mathematics

Wilkinson matrix

Wilkinson matrix is a mathematics 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 Wilkinson matrix rather than just read about it. In short: In linear algebra, Wilkinson matrices are symmetric, tridiagonal, order-N matrices with pairs of nearly, but not exactly, equal eigenvalues. It is named after the British mathematician James H.

Key takeaways

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

Reference excerpt

In linear algebra, Wilkinson matrices are symmetric, tridiagonal, order-N matrices with pairs of nearly, but not exactly, equal eigenvalues. It is named after the British mathematician James H. Wilkinson. For N = 7, the Wilkinson matrix is given by

[ 3 1 0 0 0 0 0 1 2 1 0 0 0 0 0 1 1 1 0 0 0 0 0 1 0 1 0 0 0 0 0 1 1 1 0 0 0 0 0 1 2 1 0 0 0 0 0 1 3 ] . {\displaystyle {\begin{bmatrix}3&1&0&0&0&0&0\\1&2&1&0&0&0&0\\0&1&1&1&0&0&0\\0&0&1&0&1&0&0\\0&0&0&1&1&1&0\\0&0&0&0&1&2&1\\0&0&0&0&0&1&3\\\end{bmatrix}}.}

Wilkinson matrices have applications in many fields, including scientific computing, numerical linear algebra, and signal processing.

References

Worked examples

Example 1 — a first encounter with Wilkinson matrix

Start with the simplest possible case. Write down what Wilkinson matrix claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In mathematics, 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 Wilkinson matrix 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 Wilkinson matrix 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 Wilkinson matrix

In research: Wilkinson matrix appears in mathematics 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 Wilkinson matrix 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: Wilkinson matrix is common in secondary-school and first-year university syllabi. It links to neighbouring topics Matrices (mathematics), Matrix stubs, Numerical linear algebra, so understanding it makes those chapters shorter.
In everyday life: Look for Wilkinson matrix 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 Wilkinson matrix in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Wilkinson matrix 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 Wilkinson matrix out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Wilkinson matrix in simple terms?

In linear algebra, Wilkinson matrices are symmetric, tridiagonal, order-N matrices with pairs of nearly, but not exactly, equal eigenvalues. It is named after the British mathematician James H.

Why does Wilkinson matrix matter?

Because it connects several mathematics 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 Wilkinson matrix?

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 Wilkinson matrix.