FREE MATLAB Data Import and Visualization Questions and Answers

Question 1

A data analyst has a CSV file named 'sensor_data.csv' with mixed data types (numbers and text) and a header row.
Which function is most suitable for importing this data into MATLAB as a table, preserving the data types and using the header for variable names?

Accepted Answer

readtable('sensor_data.csv')

Answer

readmatrix('sensor_data.csv')

Answer

load('sensor_data.csv')

Answer

readcell('sensor_data.csv')

Question 2

A user has imported data into a table named `patientData`. The table has variables named 'LastName', 'Age', and 'BloodPressure'. How can the user extract all values from the 'Age' column into a standard numeric vector?

Accepted Answer

patientData.Age

Answer

patientData('Age')

Answer

patientData{'Age'}

Answer

patientData['Age']

Question 3

Which of the following commands will create a plot of `y` versus `x` with a red, dashed line and circular markers?

Accepted Answer

plot(x, y, 'r--o')

Answer

plot(x, y, 'red-.*')

Answer

plot(x, y, 'LineStyle', 'red', 'Marker', 'dashed')

Answer

plot(x, y, 'Color', 'r', 'Line', '--', 'Marker', 'o')

Question 4

A researcher needs to save a figure currently displayed on the screen to a high-resolution PNG file named 'figure1.png' for publication. Which command is most appropriate for this task?

Accepted Answer

exportgraphics(gcf, 'figure1.png', 'Resolution', 300)

Answer

save('figure1.png')

Answer

print(gcf, 'figure1.png', '-dpng', '-r300')

Answer

savefig('figure1.png')

Question 5

A user wants to create a stacked bar chart from a numeric matrix `data`, where each column of `data` represents a category and each row represents a series. Which command correctly generates a stacked bar chart?

Accepted Answer

bar(data, 'stacked')

Answer

plot(data, 'Type', 'stackedbar')

Answer

stackedbar(data)

Answer

bar(data, 'Style', 'stack')

Question 6

An engineer has an Excel file, 'test_results.xlsx', with data on multiple worksheets named 'Trial1', 'Trial2', and 'Trial3'. What is the first step required to programmatically import the data from 'Trial2' into a table?

Accepted Answer

Use `readtable('test_results.xlsx', 'Sheet', 'Trial2')`.

Answer

Use `xlsread('test_results.xlsx', 'Trial2')` as it's the only way.

Answer

Open the file in Excel and save 'Trial2' as a separate CSV file.

Answer

First, use `sheetnames('test_results.xlsx')` to get all sheet names, then loop through them.

A data analyst has a CSV file named 'sensor_data.csv' with mixed data types (numbers and text) and a header row.Which function is most suitable for importing this data into MATLAB as a table, preserving the data types and using the header for variable names?

A data analyst has a CSV file named 'sensor_data.csv' with mixed data types (numbers and text) and a header row.
Which function is most suitable for importing this data into MATLAB as a table, preserving the data types and using the header for variable names?