E, [F], factor) end if end@factor), E); end:

eqn := 5*(x*y)^2 + x/G = 2*F^3 + x^2, F = 3*x^3 + y^2, G^2 = y, G = sqrt(y);
#implicitdiff({eqn[1..-2]}, {y, F, G}(x), {y}, x):
implicitdiff({eqn[1..-2]}, {x, F, G}(y), {x}, y):
simplify(%, [eqn[-2]]);

applyop(CG, [1,2], convert(%, parfrac, G));
subs([eqn[2..-1]], %);  


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Maybe this is what you need:


GI := Gaussian(Z):
   local i, s, t, g;
   g := op('procname');
   i := g[Input](a), g[Input](b);
   i, PrincipalIdeal(g, i, 's, t'), s, t;
end proc;
F[GI](-87+47*I, -90+43*I); 


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What you are trying to do is specifically intended for the command simplify:


simplify(expr, [expression = V1]); 


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Two ways:


GST := AE + AI - ANB - AR - CP;

GSTf := evalindets(GST, name, unapply('unapply(a[i], i), a'));
GSTf ~ ([$1..3]);

GSTg := evalindets(GST, name, unapply('G[a], a'));
G := () -> op(procname)['args'];
GSTg ~ ([$1..3]); ;

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Replace the capital I in your formulas with lower case i and the problem will disappear. Capital I means (-1)^(1/2) which in algebraic formulas will be transformed by simplifications.


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This is a basic rule of valuations:


humb if you like.



A := Y = (-2*k^3+6*k^2+sqrt(k^8-12*k^7+64*k^6-198*k^5+448*k^4-636*k^3+369*k^2)-7*k-15)/((k^3-3*k^2+5*k-15)*(1+k));
collect((evala@Norm)((lhs-rhs)(A)), Y, proc(E) convert(E, parfrac, k, {I, sqrt(5)}); map(radnormal, %); end);
collect((evala@Norm)((lhs-rhs)(A)), Y, proc(E) convert(E, parfrac, k); map(normal, %); end); 

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Try these two. If you need the derivation I can post it too.




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How long does this example take on your computer?


T := w^3 + w*z + x^2 + 1, w*z + x*y + x*z + 1, w*x + w*z + y*z + z;
P := Expand(`*`(T)) mod 2;
Factor(P) mod 2;

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This code will suffice:


map(factor @ simplify, evecA1[2], [rho*c^2/(gamma-1)*(1/rho)+(1/2)*u^2 = H], [c, u, H]);

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Assuming your expression is contained in f, use the following code:


T[0]  := f:
T[10] := sqrt(omega) * 12^(1/4);
T[20] := evalindets(T[0], specfunc(anything, exp), exp @ proc(P) global T; radnormal(op(1, P) / T[10]) * T[10] end):
T[30] := [sqrt(omega) = Omega / (12^(1/4)), (omega) = (Omega / (12^(1/4)))^2];
T[40] := factor(expand(subs(T[30], T[20])));
T[50] := [exp(Omega) = beta[1], exp(I * Omega) = beta[2]];
T[60] := factor(radnormal(subs(T[50], T[40]))):
op(map(rhs = lhs, T[50])), Omega = solve(T[30][1], Omega), T[60];


omega = RootOf(cos(2*12^(1/4)*sqrt(_Z))*(exp(2*12^(1/4)*sqrt(_Z)))^2+cos(2*12^(1/4)*sqrt(_Z))-2*exp(2*12^(1/4)*sqrt(_Z)), 4.450852611);
omega = (1/24)*RootOf(cos(_Z)*exp(2*_Z)+cos(_Z)-2*exp(_Z),7.853204624)^2*sqrt(3);

Try this instead:


_interface(showassumed = 0):
assume(x > 0, t > 0, k > 0):
pde := diff(u(x, t), t) = k * diff(u(x, t), x$2):
ic := u(x, 0) = 0:
bc := u(0, t) = t:
sol:= pdsolve({pde, ic, bc}, u(x, t)):

Your problem arises from assume/additionally as it generates a chain of assignments every time you make an assumption on a variable. The is/assume facility responds to every variable in the chain the same way, but we can expect pdsolve does not, hence your error. Simply put the assumption (assignment) at the beginning of everything. Alleviating this difficulty was the one of the reasons why "assuming" was created.

Evalb is too literal and not intended for the test case you included. For floats you'd always use fnormal.

If you know the solutions are reals then:


`@`(sort, combine, expand, evalc, map)(Re, [solve](5*x^3 - 5*x + 1, x));

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