Code for equation with ln
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How can i Code it?
u=0.23 y=0.3 v=0.00001
u/u’=5*log(u’*y/v)-3.05
u’=?
I need to find the value of u’.
回答（1 个）
Star Strider
2018-10-21
Try this:
u=0.23;
y=0.3;
v=0.00001;
fcn = @(ustar,u,y,nu) 5*log(ustar.*y/nu)- 3.05 - u/ustar;
ustar = fsolve(@(ustar)fcn(ustar,u,y,v), 1)
ustar =
0.00918407730971717
2 个评论
Sayeed
2018-10-21
Star Strider
2018-10-21
I already posted all the code that is needed to solve this problem.
You need to have the Optimization Toolbox installed to use fsolve.
You will have fminsearch regardless, so try using fminsearch on the norm of ‘fcn’:
ustar = fminsearch(@(ustar)norm(fcn(ustar,u,y,v)), 1)
ustar =
0.00918426513671787
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2018-10-21
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