That would be the 'length'
Hello I read the following equation
Imageshack - log.gif
but I do not understand what the
|| (what ever is inside) ||2 (with the 2 as a small number -- called index?)
could you please help me understand what this is about?
I would like to thank you in advance for your help
is a notation that represents the "length" of a vector . In your expression, is the vector whose length is being calculated.
Since "length" can be defined in a number of ways, the subscript indicates that the length is calculated using the Euclidean norm. So, means that you should find the length of the vector as defined by the Euclidean norm.
The Euclidean norm is the most intuitive definition of length. For example, if you have a vector , its Euclidean length would be . You can conceptualize this as the distance between the point and the origin.
What is so "hard" about that notation?
What level text was this? There is usually a list of symbols, either in the very front or very back of the text book for an introductory text. In a more advanced text, of course, you would be expected to already know standard notation.