How to plot Iterations in Julia - function

Question

I coded a function picircle() that estimates pi.
Now I would like to plot this function for N values.
function Plotpi()
p = 100 # precision of π
N = 5
for i in 1:N
picircle(p)
end
end
3.2238805970149254
3.044776119402985
3.1641791044776117
3.1243781094527363
3.084577114427861
Now I am not sure how to plot the function, I tried plot(PP()) but it didn't work
Here I defined picircle:
function picircle(n)
n = n
L = 2n+1
x = range(-1, 1, length=L)
y = rand(L)
center = (0,0)
radius = 1
n_in_circle = 0
for i in 1:L
if norm((x[i], y[i]) .- center) < radius
n_in_circle += 1
end
end
println(4 * n_in_circle / L)
end

Answer 1

Your problem is that your functions don't actually return anything:
julia> x = Plotpi()
3.263681592039801
3.0646766169154227
2.845771144278607
3.18407960199005
3.044776119402985
julia> x
julia> typeof(x)
Nothing
The numbers you see are just printed to the REPL, and print doesn't return any value:
julia> x = print(5)
5
julia> typeof(x)
Nothing
So you probably just want to change your function so that it returns what you want to plot:
julia> function picircle(n)
n = n
L = 2n+1
x = range(-1, 1, length=L)
y = rand(L)
center = (0,0)
radius = 1
n_in_circle = 0
for i in 1:L
if norm((x[i], y[i]) .- center) < radius
n_in_circle += 1
end
end
4 * n_in_circle / L
end
Then:
julia> x = picircle(100)
3.263681592039801
julia> x
3.263681592039801
So now the value of the function is actually returned (rather than just printed to the console). You don't really need a separate function if you just want to do this multiple times and plot the results, a comprehension will do. Here's an example comparing the variability of the estimate with 100 draws vs 50 draws:
julia> using Plots
julia> histogram([picircle(100) for _ ∈ 1:1_000], label = "100 draws", alpha = 0.5)
julia> histogram!([picircle(20) for _ ∈ 1:1_000], label = "20 draws", alpha = 0.5)