有三个函数,通过excel和minitab作图观察感觉可以用幂函数拟合。求拟合方程。
y=a+b/x^c,最好能给出程序及回归模型。
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第一组为:
x=6.69:0.02:7.53;
y=[4.2,3.7,3.3,2.95,2.63,2.33,2.11,1.87,1.65,1.47,1.32,1.17,1.04,0.925,0.82,0.735,0.653,0.582,0.52,0.462,0.412,0.366,0.325,0.289,0.258,0.23,0.205,0.182,0.162,0.145,0.129,0.115,0.102,0.091,0.081,0.072,0.064,0.057,0.051,0.0455,0.0403,0.036,0.032];
plot(x,y,'+')
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第二组为:
x=6.69:0.02:7.53;
y=[10.2,9.08,8.15,7.3,6.5,5.82,5.19,4.64,4.15,3.72,3.33,2.97,2.65,2.37,2.12,1.9,1.7,1.52,1.36,1.21,1.08,0.97,0.865,0.775,0.69,0.62,0.553,0.493,0.442,0.395,0.353,0.315,0.283,0.253,0.225,0.201,0.18,0.161,0.144,0.129,0.115,0.103,0.092];
plot(x,y,'+')
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第三组为:
x=6.69:0.02:7.53;
y=[17.6,15.7,14.1,12.6,11.2,10.1,9.08,8.1,7.21,6.5,5.8,5.21,4.65,4.17,3.73,3.35,2.99,2.69,2.41,2.15,1.93,1.73,1.54,1.38,1.24,1.11,0.99,0.89,0.795,0.71,0.635,0.57,0.51,0.458,0.409,0.365,0.327,0.293,0.262,0.235,0.21,0.188,0.169];
plot(x,y,'+')
谢谢。