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Absolute Value and Matrix - BruceTTT - 11-04-2013
What does the absolute value do to a matrix argument? For a 2x2 identity matrix it returns the square root of 2. For [[2,0][0,2]] it returns 2 root 2.
Re: Absolute Value and Matrix - Paul Dale - 11-05-2013
Frobenius norm perhaps?
Most likely one of the matrix norms.
- Pauli
Re: Absolute Value and Matrix - Michael de Estrada - 11-05-2013
That's because it returns the Frobenius (Euclidean) norm of the matrix array, which is the square root of the sum of the squares of the matrix elements. So for a 2x2 identity matrix it's sqrt (1^2+1^2) = sqrt (2). In the special case of a 2D or 3D vector, the absolute value is interpreted as the magnitude or length of the vector.
Edited: 5 Nov 2013, 12:12 a.m.
Re: Absolute Value and Matrix - BruceTTT - 11-11-2013
OK, thanks. Do you mean a 1D vector that || interprets as the norm? I see that [3 4] || returns 5.
Also, is there a LIST-> function?
Re: Absolute Value and Matrix - Michael de Estrada - 11-11-2013
I meant a vector in 2D or 3D space, where the values are the coordinates. So it's a 1x2 or 1x3 matrix, which is commonly referred to as a vector. Regardless, it is the SRSS (square-root-of-the-sum-of-the-squares).
As to your second question I'm not sure what you are asking.
Re: Absolute Value and Matrix - Walter B - 11-11-2013
Quote:A 1xn or nx1 matrix is called a vector (of dimension n>1). FYI, a '1D vector' is a (scalar) number.
Do you mean a 1D vector that || interprets as the norm?
d:-)