Multithreading 使用Julia绘制带有多线程的mandelbrot,竞争条件问题
我是Julia的新手,我正在尝试实现Julia的多线程,但我相信我遇到了“竞争条件问题”。这里我正在绘制mandelbrot图,但我相信由于竞争条件,数组索引[n]会干扰颜色映射。我尝试将原子特性用于索引n,但显然我不能将该类型用作索引。下面是要比较的图片以及代码块 谢谢Multithreading 使用Julia绘制带有多线程的mandelbrot,竞争条件问题,multithreading,julia,atomic,mandelbrot,Multithreading,Julia,Atomic,Mandelbrot,我是Julia的新手,我正在尝试实现Julia的多线程,但我相信我遇到了“竞争条件问题”。这里我正在绘制mandelbrot图,但我相信由于竞争条件,数组索引[n]会干扰颜色映射。我尝试将原子特性用于索引n,但显然我不能将该类型用作索引。下面是要比较的图片以及代码块 谢谢 module MandelBrot using Plots #make some functions for mandelbrot stuff #find out if a number is part of the set
module MandelBrot
using Plots
#make some functions for mandelbrot stuff
#find out if a number is part of the set
#remember the mandelbrot is symmetrical about the real number plane
function mandel(c)
#determine if a number is in the set or not in the set -
max_iter = 1000;
bound = 2
z = 0
n = 0
#if the magnitude of z exceeds two we know we are done.
while abs(z)<bound && n<max_iter
z = z^2+c
n+=1
end
return n #if n is 1000 assume c is good, else not of the set
end
#map n to a color
function brot(n)
rgb = 250
m = (n%rgb) /rgb#divide 250
if 0< n <= 250
c = RGB(1,m,0)
elseif 250<n<=500
c = RGB(1-m,1,0)
elseif 500<n<=750
c = RGB(0,1,m)
elseif 750<n<=999
c = RGB(0,1-m,1)
else
c=RGB(0,0,0)
end
return c
#TODO: append this c to an array of color values
end
#mrandom
function mandelbrot(reals,imags)
#generate #real amount of points between -2 and 1
#and #imag amount of points between 0 and i
#determine if any of those combinations are in the mandelbrot set
r = LinRange(-2,1,reals)
i = LinRange(-1,1,imags)
master_list = zeros(Complex{Float64},reals*imags,1)
color_assign = Array{RGB{Float64}}(undef,reals*imags,1)
#n = Threads.Atomic{Int64}(1)
n = 1
Threads.@threads for real_num in r
for imaginary_num in i
#z = complex(real_num, imaginary_num) #create the number
#master_list[n] = z #add it to the list
#color_assign[n,1] = (brot ∘ mandel)(z) #function of function! \circ + tab
#or would this be faster? since we dont change z all the time?
master_list[n] = complex(real_num, imaginary_num)
color_assign[n,1] = (brot ∘ mandel)(complex(real_num, imaginary_num))
n+=1
#Threads.atomic_add!(n,1)
end
end
gr(markerstrokewidth=0,markerstrokealpha=0,markersize=.5,legend=false)
scatter(master_list,markerstrokecolor=color_assign,color=color_assign,aspect_ratio=:equal)
end
#end statement for the module
end
julia> @time m.mandelbrot(1000,1000)
2.260481 seconds (6.01 M allocations: 477.081 MiB, 9.56% gc time)
模块MandelBrot
使用绘图
#为mandelbrot的东西做一些函数
#找出一个数字是否是集合的一部分
#记住mandelbrot关于实数平面是对称的
曼德尔函数(c)
#确定某个数字是否在集合中-
最大电阻=1000;
界限=2
z=0
n=0
#如果z的大小超过2,我们就知道我们完成了。
当abs(z)时,以下是应该有帮助的:
function mandelbrot(reals,imags)
r = LinRange(-2,1,reals)
i = LinRange(0,1,imags)
master_list = zeros(Complex{Float64},reals*imags,1)
color_assign = Array{RGB{Float64}}(undef,reals*imags,1)
Threads.@threads for a in 1:reals
real_num = r[a]
for (b, imaginary_num) in enumerate(i)
n = (a-1)*imags + b
master_list[n] = complex(real_num, imaginary_num)
color_assign[n, 1] = (brot ∘ mandel)(complex(real_num, imaginary_num))
end
end
gr(markerstrokewidth=0,markerstrokealpha=0,markersize=1,legend=false)
scatter(master_list,markerstrokecolor=color_assign,color=color_assign,aspect_ratio=:equal)
end
该方法是将n
计算为r
和i
沿线指数的函数。
还要注意,我使用1:reals
而不仅仅是枚举(r)
作为线程。@Threads
不接受任意迭代器
请注意,您的代码可能会在其他版本中进行清理,但如果没有完全可复制的示例,则很难做到这一点。谢谢您,卡明斯基先生!我将很快尝试一下-我添加了完整的代码以保证可复制性,很抱歉之前没有这么做。我刚刚检查过它-所有这些都可以在多个线程上运行。只需将其命名为MandelBrot.MandelBrot(10001000)
。