Function interp_print_matrix 

fn interp_print_matrix(
    args: &[RValue],
    _named: &[(String, RValue)],
    context: &BuiltinContext<'_>,
) -> Result<RValue, RError>

Print a matrix with row/column labels.

Formats the vector data as a 2D grid using the dim attribute for layout and dimnames for row/column labels.

@param x a matrix to print @return x, invisibly