用matlab分别写一段关于含参函数的二次插值和三次插值函数的拟合代码,数据由EXCEL导入,数据总共三列,第一二列为自变量,第三列为因变量。给出自变量与因变量的三维曲面图,真实值和拟合值用不同颜色的点表示,再给出真实值与拟合值的误差图。函数模型为58.38 + 4.11*b(1).x(:,1).^2 * b(2).x(:,2).^(2b(3)),
时间: 2024-03-26 14:42:15 浏览: 58
以下是关于含参函数的二次插值和三次插值函数的拟合代码,数据由Excel导入,数据总共三列,第一二列为自变量,第三列为因变量。给出自变量与因变量的三维曲面图,真实值和拟合值用不同颜色的点表示,再给出真实值与拟合值的误差图。函数模型为58.38 + 4.11*b(1).x(:,1).^2 * b(2).x(:,2).^(2b(3))。
二次插值代码:
```matlab
%导入数据
data = xlsread('data.xlsx');
x = data(:,1); %自变量x
y = data(:,2); %自变量y
z = data(:,3); %因变量z
%构造二次插值函数
f = fit([x, y], z, 'poly22');
%绘制拟合图和真实值图
figure;
plot(f, [x, y], z);
hold on;
scatter3(x, y, z, 'filled', 'MarkerFaceColor', 'b');
xlabel('X');
ylabel('Y');
zlabel('Z');
title('Quadratic Interpolation');
%绘制误差图
figure;
z_pred = feval(f, [x, y]);
scatter3(x, y, z - z_pred, 'filled', 'MarkerFaceColor', 'r');
xlabel('X');
ylabel('Y');
zlabel('Error');
title('Quadratic Interpolation Error');
```
三次插值代码:
```matlab
%导入数据
data = xlsread('data.xlsx');
x = data(:,1); %自变量x
y = data(:,2); %自变量y
z = data(:,3); %因变量z
%构造三次插值函数
f = fit([x, y], z, 'cubicinterp');
%绘制拟合图和真实值图
figure;
plot(f, [x, y], z);
hold on;
scatter3(x, y, z, 'filled', 'MarkerFaceColor', 'b');
xlabel('X');
ylabel('Y');
zlabel('Z');
title('Cubic Interpolation');
%绘制误差图
figure;
z_pred = feval(f, [x, y]);
scatter3(x, y, z - z_pred, 'filled', 'MarkerFaceColor', 'r');
xlabel('X');
ylabel('Y');
zlabel('Error');
title('Cubic Interpolation Error');
```
其中,`data.xlsx` 是存储数据的 Excel 文件,需要与代码文件在同一目录下。
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