在Matlab中使用fzero时出错：类型为\'function_handle\'的输入自变量未定义函数或方法\'det\'
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我在本主题中描述了相同的问题：
使用fzero：类型为'sym'的输入参数的未定义函数或方法'isfinite'
他们的回答确实帮助了我，但我仍然受困。
我还必须找到w函数的零，该函数的定义步骤如下：
所以唯一的未知数是w，我定义了其他对象，例如：
lambda= @(w) ((16*rho(i)*A(i)*w^2*Lprime(i)^2)/(E(j)*I(i)))^0.25;
beta=@(w) lambda*b(i)^0.5;
gamma=@(w) lambda*Lprime(i)^0.5;
M2=@(w) [besselj(4,beta) bessely(4,beta) besseli(4,beta) besselk(4,beta);
besselj(3,beta) bessely(3,beta) besseli(3,beta) -besselk(3,beta);
besselj(2,gamma) bessely(2,gamma) besseli(2,gamma) besselk(2,gamma);
besselj(4,gamma) bessely(4,gamma) besseli(4,gamma) besselk(4,gamma)];
delta = @(w) det(M2);
S(i,j)=fzero(delta,500);
??? Error using ==> fzero at 235
FZERO cannot continue because user supplied function_handle ==> @(w)det(M2)
failed with the error below.
Undefined function or method \'det\' for input arguments of type \'function_handle\'.
Error in ==> frequencies at 57
S(i,j)=fzero(delta,500);
??? Undefined function or method \'isfinite\' for input arguments of type \'sym\'.
Error in ==> fzero at 323
elseif ~isfinite(fx) || ~isreal(fx)
Error in ==> frequencies at 58
S(i,j)=fzero(@(w) subs(delta,\'w\',w),500);
??? Error using ==> fzero at 307
FZERO cannot continue because user supplied function_handle ==> @(w)eval(delta)
failed with the error below.
Undefined function or method \'eval\' for input arguments of type \'function_handle\'.
Error in ==> frequencies at 59
S(i,j)=fzero(@(w)eval(delta),500);
没有找到相关结果
已邀请:
2 个回复
河饶办斜施
但是，当您在ѭ8use中使用它时，您需要使用的输入值对其进行评估，如下所示：beta = @(w) lambda(w)*b(i)^0.5; %# ^--------------Pass w to lambda to evaluate the functiongamma = @(w) lambda(w)*Lprime(i)^0.5; M2 = @(w) [besselj(4,beta(w)) bessely(4,beta(w)) besseli(4,beta(w)) ... besselk(4,beta(w)); ... besselj(3,beta(w)) bessely(3,beta(w)) besseli(3,beta(w)) ... -besselk(3,beta(w)); ... besselj(2,gamma(w)) bessely(2,gamma(w)) besseli(2,gamma(w)) ... besselk(2,gamma(w)); ... besselj(4,gamma(w)) bessely(4,gamma(w)) besseli(4,gamma(w)) ... besselk(4,gamma(w))]; delta = @(w) det(M2(w));以创建矩阵时，您将使用相同的输入对和进行8次评估！注意，您可以通过在函数中放置并作为输入和两个函数句柄和来进行改进：function newMatrix = M2(w,betaFcn,gammaFcn) bw = betaFcn(w); %# Evaluate the beta function once gw = gammaFcn(w); %# Evaluate the gamma function once newMatrix = [besselj(4,bw) bessely(4,bw) besseli(4,bw) besselk(4,bw); ... besselj(3,bw) bessely(3,bw) besseli(3,bw) -besselk(3,bw); ... besselj(2,gw) bessely(2,gw) besseli(2,gw) besselk(2,gw); ... besselj(4,gw) bessely(4,gw) besseli(4,gw) besselk(4,gw)]; end澳绍能
lambda= @(w) ((16*rho(i)*A(i)*w^2*Lprime(i)^2)/(E(j)*I(i)))^0.25; beta=@(w) lambda(w)*b(i)^0.5; gamma=@(w) lambda(w)*Lprime(i)^0.5; M2=@(w) [besselj(4,beta(w)) bessely(4,beta(w)) besseli(4,beta(w)) besselk(4,beta(w)); besselj(3,beta(w)) bessely(3,beta(w)) besseli(3,beta(w)) -besselk(3,beta(w)); besselj(2,gamma(w)) bessely(2,gamma(w)) besseli(2,gamma(w)) besselk(2,gamma(w)); besselj(4,gamma(w)) bessely(4,gamma(w)) besseli(4,gamma(w)) besselk(4,gamma(w))]; delta = @(w) det(M2(w)); S(i,j)=fzero(@(w) delta(w),500);