About diagonal matrices

[José Luis García Pallero]

Hi,
Playing with the new diag() function in octave 3.1.52 I can see some
extrange behaviour (or I don't understand some particular cases). For
example, for the matrix
a = diag([2 3 4])

This is a diagonal matrix: typeinfo(a) -> diagonal matrix
But if I add a scalar: typeinfo(4+a) -> matrix
If I multiply by a scalar: typeinfo(4*a) -> diagonal matrix
But if I multiply by a scalar in element-by-element form: typeinfo(4.*a) ->
matrix
If I divide by a scalar in element-by-element form: typeinfo(4./a) -> matrix
For a power operation: typeinfo(a^2) -> diagonal matrix
But element-by-element: typeinfo(a.^2) -> matrix
For functions: typeinfo(sqrt(a)) -> matrix (the same for sin(), cos(), etc.)

Has any reason for this behaviour?

-- 
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José Luis García Pallero
jgpallero at gmail.com
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Use Debian GNU/Linux and enjoy!
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