slice#

swordfish.function.slice()#

For slice(obj, index):

  • If obj is an array vector and

    • index is a scalar, it returns a vector indicating a column;

    • index is a vector, it returns an array vector of selected rows;

    • index is a pair, it returns an array vector of selected columns.

  • If obj is a matrix and

    • index is a scalar, it returns a vector indicating a column.

    • index is a vector or a pair, it returns a matrix of selected columns.

  • If obj is a table and

    • index is a scalar, it returns a dictionary indicating a row.

    • index is a vector or a pair, it returns a table of selected rows.

For slice(obj, rowIndex, [colIndex]):

  • If obj is an array vector and

    • rowIndex and colIndex are both scalars, it returns a vector indicating a column;

    • rowIndex is a scalar and colIndex is a pair (or vise versa), it returns an array vector of selected rows and columns;

    • rowIndex and colIndex are both pair, it returns an array vector of selected rows and columns.

  • If obj is a matrix and

    • rowIndex and colIndex are both scalars, it returns a scalar indicating the value of specified element of the matrix.

    • rowIndex is a scalar and colIndex is a pair (or vise versa), it returns a submatrix of selected rows and columns.

    • rowIndex and colIndex are both vectors or pairs, it returns a submatrix of selected rows and columns.

  • If obj is a table and

    • rowIndex and colIndex are both scalars, return a scalar indicating the value of specified element of the table.

    • rowIndex is a scalar and colIndex is a pair (or vise versa), it returns a table of selected rows and columns.

    • rowIndex and colIndex are both vectors or pairs, it returns a table of selected rows and columns.

Note

  • To get a particular row or column from a table, consider using function col or row.

  • When index, rowIndex or colIndex specifies the index range of an array vector or a matrix, if the values are not within [0, size(X)-1], the corresponding results are null values.

Parameters:

  • obj (Constant) – Can be an array vector, a matrix or a table.

  • index (Union[Alias[Literal["rowIndex"]], Constant]) – Can be scalar/vector/pair indicating the row index. If index, rowIndex is a pair, it indicates the range of index which is left-closed and right-open.

  • colIndex (Constant, optional) – Can be scalar/vector/pair indicating the column index, by default DFLT. If colIndex is a pair, it indicates the range of index which is left-closed and right-open.

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