{"id":13544,"date":"2026-02-10T11:04:08","date_gmt":"2026-02-10T16:04:08","guid":{"rendered":"https:\/\/blogs.mathworks.com\/cleve\/?p=13544"},"modified":"2026-02-17T19:15:35","modified_gmt":"2026-02-18T00:15:35","slug":"beresford-parlett","status":"publish","type":"post","link":"https:\/\/blogs.mathworks.com\/cleve\/2026\/02\/10\/beresford-parlett\/","title":{"rendered":"Beresford Parlett"},"content":{"rendered":"<div class=\"content\"><!--introduction-->\r\n<p>\r\n<img decoding=\"async\" vspace=\"5\" hspace=\"5\" src=\"https:\/\/blogs.mathworks.com\/cleve\/files\/Beresford_Linocut.jpg\" alt=\"\"> <\/p>\r\n<p>\r\n<a href=\"https:\/\/www.henkvandervorst.nl\/computing.html\" target=\"_blank\" rel=\"noopener\">Linocuts<\/a> by Henk van der Vorst.<\/p>\r\n<p>Beresford Parlett passed away last Saturday, February 7. He was 93 years old. I have known him since graduate school at Stanford.<\/p>\r\n<!--\/introduction-->\r\n<h3>Contents<\/h3>\r\n<div>\r\n<ul>\r\n<li>\r\n<a href=\"#3c3dcb0c-4455-49f1-ac38-98a43529f308\">Stanford<\/a>\r\n<\/li>\r\n<li>\r\n<a href=\"#89df87e4-fd84-4eab-a23f-1e6d7f14b917\">Career<\/a>\r\n<\/li>\r\n<li>\r\n<a href=\"#e8b82c26-30d6-481e-961e-5208e837cc5f\">Holy Grail<\/a>\r\n<\/li>\r\n<\/ul>\r\n<\/div>\r\n<h4>Stanford<a name=\"3c3dcb0c-4455-49f1-ac38-98a43529f308\"><\/a>\r\n<\/h4>\r\n<p>\r\n<img decoding=\"async\" vspace=\"5\" hspace=\"5\" src=\"https:\/\/blogs.mathworks.com\/cleve\/files\/photoNormal.jpg\" alt=\"\"> <\/p>\r\n<p>Source: George M. Bergman, Berkeley.<\/p>\r\n<p>\r\n<a href=\"https:\/\/en.wikipedia.org\/wiki\/Beresford_Parlett\" target=\"_blank\" rel=\"noopener\">Beresford<\/a> was born in 1932 in London. He received his bachelor's degree in mathematics from Oxford in 1955.<\/p>\r\n<p>Beresford came to graduate school at Stanford in 1958. He had very little money and no place to live. At first, he slept in the math faculty women's lounge and showered in the gymnasium. Fortunately, after two quarters, the math made him a teaching assistant, and he was able to move out of the lounge.<\/p>\r\n<p>I came to Stanford in 1961, three years after Beresford. We were both students of <a href=\"https:\/\/blogs.mathworks.com\/cleve\/2013\/01\/07\/george-forsythe\/\">George Forsythe<\/a>, and are both on the <a href=\"http:\/\/infolab.stanford.edu\/pub\/voy\/museum\/forsythetree.html\" target=\"_blank\" rel=\"noopener\">Forsythe tree<\/a>.<\/p>\r\n<h4>Career<a name=\"89df87e4-fd84-4eab-a23f-1e6d7f14b917\"><\/a>\r\n<\/h4>\r\n<p>\r\n<img decoding=\"async\" vspace=\"5\" hspace=\"5\" src=\"https:\/\/blogs.mathworks.com\/cleve\/files\/parlett.jpg\" alt=\"\"> <\/p>\r\n<p>Source: EECS, Berkeley.<\/p>\r\n<p>Beresford received his Ph.D. in math from Stanford in 1962.<\/p>\r\n<p>He was a postdoc for two years at NYU's Courant Institute and for one year at the Stevens Institute of Technology<\/p>\r\n<p>Beresford joined the U. C Berkeley math faculty in 1965 and remained there until his retirement.<\/p>\r\n<h4>Holy Grail<a name=\"e8b82c26-30d6-481e-961e-5208e837cc5f\"><\/a>\r\n<\/h4>\r\n<p>Many researchers, including Parlett, contributed to the search for the <a href=\"https:\/\/en.wikipedia.org\/wiki\/Holy_Grail\" target=\"_blank\" rel=\"noopener\">Holy Grail<\/a> of matrix eigenvalue computation, an algorithm with O(n) time complexity. The quest culminated in the MRRR algorithm, the subject of the <a href=\"https:\/\/www.cs.utexas.edu\/~inderjit\/Talks\/holygrail.pdf\" target=\"_blank\" rel=\"noopener\">Ph.D. thesis<\/a> of one of Beresford's students, Inderjit Dhillon.