用matlab-最速下降法-解方程组,四个未知数:a,b,c,d,我弄了好久没弄出来.方程组:[77.6*(1/a+(1-exp(-0.5*b/d))/b+0.5/c)=8;77.6*(1/a+(1-exp(-b/d))/b+1/c)=9;77.6*(1/a+(1-exp(-1.75*b/d))/b+1.75/c)=10;77.6*(1/a+(1-exp(-4.25*b/d))/b
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![用matlab-最速下降法-解方程组,四个未知数:a,b,c,d,我弄了好久没弄出来.方程组:[77.6*(1/a+(1-exp(-0.5*b/d))/b+0.5/c)=8;77.6*(1/a+(1-exp(-b/d))/b+1/c)=9;77.6*(1/a+(1-exp(-1.75*b/d))/b+1.75/c)=10;77.6*(1/a+(1-exp(-4.25*b/d))/b](/uploads/image/z/6834783-39-3.jpg?t=%E7%94%A8matlab-%E6%9C%80%E9%80%9F%E4%B8%8B%E9%99%8D%E6%B3%95-%E8%A7%A3%E6%96%B9%E7%A8%8B%E7%BB%84%2C%E5%9B%9B%E4%B8%AA%E6%9C%AA%E7%9F%A5%E6%95%B0%EF%BC%9Aa%2Cb%2Cc%2Cd%2C%E6%88%91%E5%BC%84%E4%BA%86%E5%A5%BD%E4%B9%85%E6%B2%A1%E5%BC%84%E5%87%BA%E6%9D%A5.%E6%96%B9%E7%A8%8B%E7%BB%84%EF%BC%9A%5B77.6%2A%281%2Fa%2B%281-exp%28-0.5%2Ab%2Fd%29%29%2Fb%2B0.5%2Fc%29%3D8%3B77.6%2A%281%2Fa%2B%281-exp%28-b%2Fd%29%29%2Fb%2B1%2Fc%29%3D9%3B77.6%2A%281%2Fa%2B%281-exp%28-1.75%2Ab%2Fd%29%29%2Fb%2B1.75%2Fc%29%3D10%3B77.6%2A%281%2Fa%2B%281-exp%28-4.25%2Ab%2Fd%29%29%2Fb)
用matlab-最速下降法-解方程组,四个未知数:a,b,c,d,我弄了好久没弄出来.方程组:[77.6*(1/a+(1-exp(-0.5*b/d))/b+0.5/c)=8;77.6*(1/a+(1-exp(-b/d))/b+1/c)=9;77.6*(1/a+(1-exp(-1.75*b/d))/b+1.75/c)=10;77.6*(1/a+(1-exp(-4.25*b/d))/b
用matlab-最速下降法-解方程组,四个未知数:a,b,c,d,我弄了好久没弄出来.
方程组:
[77.6*(1/a+(1-exp(-0.5*b/d))/b+0.5/c)=8;
77.6*(1/a+(1-exp(-b/d))/b+1/c)=9;
77.6*(1/a+(1-exp(-1.75*b/d))/b+1.75/c)=10;
77.6*(1/a+(1-exp(-4.25*b/d))/b+4.25/c)=11];
最好有matlab的M文件或程序.
用matlab-最速下降法-解方程组,四个未知数:a,b,c,d,我弄了好久没弄出来.方程组:[77.6*(1/a+(1-exp(-0.5*b/d))/b+0.5/c)=8;77.6*(1/a+(1-exp(-b/d))/b+1/c)=9;77.6*(1/a+(1-exp(-1.75*b/d))/b+1.75/c)=10;77.6*(1/a+(1-exp(-4.25*b/d))/b
你得给一个初值,初值不合适的话就解不出来.
程序如下,修改x0就是修改初值了.运行会有个警告,表示迭代次数达到最大.
% 程序开始 test_fsolve.m
function test_fsolve
x0 = [1; 1; 1; 1]*1e-3;
xx = fsolve(@eqns,x0)
function y = eqns(x)
[a,b,c,d]=deal(x(1),x(2),x(3),x(4));
y = zeros(4,1);
y(1) = 77.6*(1/a+(1-exp(-0.5*b/d))/b+0.5/c)-8;
y(2) = 77.6*(1/a+(1-exp(-b/d))/b+1/c)-9;
y(3) = 77.6*(1/a+(1-exp(-1.75*b/d))/b+1.75/c)-10;
y(4) = 77.6*(1/a+(1-exp(-4.25*b/d))/b+4.25/c)-11;
% 程序结束 test_fsolve.m