数据拟合MATLAB实验作业

1、精选优质文档-倾情为你奉上1、 在飞机的机翼加工时, 由于机翼尺寸很大, 通常在图纸上只能标出部分关键点的数据. 某型号飞机的机翼上缘轮廓线的部分数据如下。用插值法求x每改变0.1时的y值，画出图形表示。x 0 4.74 9.05 19 38 57 76 95 114 133 152 171 190y 0 5.23 8.1 11.97 16.15 17.1 16.34 14.63 12.16 6.69 7.03 3.99 0x=0 4.74 9.05 19 38 57 76 95 114 133 152 171 190;y=0 5.23 8.1 11.97 16.15 17.1 16.34 1

2、4.63 12.16 6.69 7.03 3.99 0;cx=0:0.1:190;cy=interp1(x,y,cx,'spline');plot(x,y,'+',cx,cy,x,y,'r:')xlabel('chang'),ylabel('kuang')2、已知观测数据点如表所示：xy0-0.4470.11.9780.23.280.36.160.47.080.57.340.67.660.79.560.89.480.99.3111.2分别用1次和3次多项式函数曲线拟合这些数据点，画出图形。x=0:0.1:1;y=-

3、0.447 1.978 3.28 6.16 7.08 7.34 7.66 9.56 9.48 9.3 11.2;A=polyfit(x,y,1)z=polyval(A,x);plot(x,y,'k+',x,z,'r')x=0:0.1:1;y=-0.447 1.978 3.28 6.16 7.08 7.34 7.66 9.56 9.48 9.3 11.2;A=polyfit(x,y,3)z=polyval(A,x);plot(x,y,'k+',x,z,'r')3、教材P327 习题1cK = 0.0728cKA =0.0731T=6

4、8 68 87 87 106 106 140 140;P=1e+03*97981 13.321 9.0078 13.355 9.7918 14.2779 9.6563 12.463;K=0.0848 0.0897 0.0762 0.0807 0.0696 0.0753 0.0611 0.0651;cT=68:0.5:140;cP=1e+03*9.0078:0.05:1e+03*14.277;cK=griddata(T,P,K,99,1e+03*10.3,'cubic')cKA=griddata(T,P,K,99,1e+03*10.3,'linear')4、教材P327习题4，初始值为V0=0，=0.05x = 5.5577 3.5002f = 6.1490 6.6616 7.4913 8.1147 8.5832 8.9353 9.3987 9.6604f =6.1490 6.6616 7.4913 8.1147 8.5832 8.9353 9.3987 9.6604function f=dianya(x,t)f=10-(10-x(1)*exp(-t/x(2)t=0.5 1 2 3 4 5 7 9;V=6.36 6.48 7.26 8.22 8.66 8.99 9.43