在Matlab R2013b中将符号表达式转换为函数句柄 [英] Converting symbolic expression to function handle in Matlab R2013b
问题描述
我正在努力从符号表达式转换我的土木工程项目所需的功能.我需要使用fzero
来找到函数的根.在这里H
应该是变量,我需要找出H
的值.功能就像
I am struggling to convert a function, which I require for my civil engineering project, from symbolic expression. I need to use fzero
to find the root of the function. Here H
should be the variable and I need to find out the value of H
. The function goes like
function x_c = f_x_c(s,H0,VA,Lo,qc,EAo,NF,Sj,Fj)
if (s < 0) || (s > Lo)
disp('The value of s is invalid')
disp(['s = ' num2str(s)]);
return
end
C1 = H/qc;
if NF == 0
n = 0;
sn = 0;
sum_Fj = 0;
end
if NF >= 1
Sj_Q = [0; Sj; Lo];
%Determine n and sn if 0 <= s < Lo:
if s < Lo
STOP = 0;
k = 0;
while STOP == 0
k = k + 1;
if (s >= Sj_Q(k,1)) && (s < Sj_Q((k + 1),1))
STOP = 1;
end
end
n = k - 1;
sn = Sj_Q(k,1);
end
%Determine n and sn if s = Lo:
if s == Lo
n = NF;
sn = Sj(NF,1);
end
sum_Fj = sum(Fj(1:n,1));
end
x_c = (H/EAo)*s;
x_c = x_c + C1*asinh((qc*s - VA + sum_Fj)/H) + ...
- C1*asinh((qc*sn - VA + sum_Fj)/H);
for j = 1:n
sk = Sj_Q((j + 1),1);
sk_1 = Sj_Q(j,1);
sum_Fj = sum(Fj(1:(j - 1)));
x_c = x_c + ...
+ C1*asinh((qc*sk - VA + sum_Fj)/H) + ...
- C1*asinh((qc*sk_1 - VA + sum_Fj)/H);
end
我想在主文件中使用此f_x_c.m
文件,在该文件中我将找到等式的根.
有人可以指导我该怎么做吗?
I want to use this f_x_c.m
file in the main file where I will find the roots of this equation.
Could someone guide me how I can do that?
我尝试使用以下代码进行操作,但未成功.
I have tried doing it using the following code but I wasn't successful.
if (s < 0) || (s > Lo)
disp('The value of s is invalid')
disp(['s = ' num2str(s)]);
return
end
C1 = @(H) (H/qc);
if NF == 0
n = 0;
sn = 0;
sum_Fj = 0;
end
if NF >= 1
Sj_Q = [0; Sj; Lo];
%Determine n and sn if 0 <= s < Lo:
if s < Lo
STOP = 0;
k = 0;
while STOP == 0
k = k + 1;
if (s >= Sj_Q(k,1)) && (s < Sj_Q((k + 1),1))
STOP = 1;
end
end
n = k - 1;
sn = Sj_Q(k,1);
end
%Determine n and sn if s = Lo:
if s == Lo
n = NF;
sn = Sj(NF,1);
end
sum_Fj = sum(Fj(1:n,1));
end
x_c =@(H) (H/EAo)*s;
x_c =@(H) (x_c(H) + (C1(H))*asinh((qc*s - VA + sum_Fj)/H) + ...
- (C1(H))*asinh((qc*sn - VA + sum_Fj)/H));
for j = 1:n
sk = Sj_Q((j + 1),1);
sk_1 = Sj_Q(j,1);
sum_Fj = sum(Fj(1:(j - 1)));
x_c =@(H) (x_c(H) + ...
+ C1(H)*asinh((qc*sk - VA + sum_Fj)/H) + ...
- C1(H)*asinh((qc*sk_1 - VA + sum_Fj)/H));
end
我想在主文件中求解以下方程式:
I want to solve the following equation in the main file:
equation = f_x_c(inext_length, H0, vertical_reaction, inext_length, qc, EAo, NF, hanger_arc_length, point_hanger_force) + 1400;
% Whatever equation f_x_c returns, I have to add another number to it(like here it is 1400), then solve this equation using fzero.
因此,在主文件中,我这样写:
So, in the main file, I wrote like:
equation = @(H) f_x_c(inext_length, H0, vertical_reaction, inext_length, qc, EAo, NF, hanger_arc_length, point_hanger_force);
equation = @(H) (equation(H) + 1400);
answer = fsolve(equation, H0);
推荐答案
对您问题的模拟答案可能类似于
A mock answer to your question probably looks like
function x_c = f_x_c(H,A,B,C,D)
x_c = H*A;
x_c = x_c + B*asinh(C/H) - B*asinh(D/H);
end
而对求解器的调用是
H = fzero(@(H)(f_x_c(H,1,1,1,1)+1400),1);
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