Line Segment in Plots

Specific Domains Visualization
1

Is there a way to create a line segment in plots?

f(x)=2x
plot(f);vline!([f(3), f(4)])

How would I get the lines to go from the y origin to f(x) only?

2

Use the plot command, passing in separately the x and y coordinates of the points on the line(s).

3 
vline!([f(3)],0:f(3))

something like that?

4

No, as I said, use the plot command.

plot([x1, x2], [y1, y2])

5

ok, I see, x sequence, then y sequence)

6 
f(x)=x^2
plot(f,-1:.001:6)
x=5
for i in 1:10
     n(x)=x-(f(x)/ForwardDiff.derivative(f,x))
     Plots.plot!([n(x),n(x)],[0,f(x)])
end

It won’t create verticle lines (which I was able to create with numbers before)

when I run this, it won’t show verticle line, (which I have done with straight numbers

7

What does it display?

8

nothing, no error, and no lines

9

For loops do not return anything. You need to either give the plot a name and look at the value of that variable, or do plot!() at the end.

10

I did use a quotation mark, I think I need a recursive deffinition of x, or n(x), for it to go towards 0

11

I’m trying to do Newton’s method

12

You are not updating x in your loop.,

13 
for i in 1:10
                                       n(x)=x-(f(x)/ForwardDiff.derivative(f,x))
                                       Plots.plot!([n(x),n(x)],[0,f(x)])
                                       x=x-1
       end
14 
 for i in 1:10
             n(x)=x-(f(x)/ForwardDiff.derivative(f,x))
             Plots.plot!([n(x),n(x)],[0,f(n(x))])
             x=n(x)
end
15

And then you need plot!() at the end after the for loop, as I already said?