Problem 42848. Lambert's W

Created by Daniel Pereira

Solve Later

{"relationships":[{"relationshipType":"http://schemas.mathworks.com/matlab/code/2013/relationships/document","targetMode":"","relationshipId":"rId1","target":"/matlab/document.xml"},{"relationshipType":"http://schemas.mathworks.com/matlab/code/2013/relationships/output","targetMode":"","relationshipId":"rId2","target":"/matlab/output.xml"}],"parts":[{"partUri":"/matlab/document.xml","relationship":[],"contentType":"application/vnd.mathworks.matlab.code.document+xml","content":"<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n<w:document xmlns:w=\"http://schemas.openxmlformats.org/wordprocessingml/2006/main\"><w:body><w:p><w:pPr><w:pStyle w:val=\"text\"/></w:pPr><w:r><w:t>Matlab cody does not support lambertw. Try to create a lambert's w function yourself.</w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"text\"/></w:pPr><w:r><w:t>Lambert's W is the function that solves</w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"code\"/></w:pPr><w:r><w:t><![CDATA[x*exp(x) = A;]]></w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"text\"/></w:pPr><w:r><w:t>given the value of A.</w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"text\"/></w:pPr><w:r><w:t>Read more about Lambert's W</w:t></w:r><w:r><w:t> </w:t></w:r><w:hyperlink w:docLocation=\"https://en.wikipedia.org/wiki/Lambert_W_function\"><w:r><w:t>here</w:t></w:r></w:hyperlink><w:r><w:t>.</w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"text\"/></w:pPr><w:r><w:t>Though it is not particularly appropriate for this particular function, consider using</w:t></w:r><w:r><w:t> </w:t></w:r><w:hyperlink w:docLocation=\"https://en.wikipedia.org/wiki/Newton's_method\"><w:r><w:t>Newton-Raphson's method</w:t></w:r></w:hyperlink><w:r><w:t>. Since all test cases will converge if starting with 0.</w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"text\"/></w:pPr><w:r><w:t>The relative tolerance for the result of x*exp(x) compared to A is 1e-5.</w:t></w:r></w:p></w:body></w:document>"},{"partUri":"/matlab/output.xml","contentType":"text/xml","content":"<?xml version=\"1.0\" encoding=\"UTF-8\" standalone=\"no\" ?><embeddedOutputs><metaData><evaluationState>manual</evaluationState><layoutState>code</layoutState><outputStatus>ready</outputStatus></metaData><outputArray type=\"array\"/><regionArray type=\"array\"/></embeddedOutputs>"}]}

Solve

Solution Stats

139 Solutions
40 Solvers

Last Solution submitted on Nov 20, 2021

Last 200 Solutions

Problem Comments

1 Comment

1 Comment

Peng Liu on 5 May 2016

See Cleve Moler's implementation at http://blogs.mathworks.com/cleve/2013/09/02/the-lambert-w-function/

Problem Recent Solvers40

Problem Tags

convergece exponential lambert lambertw newton numeric solution solve tolerance w

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Problem 42848. Lambert's W

Solution Stats

Last 200 Solutions

Problem Comments

Problem Recent Solvers40

Suggested Problems

More from this Author9

Problem Tags

Community Treasure Hunt

Problem 42848. Lambert's W

Solution Stats

Last 200 Solutions

Problem Comments

Problem Recent Solvers40

Suggested Problems

More from this Author9

Problem Tags

Community Treasure Hunt

Players