Matlab如何求和函数

Question

i have to solve the following formulation in matlab:

i am looking for the beta value, given is a vector full of wavelet coefficients x =(x_1,..,x_L)! How to solve this function in matlab? Can i use fzero?

edit: at the moment i tried this:

syms beta
x = [-1; 2; 3; 4; 5]
exp1 = sum((abs(x).^beta).* log(x)) /sum(abs(x).^beta)
exp2 = log(beta/size(x)*sum(abs(x).^beta))/beta
exp3 = (exp(-t)*t^((1/beta)-1))/int(exp(-t)*t^((1/beta)-1),0,inf)
fzero(exp1-exp2-exp3-1,1)

but still errors..

Answer 1

fzero takes a function handle, rather than a symbolic expression. Try something like this in a .m file

function a = myFun(beta)
exp1 = sum((abs(x).^beta).* log(x)) /sum(abs(x).^beta)
exp2 = log(beta/size(x)*sum(abs(x).^beta))/beta
exp3 = (exp(-t)*t^((1/beta)-1))/int(exp(-t)*t^((1/beta)-1),0,inf)
a = exp1-exp2-exp3-1

And then,

fzero(@myFun,1)

I don't know whether this will work. but it is something to try out.