Step-by-Step Graphs in Octave

In this lesson, I will explain how to create a step-by-step graph in Octave.

What is a step-by-step graph? The graph of a function is drawn in a discrete form with jumps that look like steps, and it is not continuous. The step graph is useful for highlighting variations in the function's increment.

Let me give you a practical example.

Create an array, x, of the independent variable with values 1 to 20.

>> x=linspace(1,20,20);

Now, create an array for a linear function.

>> y=x

Plot the function with the plot(x,y) function.

>> plot(x,y)

The graph of the function y = f(x) = x is a simple line passing through the origin.

To create a step-by-step graph, use the stairs(x, y) function.

>> stairs(x,y)

The diagram shows the same graph using steps.

The steps are all the same, which means the function has a constant growth rate.

Let me give you another practical example

Create a function y = x^2.

y=x.^2

Plot the function using the instruction plot(x,y)

In this case, the function grows exponentially.

Use the command stairs(x, y) to draw the step-by-step diagram of the function.

>> stairs(x,y)

The step-by-step diagram shows steps of different heights.

The last steps are higher, which means the function has a growth rate that tends to increase.

How to display multiple graphs in one diagram?

To display two step-by-step graphs in the same diagram, indicate the two functions in a Y matrix with two columns.

>> X = linspace(0,4*pi,50)';
>> Y = [0.5*cos(X), 2*cos(X)];

The first column of the Y matrix indicates the values of the function 1/2*cos(X), and the second column indicates the values of the function 2*cos(x).

Now, display the graph using the command stairs(Y) or stairs(X, Y).

>> stairs(X,Y)

In this way, the step-by-step graphs of both functions are displayed in the diagram.

If you find this Niagara lesson useful, keep following us.