The Julia Language

This doesn't seem right:

julia> println.(stdout, [1,2,3])
ERROR: MethodError: no method matching length(::Base.TTY)
Closest candidates are:
  length(::Union{Base.KeySet, Base.ValueIterator}) at abstractdict.jl:58
  length(::Union{LinearAlgebra.Adjoint{T, S}, LinearAlgebra.Transpose{T, S}} where {T, S}) at /Users/julia/buildbot/worker/package_macos64/build/usr/share/julia/stdlib/v1.6/Li

In recent versions (can't say from exactly when), there seems to be an off-by-one error in dcc.DatePickerRange. I set max_date_allowed = datetime.today().date(), but in the calendar, yesterday is the maximum date allowed. I see it in my apps, and it is also present in the first example on the DatePickerRange documentation page.

E

When I save any of my notebooks as HTML in Safari, the output file is always called true.html. The name of the output file is correct in Chrome, though.

• MacOS 10.15.7
• Safari 14.1.2
• Pluto v0.15.1
• Julia 1.7.0-beta3.0

The error message below is not friendly or helpful for new users. (It came up on Discourse, and it is one of the more frequent questions we get asked.)

Perhaps something like:

`MOI.ScalarQuadraticFunction{Float64}`-in-`MOI.EqualTo{Float64}` constraints are
not supported by this solver.

If you expected the solve

Details

(This is related to JuliaPlots/Plots.jl#1706)

For example scatter(skipmissing([1.0, 2.0, missing, 1.0])) fails with Cannot convert Base.SkipMissing{Vector{Union{Missing, Float64}}} to series data for plotting.

Generally skipmissing is not required but it seems odd to see this fail.

Also I stumbled on this while trying to make a histogram, e.g.

The following code gives a segfault with Makie 0.15 and Julia 1.6.1 (also reproduced with 1.7-beta2):

using Makie

xs = range(150, 160, length=100)
ys = range(7, 9, length=100)
points = [(x, y, 0.0) for x in xs for y in ys]
x, y, z = map(i -> getindex.(points, i), 1:3)

flags = (153 .< x .< 153.5) .& (7 .< y .< 7.3)
surface(y[flags], x[flags], z[flags]);

Starting Julia

I found that function mod2pi is not implemented yet, but mod works. Is there any list of implemented functions? Minimal working example is:

using Zygote

# This is working
gradient(x -> mod(x, 2pi), 1.)

# This is not
gradient(x -> mod2pi(x), 1.)

In Exercises 10.1, the outer product in Take the outer product of a vector v with itself and assign it to variable cross_v should be cross product.

The basics of DiscreteSystem exists now, but the little details around it need to be finished.