computer science

MEX file

MEX file is a computer science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand MEX file rather than just read about it. In short: A MEX file is a type of computer file that provides an interface between MATLAB or Octave and functions written in C, C++ or Fortran. It stands for "MATLAB executable".

Key takeaways

MEX file belongs to computer science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect MEX file to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of MEX file from memory before moving on to harder problems.

Reference excerpt

A MEX file is a type of computer file that provides an interface between MATLAB or Octave and functions written in C, C++ or Fortran. It stands for "MATLAB executable". When compiled, MEX files are dynamically loaded and allow external functions to be invoked from within MATLAB or Octave as if they were built-in functions. To support the development of MEX files, both MATLAB and Octave offer external interface functions that facilitate the transfer of data between MEX files and the workspace. In addition to MEX files, Octave has its format using its native API, with better performance.

References

External links MEX-files guide from MathWorks MEX-files in the GNU Octave manual

Worked examples

Example 1 — a first encounter with MEX file

Start with the simplest possible case. Write down what MEX file claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In computer science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to MEX file before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about MEX file ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of MEX file

In research: MEX file appears in computer science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses MEX file in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: MEX file is common in secondary-school and first-year university syllabi. It links to neighbouring topics Computing stubs, Cross-platform software, Data analysis software, so understanding it makes those chapters shorter.
In everyday life: Look for MEX file outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study MEX file in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what MEX file means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain MEX file out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is MEX file in simple terms?

A MEX file is a type of computer file that provides an interface between MATLAB or Octave and functions written in C, C++ or Fortran. It stands for "MATLAB executable".

Why does MEX file matter?

Because it connects several computer science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study MEX file?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on MEX file.