FREE MATLAB Data Import & Visualization Questions and Answers

Question 1

Which MATLAB function is commonly used to import data from a structured text file (e.g., CSV, tab-delimited) into a table variable, preserving column headers and different data types?

Accepted Answer

readtable

Answer

dlmread

Answer

csvread

Answer

textscan

Question 2

You have a large dataset in an Excel file `myData.xlsx` with multiple sheets. You specifically want to import data from a sheet named 'Sheet2' into a MATLAB table. Which of the following commands would accomplish this?

Accepted Answer

data = readtable('myData.xlsx', 'Sheet', 'Sheet2');

Answer

data = xlsread('myData.xlsx', 'Sheet2');

Answer

data = readtable('myData.xlsx', 'Sheet', 2);

Answer

data = importdata('myData.xlsx', 'Sheet2');

Question 3

After importing data into a MATLAB table `T`, you want to visualize the relationship between two numeric columns, 'Temperature' and 'Pressure'. Which plotting function is most appropriate for creating a scatter plot of these two variables?

Accepted Answer

scatter(T.Temperature, T.Pressure);

Answer

bar(T.Temperature, T.Pressure);

Answer

plot(T.Temperature, T.Pressure, 'o');

Answer

histogram(T.Temperature);

Question 4

You have imported sensor data into a timetable `TT` with a datetime row dimension. You want to plot the 'Sensor1' data over time. Which of the following commands would generate a time-series plot?

Accepted Answer

plot(TT.Properties.RowTimes, TT.Sensor1);

Answer

plot(TT.Sensor1);

Answer

plot(TT.Time, TT.Sensor1);

Answer

scatter(TT.Properties.RowTimes, TT.Sensor1);

Question 5

Which of the following statements about importing data from a text file using `readmatrix` is TRUE?

Accepted Answer

`readmatrix` is primarily designed for importing numeric data and will return an error if non-numeric data is encountered in the specified range.

Answer

`readmatrix` can import text data and numeric data into a single matrix, representing text as NaN.

Answer

`readmatrix` automatically detects and skips header rows, importing only the numeric data below.

Answer

`readmatrix` is the recommended function for importing mixed data types into a table.

Question 6

You have a `table` named `dataT` with columns 'City', 'Population', and 'Area'. You want to create a bar chart showing the 'Population' for each 'City'. Which set of commands would achieve this?

Accepted Answer

bar(categorical(dataT.City), dataT.Population);

Answer

bar(dataT.Population, dataT.City);

Answer

bar(dataT.City, dataT.Population);

Answer

plot(dataT.City, dataT.Population, 'bar');