Order of arguments in mutating functions
I’m sure this has been asked before, but my searches came up empty. I have a function F that takes another function f and an array A as input. The function mutates A. So is the order F!(f,A) or...
View ArticleUnexpect results constructing a DArray
I have been playing with DistributedArrays recently and found the following result: r1 = @spawnat 2 ones(Int64, 3, 2) r2 = @spawnat 3 fill(5, (3,2)) r3 = @spawnat 2 fill(9, (3,2)) r4 = @spawnat 3...
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How do I get an almost "normal" normal distribution?
Sorry for the “normal” normal . What I mean is that I need a Gaussian distribution with a slight change. I need to include a factor \xi, such as the density distribution below I don’t need the best...
View ArticleInstall Plots: ERROR: KeyError: key "Zlib_jll" not found
Fresh install and fresh active project… (Julia) pkg> add Plots Resolving package versions… ERROR: KeyError: key “Zlib_jll” not found Any Ideas? 6 posts - 2 participants Read full topic
View ArticleTaking derivative of abstract function pattern in sympy
I want to compute a derivative of an expression involving an abstract function like xg(x) or the mixed partial of xg(x)/(g(x)+g(y)). Based on the original python docs here, I tried: using SymPy x =...
View ArticleHow to get a function to print stuff with REPL-like formatting
Sometimes it’s easier if what gets printed by a function looks nice (like in the REPL): function printout(x) println("x is: ",x) end Ex 1. Beautiful formatting that can be instantly read and...
View ArticleSecond plot series send to background
Is it possible to send a second plot (e.g. a vertical line) to the background? I know, if I drew the vertical line first, I would get what I want. However, then I have to provide axis scales in order...
View ArticleA simple macro to transform `newcol = fn(:col)` to `:col => fn => :newcol`;...
In DataFrames.jl there are a number of places where you have use this syntax :col => fn => :newcol to compute new columns. This makes sense once you get used to it, but sometimes you want a...
View ArticlePyJulia, passing numpy array from Python side
I’m looking into extending Python with Julia code through PyJulia, particularly allocating numpy arrays in Python, passing them to Julia (without copying) to do some processing and then use the result...
View ArticleFastest way to broadcast reductions of SubArrays
I have an array arr whose subarrays correspond to the column-groups given in colinds. Below is an example of division that does what I want without creating any subarrays or broadcasting. The desired...
View ArticleHow to locate in which package a certain function belongs
How to locate in which package a certain function belongs. For example I am interested in finding the package for the function integrate_ODE, which is shown in an example of the Pluto package...
View ArticlePivot a dataframe to wide format with values in multiple columns
Hi, I am trying to perform a long to wide transformation of a data frame in Julia. The original data frame I have is: wide = DataFrame(x = 1:12, a = 2:13, b = 3:14, val1 = randn(12), val2 = randn(12),...
View ArticleDoes it make sense for @orderby and @groupby not to commute?
I have a dataframe which I want to group by some column value, and within each group I want the rows sorted by another column. I can do an @orderby |> @groupby, however I feel like a @groupby |>...
View ArticleFastest way to create new column in DataFrames.jl
I found 3 ways to create new columns in DataFrames.jl (two of which are equivalent) df = DataFrame(a = rand(1_000_000), b= rand(1_000_000)) @time transform!(df, [:a, :b] => (a,b)->a + b) @time...
View ArticleParallelism? Async != Parallel?
Hi Guys, for me the Documentation about Parallel Programming is kinda Confusing in Julia. For me its hard to distinguish the first two Groups of Parallel Programming....
View ArticleHow to use NamedDimsArrays(NamedDims.jl) as containers for JuMP Variables?
I am planning to develop a very large power system model. In AMPL it took 1-2h to generate the model and 12h to solve the model with cplex. In JuMP one can use symbols to create DenseAxisArrays of...
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Is there any graph / graph plotting package that allow edges having different...
Usecase: Displaying the architecture of block copolymers. Block copolymers consist of many blocks each of which contains identical monomers and are connected by covalent bond at their joints. I think...
View ArticleHow to apply a function only to the second column of a matrix
How to apply a function only to the second column of a matrix The only way I know of is this. Is there an easier way to apply the sin function to only the second column of a matrix? julia> m = [1....
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Embed webcam in Pluto
It was so cool to see a webcam embedded in a Pluto notebook. But as I tried out the codes shown in the screenshot, I got an error saying camera_input not defined. So what is missing here to achieve...
View ArticleHow to find out which package prevents updating TikzPictures in Julia v1.5
I got the following error message but it doesn’t look helpful. (@v1.5) pkg> add TikzPictures@v3.3.0 Resolving package versions... ERROR: Unsatisfiable requirements detected for package TikzPictures...
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