computer science

Lis (linear algebra library)

Lis (linear algebra library) 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 Lis (linear algebra library) rather than just read about it. In short: Lis (Library of Iterative Solvers for linear systems; pronounced lis]) is a scalable parallel software library to solve discretized linear equations and eigenvalue problems that mainly arise from the numerical solution of partial differential equations using iterative methods. Although it is designed for parallel computers, the library can be used without being conscious of parallel processing.

Key takeaways

Lis (linear algebra library) 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 Lis (linear algebra library) to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Lis (linear algebra library) from memory before moving on to harder problems.

Reference excerpt

Lis (Library of Iterative Solvers for linear systems; pronounced lis]) is a scalable parallel software library to solve discretized linear equations and eigenvalue problems that mainly arise from the numerical solution of partial differential equations using iterative methods. Although it is designed for parallel computers, the library can be used without being conscious of parallel processing.

Features Lis provides facilities for:

Automatic program configuration NUMA aware hybrid implementation with MPI and OpenMP Exchangeable dense and sparse matrix storage formats Basic linear algebra operations for dense and sparse matrices Parallel iterative methods for linear equations and eigenvalue problems Parallel preconditioners for iterative methods Quadruple precision floating point operations Performance analysis Command-line interface to solvers and benchmarks

Example A C program to solve the linear equation A x = b {\displaystyle Ax=b} is written as follows:

System requirements Installing Lis requires a C compiler. If you wish to use the Fortran interface, a Fortran compiler is needed, and the algebraic multigrid preconditioner requires a Fortran 90 compiler. For parallel computing environments, an OpenMP or MPI library is necessary. Lis supports both the Matrix Market and Harwell-Boeing formats for importing and exporting user data.

Packages that use Lis Gerris OpenModelica OpenGeoSys SICOPOLIS STOMP Diablo Kiva Notus Solis GeMA openCFS numgeo freeCappuccino Andromeda Yelmo

Illustrations

Worked examples

Example 1 — a first encounter with Lis (linear algebra library)

Start with the simplest possible case. Write down what Lis (linear algebra library) 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 Lis (linear algebra library) 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 Lis (linear algebra library) 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 Lis (linear algebra library)

In research: Lis (linear algebra library) 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 Lis (linear algebra library) 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: Lis (linear algebra library) is common in secondary-school and first-year university syllabi. It links to neighbouring topics C (programming language) libraries, Fortran libraries, Free simulation software, so understanding it makes those chapters shorter.
In everyday life: Look for Lis (linear algebra library) 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 Lis (linear algebra library) in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Lis (linear algebra library) 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 Lis (linear algebra library) out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Lis (linear algebra library) in simple terms?

Why does Lis (linear algebra library) 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 Lis (linear algebra library)?

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 Lis (linear algebra library).