bigframes.pandas.DataFrame.dot

DataFrame.dot(other: _DataFrameOrSeries) → _DataFrameOrSeries

Compute the matrix multiplication between the DataFrame and other.

This method computes the matrix product between the DataFrame and the values of an other Series or DataFrame.

It can also be called using self @ other.

Note

The dimensions of DataFrame and other must be compatible in order to compute the matrix multiplication. In addition, the column names of DataFrame and the index of other must contain the same values, as they will be aligned prior to the multiplication.

Note

The dot method for Series computes the inner product, instead of the matrix product here.

Examples:

>>> left = bpd.DataFrame([[0, 1, -2, -1], [1, 1, 1, 1]])
>>> left
   0  1   2   3
0  0  1  -2  -1
1  1  1   1   1

[2 rows x 4 columns]
>>> right = bpd.DataFrame([[0, 1], [1, 2], [-1, -1], [2, 0]])
>>> right
    0   1
0   0   1
1   1   2
2  -1  -1
3   2   0

[4 rows x 2 columns]
>>> left.dot(right)
   0  1
0  1  4
1  2  2

[2 rows x 2 columns]

You can also use the operator @ for the dot product:

>>> left @ right
   0  1
0  1  4
1  2  2

[2 rows x 2 columns]

The right input can be a Series, in which case the result will also be a Series:

>>> right = bpd.Series([1, 2, -1,0])
>>> left @ right
0    4
1    2
dtype: Int64

Any user defined index of the left matrix and columns of the right matrix will reflect in the result.

>>> left = bpd.DataFrame([[1, 2, 3], [2, 5, 7]], index=["alpha", "beta"])
>>> left
       0  1  2
alpha  1  2  3
beta   2  5  7

[2 rows x 3 columns]
>>> right = bpd.DataFrame([[2, 4, 8], [1, 5, 10], [3, 6, 9]], columns=["red", "green", "blue"])
>>> right
   red  green  blue
0    2      4     8
1    1      5    10
2    3      6     9

[3 rows x 3 columns]
>>> left.dot(right)
       red  green  blue
alpha   13     32    55
beta    30     75   129

[2 rows x 3 columns]

Parameters:

other (Series or DataFrame) – The other object to compute the matrix product with.

Returns:

If other is a Series, return the matrix product between self and other as a Series. If other is a DataFrame, return the matrix product of self and other in a DataFrame.

Return type:

bigframes.pandas.DataFrame or bigframes.pandas.Series

Raises:

RuntimeError – If unable to construct all columns.