Element-wise arithmetic in NumPy - Mini Project: Build & Apply

Element-wise arithmetic with NumPy arrays

📖 Scenario: Imagine you have two lists of daily temperatures from two different cities. You want to compare them by doing element-wise arithmetic operations like addition, subtraction, multiplication, and division.

🎯 Goal: You will create two NumPy arrays with exact temperature values, set a scaling factor, perform element-wise arithmetic operations between the arrays and the scaling factor, and finally print the results.

📋 What You'll Learn

Use NumPy arrays for the temperature data

Create a scaling factor variable

Perform element-wise addition, subtraction, multiplication, and division

Print the resulting arrays

💡 Why This Matters

🌍 Real World

Element-wise arithmetic is useful when comparing or combining data from different sources, like temperatures from multiple cities or sales data from different stores.

💼 Career

Data scientists often use element-wise operations to preprocess data, create new features, or analyze relationships between datasets efficiently.

1

Create two NumPy arrays with temperature data

Import NumPy as np. Create a NumPy array called city1_temps with these exact values: [20, 22, 19, 24, 21]. Create another NumPy array called city2_temps with these exact values: [18, 21, 20, 23, 22].

NumPy

import numpy as np
# Create city1_temps array with [20, 22, 19, 24, 21]
# Create city2_temps array with [18, 21, 20, 23, 22]

Need a hint?

Use np.array([...]) to create NumPy arrays with the exact values given.

2

Set a scaling factor

Create a variable called scale and set it to the exact value 2.

NumPy

import numpy as np
city1_temps = np.array([20, 22, 19, 24, 21])
city2_temps = np.array([18, 21, 20, 23, 22])
# Create scale variable and set it to 2

Need a hint?

Just assign the number 2 to a variable named scale.

3

Perform element-wise arithmetic operations

Create four new variables: added, subtracted, multiplied, and divided. Set added to the element-wise sum of city1_temps and city2_temps. Set subtracted to the element-wise difference of city1_temps minus city2_temps. Set multiplied to the element-wise product of city1_temps and scale. Set divided to the element-wise division of city2_temps by scale.

NumPy

import numpy as np
city1_temps = np.array([20, 22, 19, 24, 21])
city2_temps = np.array([18, 21, 20, 23, 22])
scale = 2
# Create added, subtracted, multiplied, divided with element-wise operations

Need a hint?

Use +, -, *, and / operators between arrays and variables for element-wise operations.

4

Print the results

Print the variables added, subtracted, multiplied, and divided each on a separate line.

NumPy

import numpy as np
city1_temps = np.array([20, 22, 19, 24, 21])
city2_temps = np.array([18, 21, 20, 23, 22])
scale = 2
added = city1_temps + city2_temps
subtracted = city1_temps - city2_temps
multiplied = city1_temps * scale
divided = city2_temps / scale
# Print added, subtracted, multiplied, divided each on its own line

Need a hint?

Use four print() statements, one for each variable.