Identify and Remove Duplicate Data in R - Datanovia.
A dimnames attribute for the matrix: NULL or a list of length 2 giving the row and column names respectively. An empty list is treated as NULL, and a list of length one as row names. The list can be named, and the list names will be used as names for the dimensions. x: an R object. additional arguments to be passed to or from methods.
Multiplying a matrix with a vector is a bit of a special case; as long as the dimensions fit, R will automatically convert the vector to either a row or a column matrix, whatever is applicable in that case. You can check for yourself in the following example.
In Eigen, all matrices and vectors are objects of the Matrix template class. Vectors are just a special case of matrices, with either 1 row or 1 column. The first three template parameters of Matrix. The Matrix class takes six template parameters, but for now it's enough to learn about the first three first parameters. The three remaining parameters have default values, which for now we will.
The uppercase versions will work with vectors, which are treated as if they were a 1 column matrix, and are robust if you end up subsetting your data such that R drops an empty dimension. Alternatively, use complete.cases() and sum it (complete.cases() returns a logical vector (TRUE or FALSE) indicating if any observations are NA for any rows.
Efficiently normalize the row or column vectors of a dense or sparse matrix to unit length. rdrr.io Find an R package R language docs Run R in your browser R.
Data frames are handy because real-life data frequently comes in this form: it's very often rectangular, with each row representing one case and the columns representing the observations. Since a data frame is both a list and matrix, we can use either matrix-type extraction or list-type extraction. For example, all four of these produce the same result.
That’s the result, indeed, but the row name is gone now. R tries to simplify the matrix to a vector, if that’s possible. In this case, a single row is returned so, by default, this result is transformed to a vector. If a one-row matrix is simplified to a vector, the column names are used as names for the values. If a one-column matrix is.