VECTOR_MAGNITUDE

Calculates the magnitude of an n-dimensional vector. The magnitude of a vector is its length expressed as a positive scalar.

Behavior type

Immutable

Syntax

VECTOR_MAGNITUDE( vector_arr )

Arguments

vector_arr: N-dimensional vector, type ARRAY of INT, FLOAT, NUMERIC

Note

NULL and NaN values are treated equivalently. If any element in the input array is NULL or NaN, the function returns NULL.

Returns

FLOAT

Examples

The following example computes the vector magnitude for two input arrays using two function calls of VECTOR_MAGNITUDE():

SELECT id, vector_arr1, VECTOR_MAGNITUDE(vector_arr1) AS mag1, vector_arr2, VECTOR_MAGNITUDE(vector_arr2) AS mag2
FROM vectors_array;
id |  vector_arr1  |      mag1         |  vector_arr2  |     mag2      
----+---------------+------------------+---------------+------------------
  1 | [1.0,2.0,3.0] | 3.74165738677394 | [4.0,5.0,6.0] | 8.77496438739212
  2 | [1.5,2.5,3.5] | 4.55521678957215 | [4.5,5.5,6.5] | 9.63068014212911
  3 | [0.0,1.0,0.0] |                1 | [0.0,0.0,1.0] |                1
  4 | [2.0,0.0,0.0] |                2 | [0.0,2.0,0.0] |                2
  5 | [1.0,1.0,1.0] | 1.73205080756888 | [1.0,1.0,1.0] | 1.73205080756888
(5 rows)

The following example computes the vector magnitude for a 5D vector:

SELECT VECTOR_MAGNITUDE(Array[1.0, 2.0, 3.0, 4.0, 5.0]);
VECTOR_MAGNITUDE   
------------------
7.41619848709566
(1 row)