Draw log base 2 graph using Python turtle graphics

Question

I tried this:

if wave_type == "log":
  emily.up ()
  emily.goto(0,1)
  emily.down ()
  for x in range(100):
    y = math.log( x ) / math.log( 2 )
    elaine.goto(x, y)

but it didn't work. Please help

Answer 1

Here's a rough start -- since range() can't handle float, we use 10x the range and then divide by 10 when we use the value. (Look into arange() in numpy as a way around this.) I'm also graphing a smaller area, and using setworldcoordinates() to enforce that, so we can see the interesting part of the graph where it crosses the X-axis:

import math
from turtle import Turtle, Screen

screen = Screen()
screen.setworldcoordinates(0, -5, 10, 5)

emily = Turtle(visible=False)
emily.forward(10)
emily.penup()

for x in range(1, 100):
    y = math.log(x / 10) / math.log(2)
    emily.goto(x / 10, y)
    emily.pendown()

screen.exitonclick()

You can fill in the Y-axis, add tick marks, label axes, increase resolution, etc. as you see fit:

Answer 2

Log(0) is undefined. Hence your code will error on the first iteration of the for loop (x will be 0).

Perhaps you want range(1, 100)? Or even better have more x values around 1 as this is where the graph is changing the most for a smoother plot.