CODEWITHSUNDEEP
c++eigen
mariya
mariya

Reputation: 127

How to add a vector to each row in eigen?

I am trying to add a vector to each row in a matrix, but I am getting error.

Here is the code:

MatrixXd shifted_cord = MatrixXd::Random(10,3);
Vector3d v = Vector3d(3.0,20.0,0.0);
//std::cout<<shifted_cord<<std::endl;
shifted_cord = shifted_cord.colwise()+v;  //(10,3)

I need to shift all rows, in this case 10.

Same thing is done in this, but when I tried, I am getting error.

Error:

Assertion `aLhs.rows() == aRhs.rows() && aLhs.cols() == aRhs.cols()' failed.

Can anyone help me with this error?

Upvotes: 3

Views: 3114

Answers (1)

chtz
chtz

Reputation: 18827

If you want to add to each row, you need to write .rowwise() and make sure that the vector you add is indeed a row-vector (either declare v as RowVector3d, or write v.transpose(). Also you can use the += operator with .rowwise() expressions:

shifted_cord = shifted_cord.rowwise()+v.transpose();
// or
shifted_cord.rowwise()+=v.transpose();

Upvotes: 4

Related Questions