I am trying to use unit test to test the equality of two arrays, wheres the following test: @test [2.36248e-314, 2.36248e-314] ≈ [0.0, 0.0] would fail. The two entries in the vector, if compared separately with the same method, would pass the equality test. Is there an extended unit test for equal…

[image] fufjvnvnf: The two entries in the vector, if compared separately with the same method, would pass the equality test. What do you mean here? julia> 2.36248e-314 ≈ 0.0 false

[image] fufjvnvnf: Is there an extended unit test for equality for arrays in julia? There is (although as @kristoffer.carlsson pointed out, the two arguments are not \approx individually). You can see which method is being called for any function call in Julia with @which: julia> @which [2.3…

To just test elementwise you could use dot syntax julia> [1.0, 1e9] ≈ [0.0, 1e9] true julia> all([1.0, 1e9] .≈ [0.0, 1e9]) false

If you want to test that an array is approximately zero, you need to either pass an absolute tolerance (atol keyword) to isapprox (you can also do @test x ≈ y atol=sometolerance in 0.7) or just test norm(x) ≤ sometolerance. Without an atol keyword, ≈ only tests that the relative error is small, and…

I am actually surprised by this. I tested with 0.9999999999 and 1, which returns true, so I thought there is some default tolerance for equality testing.

As Steven described, there exists a default relative tolerance. Copying the docstring here: isapprox(x, y; rtol::Real=sqrt(eps), atol::Real=0, nans::Bool=false, norm::Function) Inexact equality comparison: true if norm(x-y) <= atol + rtol*max(norm(x), norm(y)). The default atol is zero and the…

Why didn’t isapprox(x::AbstractArray, y::AbstractArray) disappear as part of the . broadcasting deprecations?

Because it does something different from the dotted version. Similar reason why *(::Matrix, ::Matrix) didn’t get removed.

I came across this thread after struggling to make sense out of tests for array elements. It might be worth explicating in the docs. It appears that @test all(isapprox.(x, y, atol=0.05)) is the correct syntax (I couldn’t find anything simpler). One problem is @test isapprox(x, y, atol=0.05) passes …

As noted by Kristoffer Carlsson above, isapprox(a, b) compares under some norm determined by the arguments. It is different from all(isapprox.(a, b)) It is really up to the user to select the best comparison — either one could be useful in some context. It is important to note that a custom nor…

Unit test equality for arrays?

General Usage

tinosulzer April 22, 2021, 5:28pm 15

Ok, makes sense

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Unit test equality for arrays?

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