matrixlijn
Matrixlijn is not a standard term in formal Dutch mathematics. In many cases it is used informally to refer to a line or a row within a matrix, or to a row vector, but the precise, commonly accepted terms are different.
In standard terminology, a matrix is a two-dimensional array of numbers. Its horizontal slices are called rows
If the intended meaning of matrixlijn is a geometric line, then that concept belongs to Euclidean geometry
Examples help: for A = [[1, 2, 3], [4, 5, 6]], the first row is (1, 2, 3)
Summary: matrixlijn is not a standard technical term; use rij (row) or rijvector for a horizontal slice,