<\/p>\r\n<p>Beresford's specialities include<\/p>\r\n<div>\r\n<ul>\r\n<li>Matrix eigenvalues<\/li>\r\n<li>QR algorithm<\/li>\r\n<li>Lanczos algorithm<\/li>\r\n<li>MRRR algorithm<\/li>\r\n<li>Sparse matrices<\/li>\r\n<\/ul>\r\n<\/div>\r\n<p>Nelson Beebe has compiled this <a href=\"https:\/\/www.tug.org\/utah\/bibnet\/authors\/p\/parlett-beresford-n.pdf\" target=\"_blank\" rel=\"noopener\">bibliography<\/a>\r\n<\/p>\r\n<p>\r\n<img decoding=\"async\" vspace=\"5\" hspace=\"5\" src=\"https:\/\/blogs.mathworks.com\/cleve\/files\/beebe.png\" alt=\"\"> <\/p>\r\n<p>Beresford's book, <i>The Symmetric Eigenvalue Problem<\/i>, was published in 1980 by Prentice-Hall and reprinted in 1987 by SIAM.<\/p>\r\n<p>\r\n<img decoding=\"async\" vspace=\"5\" hspace=\"5\" src=\"https:\/\/blogs.mathworks.com\/cleve\/files\/sep.png\" alt=\"\"> <\/p>\r\n<script language=\"JavaScript\"> <!-- \r\n    function grabCode_ba9a4ab4bdab4d61a9801819abaacad9() {\r\n        \/\/ Remember the title so we can use it in the new page\r\n        title = document.title;\r\n\r\n        \/\/ Break up these strings so that their presence\r\n        \/\/ in the Javascript doesn't mess up the search for\r\n        \/\/ the MATLAB code.\r\n        t1='ba9a4ab4bdab4d61a9801819abaacad9 ' + '##### ' + 'SOURCE BEGIN' + ' #####';\r\n        t2='##### ' + 'SOURCE END' + ' #####' + ' ba9a4ab4bdab4d61a9801819abaacad9';\r\n    \r\n        b=document.getElementsByTagName('body')[0];\r\n        i1=b.innerHTML.indexOf(t1)+t1.length;\r\n        i2=b.innerHTML.indexOf(t2);\r\n \r\n        code_string = b.innerHTML.substring(i1, i2);\r\n        code_string = code_string.replace(\/REPLACE_WITH_DASH_DASH\/g,'--');\r\n\r\n        \/\/ Use \/x3C\/g instead of the less-than character to avoid errors \r\n        \/\/ in the XML parser.\r\n        \/\/ Use '\\x26#60;' instead of '<' so that the XML parser\r\n        \/\/ doesn't go ahead and substitute the less-than character. \r\n        code_string = code_string.replace(\/\\x3C\/g, '\\x26#60;');\r\n\r\n        copyright = 'Copyright 2026 The MathWorks, Inc.';\r\n\r\n        w = window.open();\r\n        d = w.document;\r\n        d.write('<pre>\\n');\r\n        d.write(code_string);\r\n\r\n        \/\/ Add copyright line at the bottom if specified.\r\n        if (copyright.length > 0) {\r\n            d.writeln('');\r\n            d.writeln('%%');\r\n            if (copyright.length > 0) {\r\n                d.writeln('% _' + copyright + '_');\r\n            }\r\n        }\r\n\r\n        d.write('<\/pre>\\n');\r\n\r\n        d.title = title + ' (MATLAB code)';\r\n        d.close();\r\n    }   \r\n     --> <\/script>\r\n<p style=\"text-align: right; font-size: xx-small; font-weight:lighter;   font-style: italic; color: gray\">\r\n<br>\r\n<a href=\"javascript:grabCode_ba9a4ab4bdab4d61a9801819abaacad9()\"><span style=\"font-size: x-small;        font-style: italic;\">Get \r\n      the MATLAB code <noscript>(requires JavaScript)<\/noscript>\r\n<\/span><\/a>\r\n<br>\r\n<br>\r\n      Published with MATLAB&reg; R2026a<br>\r\n<\/p>\r\n<\/div>\r\n<!--\r\nba9a4ab4bdab4d61a9801819abaacad9 ##### SOURCE BEGIN #####\r\n%% Beresford Parlett\r\n%\r\n% <<Beresford_Linocut.jpg>>\r\n%\r\n% <https:\/\/www.henkvandervorst.nl\/computing.html\r\n% Linocuts> by Henk van der Vorst.\r\n%\r\n% Beresford Parlett passed away last Saturday, February 7.\r\n% He was 93 years old.\r\n% I have known him since graduate school at Stanford.\r\n\r\n%% Stanford\r\n% <<photoNormal.jpg>>\r\n%\r\n% Source: George M. Bergman, Berkeley.\r\n%\r\n% <https:\/\/en.wikipedia.org\/wiki\/Beresford_Parlett\r\n% Beresford> was born in 1932 in London.\r\n% He received his bachelor's degree in mathematics from Oxford\r\n% in 1955.\r\n% \r\n% Beresford came to graduate school at Stanford in 1958.\r\n% He had very little money and no place to live.\r\n% At first, he slept in the math faculty women's lounge\r\n% and showered in the gymnasium. Fortunately, after two quarters,\r\n% the math made him a teaching assistant, and he was able to move out\r\n% of the lounge.