LeeHoYeung

Mr. Ho Yeung Lee

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12 years, 234 days

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Seldom to ask question after retired math hobby Welcome August, February, July, May born girl And waited for her email to mavio@protonmail.com

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These are questions asked by LeeHoYeung

how to count how many terms or items are equal when compare two lists of polynomial terms when length of two list may not be equal

let aa = map (+1.2) [1,2]
let bb = map (+1.4) [2,3]
foldr (aa . bb) [3.0,4.0]

n := 5:
z1 := exp(2*3.14*I*k1/n)*cosh(z)^(2/n);
z2 := exp(2*3.14*I*k2/n)*sinh(z)^(2/n);
xx := Re(z1);
yy := Re(z2);
uu := cos(alpha)*Im(z1) + sin(alpha)*Im(z2);

use above example of calabi yau equation, do not know which variables z, k1, k2 are u and v, then i assume k1 and k2 are u and v respectively,

 

E := diff(xx,k1).diff(xx,k1);
F := diff(xx,k1).diff(xx,k2);
G := diff(xx,k2).diff(xx,k2);

then calculate metric
diff(E, k2);
F
diff(G, k1);

which function can input these metric diff(E,k2), F, diff(G,k1) to prove calabi yau equation's metric's ricci is flat

Round := proc(x,n::integer:=1)
parse(sprintf(cat("%.",n,"f"),x));
end proc:

roundcoeffs1:=proc(p,x,n:=1) local t,c;
c:=map(Round, [coeffs(p,x,t)],n);
add(i, i = zip(`*`, c, [t]));
end:

ggg:=.9940413618*y^3-1.785839107*c*A*y^3-2.357517322*c*A*y^2+.375393240*c*y*B-.3575173222*c*A*y-.2082022533*c*B-0.1787591445e-1*y^2-0.1787591445e-1*y-0.5958638151e-2+.2141608926*c*A+.7917977467*c*B*y^3+2.375393240*c*B*y^2;

roundcoeffs1(ggg, [y^3, c*A*y^3, c*A*y^2, c*y*B, c*A*y, c*B, y^2, y, c*A, c*B*y^3, c*B*y^2], 4);


Error, (in sprintf) number expected for floating point format

with(Optimization):

theta := Complex(1,1);
Minimize(theta^3-3*(A*theta^2+B), {0 <= theta^3-3*(A*theta^2+B)}, assume = nonnegative)

Error, (in Optimization:-NLPSolve) complex value encountered

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