Python Numpy Exercises

Question 1

First, create a random Numpy array of 20 rows and 5 columns and answer the following:

• What is the average value of the second column
• What is the average value of the first 5 rows of the third and fourth columns?
• Create a copy of the array and change each element to '0' in the first 3 rows.
• Change the value of each element in the array to 0.5 if the actual value is >=0.5

Question 2

Following are the average monthly temperature of Baltimore.

• Store the above information (use NumPy arrays)
• Calculate the mean, highest and lowest temperature from the above array.
• What is the average min and max temperatures in the last quarter (Oct-Dec) of the year.
• Use a dot product operation to print the average temperature ((min+max)/2) of each month.

Question 3

Use NumPy random-number generation to create an array of 30 random grades in the range of 60 through 100, then reshape the result into a 10-by-3 array (which will actually represent the Midterm 1, Midterm 2 and Final grade of 10 students)

• Calculate the average of all the grades.
• Calculate the average of the grades in each column and each row.
• Calculate the average of the grade of the first two and last two students.
• Calculate the average of Midterm 1 and Midterm 2 grades of the first 5 students.
• Increase each Midterm 1 and Midterm 2 grade scores by 10% and decrease the Final grade scores by 5% and print the result (Hint: use diagonal matric operation)
• Write functions median and mode that use existing NumPy capabilities to determine the median (middle) and mode (most frequent) of the values in the array.
• Test your function on three arrays of different shapes.