c++ - 将 eigen "Transformation"类设置为后/右乘法的主要列

Question

我有一个函数可以对变换矩阵进行大量后乘/右乘。现在我想将此函数转换为使用 Eigen，问题是 Eigen Transformation 类将乘法作为前/左乘法进行。这意味着它在乘法时是行矩阵格式，而存储是列矩阵格式。

有没有办法将 Eigen::Transformation 类成员从行专业更改为列专业？

Answer 1

Eigen 的完整签名 Matrix类是

Matrix<typename Scalar,
       int RowsAtCompileTime,
       int ColsAtCompileTime,
       int Options = 0,
       int MaxRowsAtCompileTime = RowsAtCompileTime,
       int MaxColsAtCompileTime = ColsAtCompileTime>

第 4 个参数 Options 是 described as

Options is a bit field. Here, we discuss only one bit: RowMajor. It specifies that the matrices of this type use row-major storage order; by default, the storage order is column-major. See the page on storage orders. For example, this type means row-major 3x3 matrices

所以你可以说，例如，

Matrix<int, 3, 4, ColMajor> foo;    // column major
Matrix<int, 4, 3, RowMajor> bar;    // row major

More documentation on Storage Orders

如果您指的转换是 Eigen::Transform这还有一个 Options 模板参数，您也可以将其传递给 RowMajor 与 ColMajor。它生成的任何矩阵都将遵循您指定的相同约定。

Transform<typename Scalar,
          int Dim,
          int Mode,
          int _Options = AutoAlign>

同样，_Options 参数被描述为

_Options has the same meaning as in class Matrix. It allows to specify DontAlign and/or RowMajor. These Options are passed directly to the underlying matrix type.