VertexFrame dot_product¶

dot_product(self, left_column_names, right_column_names, dot_product_column_name, default_left_values=None, default_right_values=None)¶

[ALPHA] Calculate dot product for each row in current frame.

Parameters:

Parameters:	left_column_names : list Names of columns used to create the left vector (A) for each row. Names should refer to a single column of type vector, or two or more columns of numeric scalars. right_column_names : list Names of columns used to create right vector (B) for each row. Names should refer to a single column of type vector, or two or more columns of numeric scalars. dot_product_column_name : unicode Name of column used to store the dot product. default_left_values : list (default=None) Default values used to substitute null values in left vector. Default is None. default_right_values : list (default=None) Default values used to substitute null values in right vector. Default is None.
Returns:	: _Unit

left_column_names : list

Names of columns used to create the left vector (A) for each row. Names should refer to a single column of type vector, or two or more columns of numeric scalars.

right_column_names : list

Names of columns used to create right vector (B) for each row. Names should refer to a single column of type vector, or two or more columns of numeric scalars.

dot_product_column_name : unicode

Name of column used to store the dot product.

default_left_values : list (default=None)

Default values used to substitute null values in left vector. Default is None.

default_right_values : list (default=None)

Default values used to substitute null values in right vector. Default is None.

Returns:

: _Unit

Calculate the dot product for each row in a frame using values from two equal-length sequences of columns.

Dot product is computed by the following formula:

The dot product of two vectors $A=[a_1, a_2, ..., a_n]$ and $B =[b_1, b_2, ..., b_n]$ is $a_1*b_1 + a_2*b_2 + ...+ a_n*b_n$ . The dot product for each row is stored in a new column in the existing frame.

Notes

If default_left_values or default_right_values are not specified, any null values will be replaced by zeros.

Examples

Calculate the dot product for a sequence of columns in Frame object my_frame:

>>> my_frame.inspect()

  col_0:int32  col_1:float64  col_2:int32  col3:int32
/-----------------------------------------------------/
  1            0.2            -2           5
  2            0.4            -1           6
  3            0.6             0           7
  4            0.8             1           8
  5            None            2           None

Modify the frame by computing the dot product for a sequence of columns:

>>> my_frame.dot_product(['col_0','col_1'], ['col_2', 'col_3'], 'dot_product')
>>> my_frame.inspect()

  col_0:int32  col_1:float64 col_2:int32 col3:int32  dot_product:float64
/------------------------------------------------------------------------/
  1            0.2           -2          5            -1.0
  2            0.4           -1          6             0.4
  3            0.6            0          7             4.2
  4            0.8            1          8            10.4
  5            None           2          None         10.0

Modify the frame by computing the dot product with default values for nulls:

>>> my_frame.dot_product(['col_0','col_1'], ['col_2', 'col_3'], 'dot_product_2', [0.1, 0.2], [0.3, 0.4])
>>> my_frame.inspect()

  col_0:int32  col_1:float64 col_2:int32 col3:int32  dot_product:float64  dot_product_2:float64
/--------------------------------------------------------------------------------------------/
   1            0.2           -2          5            -1.0               -1.0
   2            0.4           -1          6             0.4                0.4
   3            0.6            0          7             4.2                4.2
   4            0.8            1          8            10.4                10.4
   5            None           2          None         10.0                10.08

Calculate the dot product for columns of vectors in Frame object my_frame:

>>> my_frame.dot_product('col_4', 'col_5, 'dot_product')

col_4:vector  col_5:vector  dot_product:float64
/----------------------------------------------/
 [1, 0.2]     [-2, 5]       -1.0
 [2, 0.4]     [-1, 6]        0.4
 [3, 0.6]     [0,  7]        4.2
 [4, 0.8]     [1,  8]       10.4

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VertexFrame dot_product¶