作业帮高分求matlab程序 进行多项式拟合
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高分求matlab程序 进行多项式拟合
多项式为5项数 即形式为 y=ax^5+bx^4+cx^3+dx^2+ex+f.要得出这种形式的方程.
x=[1978:2002];
y=[272.81,286.43,311.89,324.76,337.07,351.81,390.85,466.75,490.86,545.46,648.3,696.54,781.66,893.77,1114.32,1519.23,1990.66,2499.43,2957.55,3438.79,3801.09,4188.73,4771.17,5210.12,5741.03]
还要得出拟合的多项式！我要式子！
多项式为5项数 即形式为 y=ax^5+bx^4+cx^3+dx^2+ex+f.要得出这种形式的方程.
x=[1978:2002];
y=[272.81,286.43,311.89,324.76,337.07,351.81,390.85,466.75,490.86,545.46,648.3,696.54,781.66,893.77,1114.32,1519.23,1990.66,2499.43,2957.55,3438.79,3801.09,4188.73,4771.17,5210.12,5741.03]
还要得出拟合的多项式！我要式子！
x=1978:2002;
y=[272.81,286.43,311.89,324.76,337.07,351.81,390.85,466.75,490.86,545.46,648.3,696.54,781.66,893.77,1114.32,1519.23,1990.66,2499.43,2957.55,3438.79,3801.09,4188.73,4771.17,5210.12,5741.03];
p = polyfit(x,y,5);
f = polyval(p,x);
plot(x,y,'o',x,f,'-');
p
以上是程序,结果为：
p =
1.0e+014 *（ -0.0000 0.0000 -0.0000 0.0000 -0.0027 1.0632）
依次即为abcdef.
不过这些数据不适合用5次拟合,2或3次就够了.5次拟合的数据,可能因为条件数差而不准确.
y=[272.81,286.43,311.89,324.76,337.07,351.81,390.85,466.75,490.86,545.46,648.3,696.54,781.66,893.77,1114.32,1519.23,1990.66,2499.43,2957.55,3438.79,3801.09,4188.73,4771.17,5210.12,5741.03];
p = polyfit(x,y,5);
f = polyval(p,x);
plot(x,y,'o',x,f,'-');
p
以上是程序,结果为：
p =
1.0e+014 *（ -0.0000 0.0000 -0.0000 0.0000 -0.0027 1.0632）
依次即为abcdef.
不过这些数据不适合用5次拟合,2或3次就够了.5次拟合的数据,可能因为条件数差而不准确.