MATLAB Programming Fundamentals - MathWorks

Write Script-Based Test Using Local Functions

This example shows how to write a script-based test that uses local functions as helper

functions. The example function approximates the sine and cosine of an angle. The script-

based test checks the approximation using local functions to check for equality within a

tolerance.

Create approxSinCos Function to Test

Create this function in a file, approxSinCos.m, in your current MATLAB folder. This

function takes an angle in radians and approximates the sine and cosine of the angle

using Taylor series.

function [sinA,cosA] = approxSinCos(x)

% For a given angle in radians, approximate the sine and cosine of the angle

% using Taylor series.

sinA = x;

cosA = 1;

altSign = -1;

for n = 3:2:26

sinA = sinA + altSign*(x^n)/factorial(n);

cosA = cosA + altSign*(x^(n-1))/factorial(n-1);

altSign = -altSign;

end

Create Test Script

In your current MATLAB folder, create a new script, approxSinCosTest.m.

Note: Including functions in scripts requires MATLAB® R2016b or later.

%% Test 0rad

% Test expected values of 0

[sinApprox,cosApprox] = approxSinCos(0);

assertWithAbsTol(sinApprox,0)

assertWithRelTol(cosApprox,1)

%% Test 2pi

% Test expected values of 2pi

[sinApprox,cosApprox] = approxSinCos(2*pi);

assertWithAbsTol(sinApprox,0)

Write Script-Based Test Using Local Functions