作业帮已知坐标 matlab拟合曲线
来源：学生作业帮 编辑：拍题作业网作业帮 分类：综合作业 时间：2024/04/28 16:44:50
已知坐标 matlab拟合曲线
X=[-21.89,-21.73,-21.58,-21.42,-21.42,-21.40,-21.36,-21.28,-21.18,-21.07,-20.90,-20.72,-20.54,-20.41,-20.26,-20.10,-19.95,-19.81,-19.70,-19.60,-19.50,-19.39,-19.27,-19.09,-18.88,-18.67,-18.50,-18.32,-18.09,-17.79,-17.42,-17.06,-16.75,-16.43,-16.11,-15.77,-15.44,-15.12,-14.80,-14.46,-14.07,-13.67,-13.27,-12.91,-12.42,-11.79,-11.15,-10.57,-10.08,-9.60,-9.17,-8.79,-8.38,-7.93,-7.46,-6.96,-6.55,-6.20,-5.89,-5.37,-4.62,-3.61,-2.61,-1.81,-1.18,-0.69,-0.18,0.37,0.87,1.36,1.80,2.46,3.29,4.27,5.23,5.97,6.58,7.04,7.54,7.95,8.31,8.62,8.94,9.33,9.76,10.20,10.64,11.06,11.61,12.27,12.89,13.39,13.76,14.13,14.43,14.66,14.82,14.99,15.18,15.38,15.59,15.76,15.94,16.15,16.44,16.75,17.03,17.30,17.53,17.77,18.02,18.28,18.55,18.80,19.04,19.24,19.45,19.64,19.82,19.98,20.11,20.23,20.37,20.49,20.61,20.77,20.98,21.18,21.33,21.41,21.44,21.44,21.48,21.56,21.69,21.81,21.89,21.93];
Y=[48.82,49.23,49.64,50.05,50.05,50.14,50.36,50.69,51.08,51.51,52.13,52.82,53.46,53.93,54.34,54.74,55.10,55.40,55.64,55.90,56.13,56.39,56.70,57.06,57.45,57.78,58.06,58.34,58.72,59.24,59.85,60.41,60.84,61.23,61.59,61.99,62.39,62.77,63.12,63.44,63.77,64.11,64.46,64.77,65.20,65.68,66.09,66.42,66.70,66.98,67.23,67.42,67.61,67.78,67.95,68.14,68.30,68.43,68.54,68.70,68.90,69.09,69.25,69.34,69.37,69.38,69.37,69.37,69.37,69.37,69.34,69.27,69.16,68.98,68.76,68.53,68.30,68.12,67.93,67.78,67.64,67.51,67.35,67.15,66.90,66.65,66.41,66.16,65.82,65.35,64.82,64.37,64.05,63.72,63.47,63.26,63.10,62.91,62.70,62.46,62.21,62.01,61.80,61.56,61.24,60.87,60.49,60.09,59.72,59.30,58.88,58.42,57.98,57.57,57.16,56.76,56.28,55.82,55.39,55.06,54.76,54.47,54.10,53.71,53.25,52.64,51.87,51.10,50.48,50.10,49.93,49.93,49.84,49.66,49.39,49.11,48.91,48.80];
这是我的x,y坐标，需要拟合出y的曲线方程式麻烦大家了；谢谢最好把matlab程序也给我写一下！。
麻烦各位把曲线方程给我一个行么？误差最好不大于0.5.谢谢了！！！我是初学者，为什么我拟合出来的方程y=-0.0001x4-0.0127x2+68.9763，虽然拟合出来的曲线是对的。但是将x坐标值带入方程得出的y值却不对呢！呵呵！
