示例：Stiffb 和 Stiffr 的增广雅可比矩阵

函数 > 求解和最优化 > 微分方程求解器 > 示例：Stiffb 和 Stiffr 的增广雅可比矩阵

使用 Jacob 函数计算常微分方程 (ODE) 的增广雅可比矩阵，然后将它输入求解器 Stiffb 和 Stiffr。

1. 定义一个具有 4 个未知数的组：

yi 变量为 x 的函数。

2. 定义该组中的常数。

3. 定义初始值。

4. 定义与该组右侧对应的矢量函数 D(x,y)。

5. 使用 augment 函数创建增广雅可比矩阵：

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6. 调用 Stiffb 和 Stiffr 函数：

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返回的矩阵包含 5 列，分别与点数和 4 个未知数的解对应。

7. 从返回的 Stiffb 和 Stiffr 矩阵提取 4 个未知数的解：

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8. 绘制和比较从这两个函数返回的每个未知数的解：

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绘图显示两个 ODE 求解器返回相同的解。