\r\n%\r\n% I came to Stanford in 1961, three years after Beresford.\r\n% We were both students of <https:\/\/blogs.mathworks.com\/cleve\/2013\/01\/07\/george-forsythe\/\r\n% George Forsythe>, and are both on the\r\n% <http:\/\/infolab.stanford.edu\/pub\/voy\/museum\/forsythetree.html\r\n% Forsythe tree>.\r\n\r\n%% Career\r\n% <<parlett.jpg>>\r\n%\r\n% Source: EECS, Berkeley.\r\n%\r\n% Beresford received his Ph.D. in math from Stanford in 1962.\r\n%% \r\n% He was a postdoc for two years at NYU's Courant Institute\r\n% and for one year at the Stevens Institute of Technology\r\n%\r\n% Beresford joined the U. C Berkeley math faculty in 1965\r\n% and remained there until his retirement.\r\n\r\n%% Holy Grail\r\n% Many researchers, including Parlett, contributed to the search for\r\n% the <https:\/\/en.wikipedia.org\/wiki\/Holy_Grail Holy Grail>\r\n% of matrix eigenvalue computation, \r\n% an algorithm with O(n) time complexity.\r\n% The quest culminated in the MRRR algorithm, the subject of the\r\n% <https:\/\/www.cs.utexas.edu\/~inderjit\/Talks\/holygrail.pdf\r\n% Ph.D. thesis> of one of Beresford's students, Inderjit Dhillon. \r\n%\r\n% Beresford's specialities include\r\n%\r\n% * Matrix eigenvalues\r\n% * QR algorithm\r\n% * Lanczos algorithm\r\n% * MRRR algorithm\r\n% * Sparse matrices\r\n%\r\n% Nelson Beebe has compiled this\r\n% <https:\/\/www.tug.org\/utah\/bibnet\/authors\/p\/parlett-beresford-n.pdf\r\n% bibliography>\r\n%\r\n% <<beebe.png>>\r\n%\r\n% Beresford's book, _The Symmetric Eigenvalue Problem_, was\r\n% published in 1980 by Prentice-Hall and\r\n% reprinted in 1987 by SIAM.\r\n%\r\n% <<sep.png>>\r\n%\r\n\r\n##### SOURCE END ##### ba9a4ab4bdab4d61a9801819abaacad9\r\n-->\r\n","protected":false},"excerpt":{"rendered":"<div class=\"overview-image\"><img src=\"https:\/\/blogs.mathworks.com\/cleve\/files\/Beresford_Linocut.jpg\" class=\"img-responsive attachment-post-thumbnail size-post-thumbnail wp-post-image\" alt=\"\" decoding=\"async\" loading=\"lazy\" \/><\/div>\r\n<p>\r\n<a href=\"https:\/\/www.henkvandervorst.nl\/computing.html\" target=\"_blank\" rel=\"noopener\">Linocuts<\/a> by Henk van der Vorst.... <a class=\"read-more\" href=\"https:\/\/blogs.mathworks.com\/cleve\/2026\/02\/10\/beresford-parlett\/\">read more >><\/a><\/p>","protected":false},"author":78,"featured_media":13549,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":[],"categories":[13,4,8,1],"tags":[],"_links":{"self":[{"href":"https:\/\/blogs.mathworks.com\/cleve\/wp-json\/wp\/v2\/posts\/13544"}],"collection":[{"href":"https:\/\/blogs.mathworks.com\/cleve\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/blogs.mathworks.com\/cleve\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/blogs.mathworks.com\/cleve\/wp-json\/wp\/v2\/users\/78"}],"replies":[{"embeddable":true,"href":"https:\/\/blogs.mathworks.com\/cleve\/wp-json\/wp\/v2\/comments?post=13544"}],"version-history":[{"count":3,"href":"https:\/\/blogs.mathworks.com\/cleve\/wp-json\/wp\/v2\/posts\/13544\/revisions"}],"predecessor-version":[{"id":13554,"href":"https:\/\/blogs.mathworks.com\/cleve\/wp-json\/wp\/v2\/posts\/13544\/revisions\/13554"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/blogs.mathworks.com\/cleve\/wp-json\/wp\/v2\/media\/13549"}],"wp:attachment":[{"href":"https:\/\/blogs.mathworks.com\/cleve\/wp-json\/wp\/v2\/media?parent=13544"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blogs.mathworks.com\/cleve\/wp-json\/wp\/v2\/categories?post=13544"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blogs.mathworks.com\/cleve\/wp-json\/wp\/v2\/tags?post=13544"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}