ex5.m

重点内容是计算中的误差、函数方程求根、插值呆逼近、数值积分和微分、线性代数方程组解法、常微分方程初值问题的数值解法、数学软件。

x=[1949,1950,1952,1953,1955,1956,1957,1958,1959,1960,1961,1962,1963,1965,1966,1967,1968,1970,1971,1972,1974,1975,1976,1977,1979,1980,1982,1983,1984];
y=[5.4167,5.5196,5.7428,5.8796,6.1465,6.2828,6.4653,6.5994,6.7209,6.6207,6.5859,6.7297,6.9172,7.2538,7.4542,7.6368,7.8534,8.2992,8.5229,8.7177,9.0859,9.2420,9.3717,9.4974,9.7542,9.8705,10.1541,10.2495,10.3475];
v=1949:1984;
[p1,S1]=polyfit(x,y,2);
[p2,S2]=polyfit(x,y,3);
Q1=S1.normr
Q2=S2.normr
yf1=polyval(p1,v);
yf2=polyval(p2,v);
yf1_1995=polyval(p1,1995)
yf1_2000=polyval(p1,2000)
yf2_1995=polyval(p2,1995)
yf2_2000=polyval(p2,2000)
plot(v,yf1,'r');hold on;
plot(v,yf2,'k')