julia

问题 I am trying to get Julia working in colab. I want to mount gdrive to colab just like in IPython when using IJulia. In ipython I can do it as follows: from google.colab import drive drive.mount('/content/gdrive') I tried following: using PyCall clb = pyimport("google") clb.colab.drive.mount("/content/gdrive") ------------------------------------------------------------------------------------ Warning: Password input may be echoed. Go to this URL in a browser: https://accounts.google.com/o

问题 I would like to inject code into a function. For concreteness, consider a simple simulater: function simulation(A, x) for t in 1:1000 z = randn(3) x = A*x + z end end Sometimes I would like to record the values of x every ten time-steps, sometimes the values of z every 20 time-steps, and sometimes I don't want to record any values. I could, of course, put some flags as arguments to the function, and have some if-else statements. But I would like to rather keep the simulation code clean, and

问题 I would like to inject code into a function. For concreteness, consider a simple simulater: function simulation(A, x) for t in 1:1000 z = randn(3) x = A*x + z end end Sometimes I would like to record the values of x every ten time-steps, sometimes the values of z every 20 time-steps, and sometimes I don't want to record any values. I could, of course, put some flags as arguments to the function, and have some if-else statements. But I would like to rather keep the simulation code clean, and

问题 I have about 50 functions which should consume only even positive numbers. Right now I am checking each time with an "if" whether the number put in is zero or not: function grof(x::Int) if (x % 2) == 0 println("good") else throw("x is not an even number!!!!!!!!!!!!! Stupid programmer!") end end Ideally, I would like to have a datatype which produces this automatically, i.e. function grof(x::EvenInt) println("good") end However, I am not able to produce this datatype by my own since I am

问题 I am trying to generate 12 characters alphanumeric string in julia with the following snippets: a) an = randstring(rand(Bool) ? ('A':'Z') : ('0':'9'), 12) b) an = "" for i in [1:12] an *= randstring(rand(Bool) ? ('A':'Z') : ('0':'9')) end but both gives either complete 12 digits or 12 alphabets but not of their combination. please guide me in generating combination of 12 alphanumeric string. 回答1: If you don't mind using both upper and lower case letters, you can simply call randstring(12) :

问题 I am trying to generate 12 characters alphanumeric string in julia with the following snippets: a) an = randstring(rand(Bool) ? ('A':'Z') : ('0':'9'), 12) b) an = "" for i in [1:12] an *= randstring(rand(Bool) ? ('A':'Z') : ('0':'9')) end but both gives either complete 12 digits or 12 alphabets but not of their combination. please guide me in generating combination of 12 alphanumeric string. 回答1: If you don't mind using both upper and lower case letters, you can simply call randstring(12) :

问题 I am trying to generate 12 characters alphanumeric string in julia with the following snippets: a) an = randstring(rand(Bool) ? ('A':'Z') : ('0':'9'), 12) b) an = "" for i in [1:12] an *= randstring(rand(Bool) ? ('A':'Z') : ('0':'9')) end but both gives either complete 12 digits or 12 alphabets but not of their combination. please guide me in generating combination of 12 alphanumeric string. 回答1: If you don't mind using both upper and lower case letters, you can simply call randstring(12) :

问题 I see occational references to delegation, or the delegation design pattern in Julia. What is this? E.g. I see it mentioned in This file in DataStructures.jl 回答1: This is a form of polymorphism via composition (rather than inheritance) Say one has a wrapper type, wrapping some instance of a concrete subtype of AbstractT where the wrapper itself is intended to be a subtype of AbstractT (Not nesc always true, but in general). To add all the methods one exacts such a subtype of AbstractT to have

问题 I see occational references to delegation, or the delegation design pattern in Julia. What is this? E.g. I see it mentioned in This file in DataStructures.jl 回答1: This is a form of polymorphism via composition (rather than inheritance) Say one has a wrapper type, wrapping some instance of a concrete subtype of AbstractT where the wrapper itself is intended to be a subtype of AbstractT (Not nesc always true, but in general). To add all the methods one exacts such a subtype of AbstractT to have

问题 In python this would be something like: Z = [] z = 1 Z.append([z]) which would create Z= [[1]] for example. But in Julia, I cannot seem to re-create the same structure. I can append, but don't know how to nest. Here is what I am doing in summary: Z = [] # loop z = dotProduct(X, yArray) # single digit append!(Z, z) which then generates the following 0Any[0, 0, 0, 0, 1, 1, 1, 1] where as I would like: [[0], [0], [0], [0], [1], [1], [1], [1]] What is the best way to do this in Julia? 回答1: The