What is wrong in script?
显示 更早的评论
for m1 =0:M
T2=0;
for m2=0:M
T3=0;
for s1=0:m1/2
T4=0
for j1=0:m1-2*s1
T5=0
for s2=0:(M-m1)/2
T6=0;
for j2=0:(M-m1-2*s2)
T6=T6+(1/(po^2))^j2;
end
T5=T5+T6*((2*1i)/(delta^(0.5)))^(M-m1-2*s2);
end
T4=T4+T5*(1/(po^2))^j1;
end
T3=T3+T4*((2*1i)/(delta^(0.5)))^(m1-2*s1);
end
T2=T2+T3*(factorial(M)/(factorial(m2)*factorial(M-m2)));
end
T1=T1+T2*(factorial(M)/(factorial(m1)*factorial(M-m1)));
end
10 个评论
Just out of interest: Where do all these horrible sums stem from that you posted during the last days and weeks ?
What is meant if the sum goes to m1/2 or (M-m1)/2 ? Is it the usual treatment that summing up to 5/2, e.g., means summing for 0,1 and 2 ?
Further, you didn't give values for variables and loop limits. So nobody can tell what you mean by "What is wrong in Script ?" because nobody can test it.
Athira T Das
2022-7-23
Torsten
2022-7-23
And what about the loop limits ?
Jan
2022-7-24
@Athira T Das: Please share the important information with the readers: Why do you assume, that the script is wrong?
Is this the code you try to run ?
M = 3;
w = 0.2;
z = 0:10000;
k = 5.9275e+06;
Po = (k^2*z).^(-(3/5));
Delta = 1i*k./(2*z) + 1/w^2 + 1./Po.^2;
po = Po(1);
delta = Delta(1);
T1 = 0;
for m1 =0:M
T2=0;
for m2=0:M
T3=0;
for s1=0:m1/2
T4=0;
for j1=0:m1-2*s1
T5=0;
for s2=0:(M-m1)/2
T6=0;
for j2=0:(M-m1-2*s2)
T6=T6+(1/(po^2))^j2;
end
T5=T5+T6*((2*1i)/(delta^(0.5)))^(M-m1-2*s2);
end
T4=T4+T5*(1/(po^2))^j1;
end
T3=T3+T4*((2*1i)/(delta^(0.5)))^(m1-2*s1);
end
T2=T2+T3*(factorial(M)/(factorial(m2)*factorial(M-m2)));
end
T1=T1+T2*(factorial(M)/(factorial(m1)*factorial(M-m1)));
end
T1
Athira T Das
2022-7-24
编辑：Athira T Das
2022-7-24
What about the value for k ?
sqrt(0.545) or 5.9275e6 ?
What about the upper looplimit ? Like this: loop over integers up until 2 ?
k = 0;
for j = 0:5/2
k = k + 1;
end
k
Athira T Das
2022-7-24
编辑：Athira T Das
2022-7-24
Torsten
2022-7-24
k = 5.9275e+06
And why do you write
rho = (0.545*z)^(-3/5)
instead of
rho = (5.9275e+06^2*z)^(-3/5)
in your formula ?
Athira T Das
2022-7-24
回答（1 个）
I would have progrmmed it this way, but the result seems to be the same.
My guess is that there is a mathematical trick to extremely simplify the expression (something like sum_{i=0}^(i=n} nchoosek(n,i) * p^i * (1-p)^(n-i) = 1), but I don't see it at the moment.
M = 3;
w = 0.2;
z = 0:10000;
k = 5.9275e+06;
Po = (k^2*z).^(-(3/5));
Delta = 1i*k./(2*z) + 1/w^2 + 1./Po.^2;
po = Po(1);
delta = Delta(1);
X = 0;
for m1 = 0:M
faktor = nchoosek(M,m1);
sum1 = 0.0;
for s1 = 0:m1/2
faktor1 = (2*1i/sqrt(delta)).^(m1-2*s1);
sum_inner = 0.0;
for j1 = 0:m1-2*s1
sum_inner = sum_inner + (1/po^2)^(j1);
end
sum1 = sum1 + faktor1*sum_inner;
end
sum2 = 0.0;
for s2 = 0:(M-m1)/2
faktor2 = (2*1i/sqrt(delta)).^(M-m1-2*s2);
sum_inner = 0.0;
for j2 = 0:M-m1-2*s2
sum_inner = sum_inner + (1/po^2)^(j2);
end
sum2 = sum2 + faktor2*sum_inner;
end
X = X + faktor*sum1*sum2;
end
X = X*2^M
4 个评论
Athira T Das
2022-7-24
编辑：Athira T Das
2022-7-24
Torsten
2022-7-24
Since all the expressions don't depend on m2, you can take the sum out and it gives
sum_{k=0}^{k=M} nchoosek(M,k) = 2^M
Athira T Das
2022-7-25
I think something like this:
M = 6;
w = 0.2;
z = 0:10000;
k = 5.9275e+06;
Po = (k^2*z).^(-(3/5));
Delta = 1i*k./(2*z) + 1/w^2 + 1./Po.^2;
po = Po(1);
delta = Delta(1);
X = 0;
for m1 = 0:M
faktor_m1 = nchoosek(M,m1);
sum_m2 = 0.0;
for m2 = 0:M
faktor_m2 = nchoosek(M,m2);
sum1 = 0.0;
for s1 = 0:m1/2
faktor1 = (2*1i/sqrt(delta)).^(m1-2*s1);
sum_inner = 0.0;
for j1 = 0:m1-2*s1
sum_inner = sum_inner + (1/po^2)^(j1);
end
sum1 = sum1 + faktor1*sum_inner;
end
sum2 = 0.0;
for s2 = 0:(M-m1)/2
faktor2 = (2*1i/sqrt(delta)).^(M-m1-2*s2);
sum_inner = 0.0;
for j2 = 0:M-m1-2*s2
sum_inner = sum_inner + (1/po^2)^(j2);
end
sum2 = sum2 + faktor2*sum_inner;
end
sum_m2 = sum_m2 + faktor_m2*sum1*sum2;
end
X = X + faktor_m1*sum_m2;
end
X
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2022-7-23
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