c++ - 特征值:从 vector 中减去标量

Question

我在使用 Eigen 库时遇到错误，我想做的就是从 Eigen::VectorXf 中减去一个标量。所以，我的代码如下:

#define VECTOR_TYPE Eigen::VectorXf
#define MATRIX_TYPE Eigen::MatrixXf

// myMat is of MATRIX_TYPE
JacobiSVD<MATRIX_TYPE> jacobi_svd(myMat,ComputeThinU | ComputeThinV); 

const float offset = 3.0f;
VECTOR_TYPE singular_values = jacobi_svd.singularValues();

VECTOR_TYPE test = singular_values - offset;

最后一行导致编译错误:

error: invalid operands to binary expression ('Eigen::VectorXf' (aka 'Matrix') and 'float') VECTOR_TYPE test = singular_values - scale;

Eigen/src/Core/../plugins/CommonCwiseBinaryOps.h:19:28: note: candidate template ignored: could not match 'MatrixBase' against 'float' EIGEN_MAKE_CWISE_BINARY_OP(operator-,internal::scalar_difference_op)

Answer 1

最简单的是移动到所谓的"array"。世界:

VECTOR_TYPE test = singular_values.array() - offset;