X=[-21.89,-21.73,-21.58,-21.42,-21.42,-21.40,-21.36,-21.28,-21.18,-21.07,-20.90,-20.72,-20.54,-20.41,-20.26,-20.10,-19.95,-19.81,-19.70,-19.60,-19.50,-19.39,-19.27,-19.09,-18.88,-18.67,-18.50,-18.32,-18.09,-17.79,-17.42,-17.06,-16.75,-16.43,-16.11,-15.77,-15.44,-15.12,-14.80,-14.46,-14.07,-13.67,-13.27,-12.91,-12.42,-11.79,-11.15,-10.57,-10.08,-9.60,-9.17,-8.79,-8.38,-7.93,-7.46,-6.96,-6.55,-6.20,-5.89,-5.37,-4.62,-3.61,-2.61,-1.81,-1.18,-0.69,-0.18,0.37,0.87,1.36,1.80,2.46,3.29,4.27,5.23,5.97,6.58,7.04,7.54,7.95,8.31,8.62,8.94,9.33,9.76,10.20,10.64,11.06,11.61,12.27,12.89,13.39,13.76,14.13,14.43,14.66,14.82,14.99,15.18,15.38,15.59,15.76,15.94,16.15,16.44,16.75,17.03,17.30,17.53,17.77,18.02,18.28,18.55,18.80,19.04,19.24,19.45,19.64,19.82,19.98,20.11,20.23,20.37,20.49,20.61,20.77,20.98,21.18,21.33,21.41,21.44,21.44,21.48,21.56,21.69,21.81,21.89,21.93];
Y=[48.82,49.23,49.64,50.05,50.05,50.14,50.36,50.69,51.08,51.51,52.13,52.82,53.46,53.93,54.34,54.74,55.10,55.40,55.64,55.90,56.13,56.39,56.70,57.06,57.45,57.78,58.06,58.34,58.72,59.24,59.85,60.41,60.84,61.23,61.59,61.99,62.39,62.77,63.12,63.44,63.77,64.11,64.46,64.77,65.20,65.68,66.09,66.42,66.70,66.98,67.23,67.42,67.61,67.78,67.95,68.14,68.30,68.43,68.54,68.70,68.90,69.09,69.25,69.34,69.37,69.38,69.37,69.37,69.37,69.37,69.34,69.27,69.16,68.98,68.76,68.53,68.30,68.12,67.93,67.78,67.64,67.51,67.35,67.15,66.90,66.65,66.41,66.16,65.82,65.35,64.82,64.37,64.05,63.72,63.47,63.26,63.10,62.91,62.70,62.46,62.21,62.01,61.80,61.56,61.24,60.87,60.49,60.09,59.72,59.30,58.88,58.42,57.98,57.57,57.16,56.76,56.28,55.82,55.39,55.06,54.76,54.47,54.10,53.71,53.25,52.64,51.87,51.10,50.48,50.10,49.93,49.93,49.84,49.66,49.39,49.11,48.91,48.80];
这是我的x,y坐标，需要拟合出y的曲线方程式麻烦大家了；谢谢最好把matlab程序也给我写一下！。
麻烦各位把曲线方程给我一个行么？误差最好不大于0.5.谢谢了！！！我是初学者，为什么我拟合出来的方程y=-0.0001x4-0.0127x2+68.9763，虽然拟合出来的曲线是对的。但是将x坐标值带入方程得出的y值却不对呢！呵呵！
直接用plot(X,Y)得到X和Y的关系图
在此图中菜单栏里找到Tools—Basic Fitting
里面有很多拟和的方法
若用4次多项式拟和可以得到
y=-5.9275e-005*x^4-3.345e-006*x^3-0.012688*x^2+3.7124e-005*x+68.976
其拟和残差为4.5098，拟和效果已经可以了
也可以试试其中的其他拟和方法
在此图中菜单栏里找到Tools—Basic Fitting
里面有很多拟和的方法
若用4次多项式拟和可以得到
y=-5.9275e-005*x^4-3.345e-006*x^3-0.012688*x^2+3.7124e-005*x+68.976
其拟和残差为4.5098，拟和效果已经可以了
也可以试试其中的其他拟和方法