normalize

Return normalized vector such that length = 1 and prevent zero-division for zero vector

Information

This information is part of the Modelica Standard Library maintained by the Modelica Association.

Syntax

Vectors.normalize(v);
Vectors.normalize(v,eps=100*Modelica.Constants.eps);

Description

The function call "Vectors.normalize(v)" returns the unit vector "v/length(v)" of vector v. If length(v) is close to zero (more precisely, if length(v) < eps), v/eps is returned in order to avoid a division by zero. For many applications this is useful, because often the unit vector e = v/length(v) is used to compute a vector x*e, where the scalar x is in the order of length(v), i.e., x*e is small, when length(v) is small and then it is fine to replace e by v to avoid a division by zero.

Since the function has the "Inline" annotation, it is usually inlined and symbolic processing is applied.

Example

normalize({1,2,3});  // = {0.267, 0.534, 0.802}
normalize({0,0,0});  // = {0,0,0}

See also

Vectors.length, Vectors.normalizeWithAssert

Syntax

result = normalize(v, eps)

Inputs (2)

v

Type: Real[:]

Description: Real vector

eps

Default Value: 100 * Modelica.Constants.eps

Type: Real

Description: if |v| < eps then result = v/eps

Outputs (1)

result

Type: Real[size(v, 1)]

Description: Input vector v normalized to length=1