Is there a need to use the “.” for vector math when adding and multiplying? a = [1 2 3] b = [3 4 5] # Which is better for performance? They both do the same thing. c = 1/2 * a + b d = 1/2 .* a .+ b

The second should be about 2x faster. The second will compile to roughly d=Vector{Float64}(undef, length(a)) for i in eachindex(a,b) d[i] = .5*a[i]+b[i] end while the first will use 2 loops and allocate an intermediate vector. If you don’t want to have ot use lots of dots, you could write thi…

Vectorized math

General Usage Performance

lancejnelson February 17, 2021, 7:09pm 7

You’re not saying that this:

c = 1/2 * a .+ b

will be as fast as this:

c = 1/2 .* a .+ b

are you?

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