{ "version": "https://jsonfeed.org/version/1.1", "title": "chem-bla-ics", "description": "Chemblaics (pronounced chem-bla-ics) is the science that uses open science and computers to solve problems in chemistry, biochemistry and related fields.", "home_page_url": "https://chem-bla-ics.linkedchemistry.info/", "feed_url": "https://chem-bla-ics.linkedchemistry.info/2007/11/19/r-based-genetic-algorithm.json", "icon": "https://chem-bla-ics.linkedchemistry.info/assets/images/chem-bla-ics_logo.png", "language": "en", "authors": [ { "name": "Egon Willighagen", "url": "https://orcid.org/0000-0001-7542-0286", "_orcid": "0000-0001-7542-0286" } ], "items": [ { "id": "https://doi.org/10.59350/hfw6p-d6p02", "url": "https://chem-bla-ics.linkedchemistry.info/2007/11/19/r-based-genetic-algorithm.html", "title": "An R-based genetic algorithm", "content_html": "

During my PhD I wrote a simple but effective genetic algorithm package for\nR. Because there was a bug recently found, and there is interest in extending the functionality,\nI have set up a SourceForge project called\ngenalg.

\n\n

The package provides GA support for binary and real-value chromosomes (and integer chromosomes is something that will\nbe added soon), and allows to use custom evaluation functions. Here is some example code:

\n\n
# optimize two values to match pi and sqrt(50)\nevaluate <- function(string=c()) {\n    returnVal = NA;\n    if (length(string) == 2) {\n        returnVal = abs(string[1]-pi) + abs(string[2]-sqrt(50));\n    } else {\n        stop(\"Expecting a chromosome of length 2!\");\n    }\n    returnVal\n}\nmonitor <- function(obj) {\n    # plot the population\n    xlim = c(obj$stringMin[1], obj$stringMax[1]);\n    ylim = c(obj$stringMin[2], obj$stringMax[2]);\n    plot(obj$population, xlim=xlim, ylim=ylim, xlab=\"pi\", ylab=\"sqrt(50)\");\n}\nrbga.results = rbga(c(1, 1), c(5, 10), monitorFunc=monitor,\n    evalFunc=evaluate, verbose=TRUE, mutationChance=0.01)\nplot(rbga.results)\nplot(rbga.results, type=\"hist\")\nplot(rbga.results, type=\"vars\")\n
", "summary": "During my PhD I wrote a simple but effective genetic algorithm package for R. Because there was a bug recently found, and there is interest in extending the functionality, I have set up a SourceForge project called genalg.", "date_published": "2007-11-19T00:00:00+00:00", "date_modified": "2025-02-15T00:00:00+00:00", "tags": ["rstats","chemometrics"], "_citations": [ { "url": "https://doi.org/10.1007/s10489-009-0203-x", "doi": "10.1007/s10489-009-0203-x" , "cito": [ "usesMethodIn" ] } ], "authors": [ { "name": "Egon Willighagen", "url": "https://orcid.org/0000-0001-7542-0286" } ] } ] }