Solution

.gitignore

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+__pycache__/*

constants.py

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+PLOT_HEIGHT = 400
+PLOT_WIDTH = 400
+TICK_LENGTH = 5

generate_data.py

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+from random import randint, gauss
+
+def generate_data(n, xmin, xmax, slope, intercept, error):
+    sample = []
+    for i in range(n):
+        x = randint(xmin, xmax)
+        y = round(gauss(intercept + x * slope, error))
+        sample.append([x, y])
+    return sample

helpers.py

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+from turtle import *
+
+def flyto(x, y):
+    penup()
+    goto(x, y)
+    pendown()

pyproject.toml

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+[tool.poetry]
+name = "lab-scatter"
+version = "0.1.0"
+description = ""
+authors = ["Chris Proctor <chris@chrisproctor.net>"]
+readme = "README.md"
+
+[tool.poetry.dependencies]
+python = "^3.10"
+superturtle = "^0.1.0"
+
+
+[build-system]
+requires = ["poetry-core"]
+build-backend = "poetry.core.masonry.api"

scatterplot.py

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+# What needs to be taught?
+# - return values
+#   - unpacking multiple return values 
+# - list comprehensions
+# - named function arguments
+#   - after positional
+#   - like dictionaries
+#   - 
+# - modules
+
+# Parameters: 
+# - the actual drawing will be 
+
+from turtle import *
+from math import floor, ceil, log
+import constants
+from helpers import flyto
+from superturtle.movement import no_delay
+from generate_data import generate_data
+
+def draw_scatterplot(data, size=5, color="black"):
+    "Draws a scatter plot, showing the data"
+    prepare_screen()
+    draw_axes(data)
+    draw_points(data, color, size)
+
+def prepare_screen():
+    """Sets up the 
+    """
+    screensize(400, 400)
+    setworldcoordinates(-20, -20, 420, 420)
+
+def draw_axes(data):
+    """Draws the scatter plot's axes.
+    """
+    flyto(0, 0)
+    goto(0, constants.PLOT_HEIGHT)
+    flyto(0, 0)
+    goto(constants.PLOT_WIDTH, 0)
+
+    y_values = get_y_values(data)
+    ymin, ymax = get_bounds(y_values)
+    draw_y_tick(0, ymin)
+    draw_y_tick(constants.PLOT_HEIGHT, ymax)
+    for tick in get_tick_range(y_values):
+        position = scale(tick, ymin, ymax, 0, constants.PLOT_HEIGHT)
+        draw_y_tick(position, tick)
+
+    x_values = get_x_values(data)
+    xmin, xmax = get_bounds(x_values)
+    draw_x_tick(0, xmin)
+    draw_x_tick(constants.PLOT_WIDTH, xmax)
+    for tick in get_tick_range(x_values):
+        position = scale(tick, xmin, xmax, 0, constants.PLOT_WIDTH)
+        draw_x_tick(position, tick)
+
+def get_tick_range(values):
+    "Returns a range of positions for ticks"
+    vmin, vmax = get_bounds(values)
+    tick_interval = get_tick_interval(values)
+    first_tick = ceil(vmin / tick_interval) * tick_interval
+    print(tick_interval)
+    print(first_tick)
+    print(vmax)
+    return range(first_tick, vmax, tick_interval)
+
+def get_tick_interval(values):
+    ""
+    vmin, vmax = get_bounds(values)
+    log_span = log(vmax - vmin, 10)
+    return 10 ** floor(log_span)
+
+def draw_points(data, color, size):
+    xmin, xmax = get_bounds(get_x_values(data))
+    ymin, ymax = get_bounds(get_y_values(data))
+    for x, y in data:
+        sx = scale(x, xmin, xmax, 0, constants.PLOT_WIDTH)
+        sy = scale(y, ymin, ymax, 0, constants.PLOT_HEIGHT)
+        draw_point(sx, sy, color, size)
+
+def draw_point(x, y, color, size):
+    flyto(x, y)
+    dot(size, color)
+
+def get_bounds(data):
+    return min(data), max(data)
+
+def get_x_values(data):
+    return [x for x, y, in data]
+
+def get_y_values(data):
+    return [y for x, y in data]
+
+def draw_y_tick(position, label):
+    flyto(0, position)
+    goto(-constants.TICK_LENGTH, position)
+    write(label, align='right')
+
+def draw_x_tick(position, label):
+    flyto(position, 0)
+    goto(position, -constants.TICK_LENGTH)
+    flyto(position, -constants.TICK_LENGTH - 10)
+    write(label, align='center')
+
+def scale(value, domain_min, domain_max, range_min, range_max):
+    ratio = (value - domain_min) / (domain_max - domain_min)
+    return range_min + ratio * (range_max - range_min)
+
+with no_delay():
+    data = generate_data(50, 10, 500, 25, 100, 1000)
+    draw_scatterplot(data, size=5, color="blue")
+    hideturtle()
+input()