Julia Plotting: delete and modify existing lines

Question

Two questions in one: Given a line plotted in Julia, how can I

1. delete it from the plot and legend (without clearing the whole plot)
2. change its propert

Answer 1

I have to say that I don't know what the formal way is to accomplish them.

There is a cheating method.

plt.series_list stores all the plots (line, scatter...).
If you have 200 lines in the plot, then length(plt.series_list) will be 200.

plt.series_list[1].plotattributes returns a dictionary containing attributes for the first line(or scatter plot, depends on the order).

One of the attributes is :linealpha, and we can use it to modify the transparency of a line or let it disappear.

# your code ...

plot!(0:.1:1, x->coefs[2]*x+coefs[1], c=:blue)  # plot new regression line

# modify the alpha value of the previous line
if i > 1
    plt.series_list[end-1][:linealpha] = 0.1
end

# make the previous line invisible
if i > 2
    plt.series_list[end-2][:linealpha] = 0.0
end

frame(anim)
# your code ...