%%步長(zhǎng)加速法
clear
clc
xm1=[0?3]‘;
s=0.04;??%/精度
r=1.2;???%加速因子
a=0.5;?%初始步長(zhǎng)
sj=0.2;
e1=[1?0]‘;
e2=[0?1]‘;
syms?x1
syms?x2
f=（x1-2）^4+（x1-2*x2）^2;
%探測(cè)移動(dòng)
????%e1方向搜索
y1=xm1;
y01=y1+a*e1;
fx1=subs（f{x1?x2}{y1（11）y1（21）}）;
fy01=subs（f{x1?x2}{y01（11）y01（21）}）;
if?fy01<=fx1
????y2=y01;
else
????y02=y1-a*e1;
????fy02=subs（f{x1?x2}{y02（11）y02（21）}）;
????if?fy02<=fx1
????????y2=y02;
????else
????????y2=y1;
????end
end
????%e2方向搜索
y03=y2+a*e1;
fy2=subs（f{x1?x2}{y2（11）y2（21）}）;
fy03=subs（f{x1?x2}{y03（11）y03（21）}）;
if?fy03<=fy2
????y3=y03;
else
????y04=y2-a*e1;
????fy04=subs（f{x1?x2}{y04（11）y04（21）}）;
????if?fy04<=fy2
????????y3=y04;
????else
????????y3=y2;
????end
end
%模式搜索
fy3=subs（f{x1?x2}{y3（11）y3（21）}）;
xm2=y3;
c=a*sj;
t=1;?%迭代次數(shù)
while?c>=s
????if?fy3<=fx1
????????y1=xm2+r*（xm2-y1）;
????else
????????a=sj*a;