This project demonstrates the concept of pixels using a 2D grid of colored squares. It also demonstrates data visualization using a heat map. Students are given a 2D array (or they can create or import one). They use two nested loops (one for x and one for y) to iterate through the array. They then use a set of if-elif-else statements to set the color of each pixel based on the value of that data point.
my_data = [
[62,64,66,68,65,66,67,71,73,74,76,78,81,82,84],
[67,67,65,63,65,64,68,71,75,77,77,81,84,86,85],
[66,64,65,65,63,66,66,71,74,79,82,83,84,83,84],
[64,65,69,64,65,68,71,73,76,78,81,82,82,84,84],
[66,63,65,65,68,71,73,75,77,81,82,82,83,83,84],
[66,66,65,65,66,71,75,78,79,82,81,83,86,84,85],
[65,64,65,68,71,74,77,82,83,83,84,81,83,84,82],
[65,66,65,66,71,73,78,81,82,80,83,84,82,85,81],
[64,64,67,71,76,75,76,79,83,84,82,83,84,83,82],
[66,65,69,71,72,76,78,81,82,83,85,84,83,82,83],
[65,68,71,75,72,76,81,82,83,86,84,85,84,83,81],
[66,71,76,77,75,80,82,83,85,84,84,84,82,83,79],
[71,74,75,78,82,83,83,85,86,85,83,82,83,84,82],
[73,76,78,81,81,84,84,83,84,83,84,85,83,82,83],
[75,77,76,75,82,82,84,81,83,85,84,83,86,82,86],
[78,77,76,81,81,83,83,82,81,80,83,81,83,84,85],
]
# Determine the size of each "pixel"
size = 500./len(my_data)
# Set the initial y-location to the top of the canvas
y = 250-size/2.
# Iterate (loop) through the rows in the list
for row in my_data:
# Set the initial x-location to the left side
# Must be done for each row
x = -250+size/2.
# Iterate (loop) through the data points in each row
for value in row:
# Set the pixel color based on the value of the data
if value <= 65:
color = "blue"
elif value <= 70:
color = "green"
elif value <= 75:
color = "yellow"
elif value <= 80:
color = "orange"
elif value <= 85:
color = "red"
else:
color = "purple"
# Create a square for each "pixel"
pixel = codesters.Square(x, y, size, color, "grey")
# Move right 1 square for the next data point
x += size
# The wait command is optional,
# but it helps students to see the process
stage.wait(.01)
# Move down 1 square for the next row
y -= size
