{"id":862,"date":"2013-01-22T12:57:43","date_gmt":"2013-01-22T16:57:43","guid":{"rendered":"http:\/\/www.hargaden.com\/enda\/?p=442"},"modified":"2013-01-22T12:57:43","modified_gmt":"2013-01-22T16:57:43","slug":"sample-skewness-and-kurtosis-in-r","status":"publish","type":"post","link":"https:\/\/hargaden.com\/enda\/sample-skewness-and-kurtosis-in-r\/","title":{"rendered":"Sample Skewness and Kurtosis in R"},"content":{"rendered":"<p>These are external functions to calculate skewness and kurtosis for a vector in R. Anyone using R is likely able to write similar functions themselves, but you never know.<\/p>\n<p>[code]<\/p>\n<p>### sample_skew.R<br \/>\n### Enda Hargaden, January 2013<\/p>\n<p>sample_skew = function(data_vec_dirty)<br \/>\n{<\/p>\n<p># Remove missing values<br \/>\ndata_vec = data_vec_dirty[!is.na(data_vec_dirty)]<\/p>\n<p>n = length(data_vec)<br \/>\nxbar = mean(data_vec)<\/p>\n<p>second_moment = c()<br \/>\nthird_moment = c()<\/p>\n<p>for(i in 1:n)<br \/>\n {<br \/>\n second_moment[i] = (data_vec[i] &#8211; xbar) ^ 2<br \/>\n third_moment[i] = (data_vec[i] &#8211; xbar) ^ 3<br \/>\n }<\/p>\n<p>s_numerator = sum(third_moment) \/ n<br \/>\ns_denominator = sum(second_moment \/n) ^ 1.5<br \/>\nskew = s_numerator \/ s_denominator<\/p>\n<p>skew<br \/>\n}<\/p>\n<p>[\/code]<\/p>\n<p>&nbsp;<\/p>\n<p>[code]<\/p>\n<p>### sample_kurtosis.R<br \/>\n### Enda Hargaden, January 2013<\/p>\n<p>sample_kurtosis = function(data_vec_dirty)<br \/>\n{<\/p>\n<p>#Remove missing values<br \/>\ndata_vec = data_vec_dirty[!is.na(data_vec_dirty)]<\/p>\n<p>n = length(data_vec)<br \/>\nxbar = mean(data_vec)<\/p>\n<p>second_moment = c()<br \/>\nforth_moment = c()<\/p>\n<p>for(i in 1:n)<br \/>\n {<br \/>\n second_moment[i] = (data_vec[i] &#8211; xbar) ^ 2<br \/>\n forth_moment[i] = (data_vec[i] &#8211; xbar) ^ 4<br \/>\n }<\/p>\n<p>k_numerator = sum(forth_moment) \/ n<br \/>\nk_denominator = ( sum(second_moment) \/n )^2<br \/>\nkurtosis = k_numerator \/ k_denominator<\/p>\n<p>kurtosis<\/p>\n<p>}<\/p>\n<p>[\/code]<\/p>\n","protected":false},"excerpt":{"rendered":"<p>These are external functions to calculate skewness and kurtosis for a vector in R. Anyone using R is likely able to write similar functions themselves, but you never know. [code] ### sample_skew.R ### Enda Hargaden,&hellip;<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[9],"tags":[],"class_list":["post-862","post","type-post","status-publish","format-standard","hentry","category-economics"],"_links":{"self":[{"href":"https:\/\/hargaden.com\/enda\/wp-json\/wp\/v2\/posts\/862","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/hargaden.com\/enda\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/hargaden.com\/enda\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/hargaden.com\/enda\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/hargaden.com\/enda\/wp-json\/wp\/v2\/comments?post=862"}],"version-history":[{"count":0,"href":"https:\/\/hargaden.com\/enda\/wp-json\/wp\/v2\/posts\/862\/revisions"}],"wp:attachment":[{"href":"https:\/\/hargaden.com\/enda\/wp-json\/wp\/v2\/media?parent=862"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/hargaden.com\/enda\/wp-json\/wp\/v2\/categories?post=862"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/hargaden.com\/enda\/wp-json\/wp\/v2\/tags?post=862"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}