>
> but 5 + x is a universal mathematical notation that should be allowed
> to be used regardless of any programming language considerations
>
Actually, it is the other way around. 5+x does not make sense
mathematically if x is a vector, but it is accepted in many programming
language as a broadcasting operation. 5*x and x/5 do make sense when x is a
vector. After a long discussions we decided to try to use the dot notation
consistently for broadcasting operations.
2014-05-02 15:55 GMT+02:00 Hans W Borchers <hwborch...@gmail.com>:
> I have to admit that I am quite unhappy with some of the changed features
> in
> Julia version 0.3.0, especially the 'dot' notation. Here are some examples.
>
>
> Let x be a vector defined as x = [0.1, 0.2, 0.3] . Then typing
>
> julia> 5 + x
> WARNING: x::Number + A::Array is deprecated, use x .+ A instead.
>
> but 5 + x is a universal mathematical notation that should be allowed
> to be used regardless of any programming language considerations.
> On the other hand, both
>
> julia> 5 * x;
> julia> 5 .* x;
>
> work without warning. Why is 5 * x not also deprecated?
>
> If I want to write, e.g., Runge's function in a vectorized form,
>
> julia> runge(x) = 1 ./ (1 .+ 5.*x.^2)
>
> then this looks quite ugly and difficult to grasp on first view.
>
>
> As another example, look at the max / maximum 'dichotomy':
>
> julia> maximum([x, 0.5])
> 0.5
>
> julia> maximum(x, 0.5)
> 3-element Array{Float64,1}:
> 0.1
> 0.2
> 0.3
>
> The first answer looks natural, but I have difficulties understanding the
> meaning of the second case. On the other hand:
>
> julia> max(x, 0.5)
> 3-element Array{Float64,1}:
> 0.5
> 0.5
> 0.5
>
> while max(x, [0.5]) will lead to a dimension error, and max([x, 0.5])
> to a deprecation warning (which I seem to understand why).
>
> I think all this is quite confusing for someone wanting to use Julia mostly
> for technical computing, as the logo promises.
> I am sure this has been discussed before, so probably I missed it. Sorry.
>
>
--
Med venlig hilsen
Andreas Noack Jensen
