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Introduction to the Live Editor in MATLAB Mobile

Open Live Script

This example shows how to interact with live scripts that combine input code and output.

Add formatted text to enhance your narrative, and share the live script with others as an interactive document using MATLAB Drive™.

When working with live scripts in MATLAB Mobile on an iPad or Android Tablet, you can use the available toolstrip to create new live scripts, format text, and run code. Advanced insertions including inserting interactive controls and tasks are not supported. If an existing live script contains interactive controls, you can use the existing controls.

On an iPhone or Android phone, you can open and edit existing live scripts in MATLAB Mobile and run them using the available Run button. The toolstrip is not available and text formatting is not supported.

Open a Live Script

You can open and edit an existing live script in MATLAB Mobile. To open a live script, go to the Files view or use the edit command. In MATLAB Mobile on an iPad or Android Tablet, you also can create a live script. To create a live script, on the Live Editor toolstrip, tap . You also can create a live script from the Files view by tapping and selecting New Live Script.

Add the Census Data

Divide your live script into sections. Sections can contain text, code, and output. MATLAB code appears with a gray background and output appears with a white background.

To create a new section, on the Live Editor toolstrip, tap the section break button. You also can type two percent signs (%%) in the live script and then press Enter.

Add the US Census data for 1900 to 2000.

years = (1900:10:2000);                                  % Time interval
pop = [75.995 91.972 105.711 123.203 131.669 ...         % Population Data
   150.697 179.323 213.212 228.505 250.633 265.422]
pop = 1×11

   75.9950   91.9720  105.7110  123.2030  131.6690  150.6970  179.3230  213.2120  228.5050  250.6330  265.4220

Visualize the Population Change Over Time

Sections can be run independently. To run the code in a section, on the Live Editor toolstrip, tap the Run Section button. You also can tap the blue bar that appears when you tap the left side of a section. When you run a section, output and figures appear together inline with the code that produced them.

Plot the population data against the year.

plot(years,pop,'bo');                                    % Plot the population data
axis([1900 2020 0 400]);
title('Population of the U.S. 1900-2000');
ylabel('Millions');
xlabel('Year')
ylim([50 300])

Can we predict the US population in the year 2010?

Fitting the Data

Add supporting information to the text. Use the options in the Live Editor toolstrip to format text.

Let's try fitting the data with polynomials.

x = (years-1900)/50;
coef1 = polyfit(x,pop,1) 
coef1 = 1×2

   98.9924   66.1296


coef2 = polyfit(x,pop,2)
coef2 = 1×3

   15.1014   68.7896   75.1904


coef3 = polyfit(x,pop,3)
coef3 = 1×4

  -17.1908   66.6739   29.4569   80.1414

Plotting the Curves

Create sections with any number of text and code lines.

We can plot the linear, quadratic, and cubic curves fitted to the data. We'll use the polyval function to evaluate the fitted polynomials at the points in x.

pred1 = polyval(coef1,x);
pred2 = polyval(coef2,x);
pred3 = polyval(coef3,x);
[pred1; pred2; pred3]
ans = 3×11

   66.1296   85.9281  105.7266  125.5250  145.3235  165.1220  184.9205  204.7190  224.5174  244.3159  264.1144
   75.1904   89.5524  105.1225  121.9007  139.8870  159.0814  179.4840  201.0946  223.9134  247.9403  273.1753
   80.1414   88.5622  101.4918  118.1050  137.5766  159.0814  181.7944  204.8904  227.5441  248.9305  268.2243

Now let's plot the predicted values for each polynomial.

hold on
plot(years,pred1)
plot(years,pred2)
plot(years,pred3)
ylim([50 300])
legend({'Data' 'Linear' 'Quadratic' 'Cubic'},'Location', 'NorthWest')
hold off

Predicting the Population

You can share your live script with other MATLAB users so that they can reproduce your results using MATLAB Drive. If you open a live script that contains sliders, drop-downs, check boxes, edit fields, or buttons, you can use the controls to change the value of variables interactively. Inserting new controls is not supported on MATLAB Mobile.

We can now calculate the predicted population of a given year by adjusting the year via the slider below:

year = 2027;
xyear = (year-1900)/50;
pred1 = polyval(coef1,xyear);
pred2 = polyval(coef2,xyear);
pred3 = polyval(coef3,xyear);
[pred1 pred2 pred3]
ans = 1×3

  317.5703  347.3443  303.4082

For the year 2010 for example, the linear and cubic fits predict similar values of about 284 million people, while the quadratic fit predicts a much higher value of about 300 million people.