Problem with solve and icdf
显示 更早的评论
Hi, I need to solve equations of the type b = @(x,s) solve(bb==x-s*icdf('Normal',bb,0,1),bb)
and after the function call
>> b(0.2,0.4)
I get this error. Can anyone help me?
Best,
Christian
Error using symengine Unable to prove 'bb < 0 | 1 < bb' literally. Use 'isAlways' to test the statement mathematically.
Error in sym/subsindex (line 821) X = find(mupadmex('symobj::logical',A.s,9)) - 1;
Error in sym/privsubsasgn (line 1096) L_tilde2 = builtin('subsasgn',L_tilde,struct('type','()','subs',{varargin}),R_tilde);
Error in sym/subsasgn (line 933) C = privsubsasgn(L,R,inds{:});
Error in norminv (line 57) p(p < 0 | 1 < p) = NaN;
Error in icdf (line 91) x = norminv(p,a,b);
Error in @(x,s)solve(bb==x-s*icdf('Normal',bb,0,1),bb)
采纳的回答
Star Strider
2018-9-20
It is probably best to avoid the Symbolic Math Toolbox for such problems.
Try this:
b = @(x,s,bb) x-s*icdf('Normal',bb,0,1)-bb;
B = fsolve(@(bb)b(x,s,bb), 0.01)
You may need a different initial parameter estimate (I used 0.01 here), depending on what ‘x’ and ‘s’ are. This uses the Optimization Toolbox fsolve (link) function. It is more robust than fzero.
更多回答（0 个）
类别
在 帮助中心 和 File Exchange 中查找有关 Mathematics and Optimization 的更多信息
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!
Translated by 
