如何用Matlab做此函数的图形并求最小值function y=fun(x)a=185*(3/(((x(1)^2)/4)+9)^0.5)^0.3if x(1)a y=ksi4+1./k4endfunction ksi1=flow1(x) ksi1=0.591*(1+1697*x(1)^(-1.6))*(100*x(2))^(-0.25*(1+1.986*x(1)^(-0.3))) %x(1)afunction k1
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![如何用Matlab做此函数的图形并求最小值function y=fun(x)a=185*(3/(((x(1)^2)/4)+9)^0.5)^0.3if x(1)a y=ksi4+1./k4endfunction ksi1=flow1(x) ksi1=0.591*(1+1697*x(1)^(-1.6))*(100*x(2))^(-0.25*(1+1.986*x(1)^(-0.3))) %x(1)afunction k1](/uploads/image/z/1978007-23-7.jpg?t=%E5%A6%82%E4%BD%95%E7%94%A8Matlab%E5%81%9A%E6%AD%A4%E5%87%BD%E6%95%B0%E7%9A%84%E5%9B%BE%E5%BD%A2%E5%B9%B6%E6%B1%82%E6%9C%80%E5%B0%8F%E5%80%BCfunction+y%3Dfun%28x%29a%3D185%2A%283%2F%28%28%28x%281%29%5E2%29%2F4%29%2B9%29%5E0.5%29%5E0.3if+x%281%29a+++++y%3Dksi4%2B1.%2Fk4endfunction+ksi1%3Dflow1%28x%29++++++ksi1%3D0.591%2A%281%2B1697%2Ax%281%29%5E%28-1.6%29%29%2A%28100%2Ax%282%29%29%5E%28-0.25%2A%281%2B1.986%2Ax%281%29%5E%28-0.3%29%29%29+++%25x%281%29afunction+k1)
如何用Matlab做此函数的图形并求最小值function y=fun(x)a=185*(3/(((x(1)^2)/4)+9)^0.5)^0.3if x(1)a y=ksi4+1./k4endfunction ksi1=flow1(x) ksi1=0.591*(1+1697*x(1)^(-1.6))*(100*x(2))^(-0.25*(1+1.986*x(1)^(-0.3))) %x(1)afunction k1
如何用Matlab做此函数的图形并求最小值
function y=fun(x)
a=185*(3/(((x(1)^2)/4)+9)^0.5)^0.3
if x(1)a
y=ksi4+1./k4
end
function ksi1=flow1(x)
ksi1=0.591*(1+1697*x(1)^(-1.6))*(100*x(2))^(-0.25*(1+1.986*x(1)^(-0.3))) %x(1)a
function k1=heat1(x)
k1=0.0022*(1+116.9*x(1)^(-0.21))*(100*x(2))^(0.6*(1+0.01133*x(1)^(0.73))) %x(1)a
如何用Matlab做此函数的图形并求最小值function y=fun(x)a=185*(3/(((x(1)^2)/4)+9)^0.5)^0.3if x(1)a y=ksi4+1./k4endfunction ksi1=flow1(x) ksi1=0.591*(1+1697*x(1)^(-1.6))*(100*x(2))^(-0.25*(1+1.986*x(1)^(-0.3))) %x(1)afunction k1
定义的函数有问题改为
function y=fun(x)
a=185*(3/(((x(1)^2)/4)+9)^0.5)^0.3 ;
if x(1)a
y=flow4(x)+1./heat4(x) ;
end
要绘图的话 先给定x的区间,算出y 用plot或plot3(3维图)绘图
最小值可以用min来求或者用fminsearch函数