i am trying to get the value for b.
where
t = [89;132;202;263;321;362;421;473;575;663]
n=10;
syms b
[b] = solve((1/b) + sum(log(t))/10 - 1.*sum(t.^b).*log(t)/(sum(t.^b))==0)
i tried this code to find 'b' but i am not getting the value of 'b'. How can i get the value for 'b'?

 Réponse acceptée

Ameer Hamza
Ameer Hamza le 23 Oct 2020
If you want to find value of 'b' for each value of 't' then try this
tv = [89;132;202;263;321;362;421;473;575;663];
syms b t
b_sol = solve((1/b) + sum(log(t))/10 - 1/(sum(t.^b)/10).*sum(t.^b).*log(t)==0, b);
b_vals = subs(b_sol, t, tv)

5 commentaires

MD. Rokibujjaman sovon
MD. Rokibujjaman sovon le 23 Oct 2020
Modifié(e) : MD. Rokibujjaman sovon le 23 Oct 2020
i am not looking for each t. 'b' will have a single value and it would be 2.0924
Ameer Hamza
Ameer Hamza le 23 Oct 2020
Can you show your equation in latex form?
MD. Rokibujjaman sovon
MD. Rokibujjaman sovon le 23 Oct 2020
i added the question.
You were also dividing the term in the denominator by 10. Try the following code
t = [89;132;202;263;321;362;421;473;575;663]
n=10;
syms b
b_sol = solve((1/b) + sum(log(t))/10 - 1/(sum(t.^b)).*sum((t.^b).*log(t))==0)
Result
b_sol =
2.0923855034345368572888674897445
MD Rokibujjaman Sabuj
MD Rokibujjaman Sabuj le 23 Oct 2020
Thanks.

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Plus de réponses (1)

Walter Roberson
Walter Roberson le 23 Oct 2020

0 votes

Your t is a vector.
[b] = solve((1/b) + sum(log(t))/10 - 1/(sum(t.^b)/10).*sum(t.^b).*log(t)==0)
You have log(t) there at the end, in a context that is not inside a sum() like the rest of the places you use t. Therefore you are generating a vector of equations, and you are asking solve() to find a single t that solves all of the equations simultaneously.
You need to re-check your last term. For example there is a numeric solution for
vpasolve((1/b) + sum(log(t))/10 - 1/(sum(t.^b)/10).*sum(t.^b.*log(t))==0, 0.02)

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