Absolute Value and Matrix  Printable Version + HP Forums (https://archived.hpcalc.org/museumforum) + Forum: HP Museum Forums (https://archived.hpcalc.org/museumforum/forum1.html) + Forum: Old HP Forum Archives (https://archived.hpcalc.org/museumforum/forum2.html) + Thread: Absolute Value and Matrix (/thread254920.html) 
Absolute Value and Matrix  BruceTTT  11042013 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  11052013 Frobenius norm perhaps? Most likely one of the matrix norms.
Re: Absolute Value and Matrix  Michael de Estrada  11052013 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  11112013 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  11112013 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 (squarerootofthesumofthesquares).
As to your second question I'm not sure what you are asking.
Re: Absolute Value and Matrix  Walter B  11112013
Quote:A 1xn or nx1 matrix is called a vector (of dimension n>1). FYI, a '1D vector' is a (scalar) number.
d:)
