1/11/2024 0 Comments Xline stata date format![]() gen clock = substr(time, 1, 19) generates a new variable clock with the first 19 characters of time. Let's say we have a dataset with a string variable time and we want to extract the date and time components to the seconds. Substr( s, n1, n2) extracts the substring of s from n1 for the length of n2. ” and space into four new variables substr1-substr4. split make, p("." " ") gen(substr) splits make by “. The generate() option allows one to change the prefix of the new variables to be generated. The parse() option allows one to specify the separator. Split splits string variables by separators into several components, and generates new string variables for each component taken out from the original string. gen position = strpos(make,".") creates the new variable position that gives us the position of “.” in make. When positions are not found they return 0. Strrpos( s1, s2) returns the position of s2 where last found in s1; Strpos( s1, s2) returns the position of s2 where first found in s1 UCLA: Statistical Consulting Group, How can I extract a portion of a string variable using regular expressions? | Stata FAQ * matches zero or more of the preceding expression matches at least one of the values in the bracket Ī-zA-Z matches any value of the letters, uppercase or lowercase 0-9, similarly, will match any numbers in the specified numeric range gen make2 = regexs(1) if regexm(make, "(+)(|)*(+)") takes out the car make, the first part from its make and model combination in make strings. Regexs( n) must appear after regexm( s,re) and returns the n th substring from what is previously matched by regexm( s,re). Cases with all numeric characters have been replaced by "marked". gen id2 = regexr(id, "", "marked") generates a new variable id2. ![]() Regexr( s1,re,s2) replaces the string s1 that matches the regular expression re with s2. Then if we want to drop cases with non-numeric characters, we can easily do that. If the matching is successful, it returns 1 otherwise it returns 0.įor instance, gen flag = regexm(id, "") marks observations that contain numeric characters. ![]() Regexm( s,re) performs matching on the string s by regular expression re. Turner, What are regular expressions and how can I use them in Stata? Other users who have found the question cross-posted are encouraged to share the links as a reply as well.Read how Stata’s regular expressions work: ![]() If you've asked a question, let people know where else you asked the question and what your solution(s) were! When you post a question on another platform, include those links in your questions or as a reply (if it's Discord, just mention it).See the sticked "READ ME: How to best ask for help in /r/Stata" post on how to comment here if all else fails. Make sure to include the word "Stata" in your search query. Perform a web search for your question prior to posting here. Stata's online community has been active for many years and many questions and solutions are documented on StataList, which are highly indexed on contemporary search engines (e.g., Google). Stata has extensive and complete documentation you can read before posting here (and you can type help followed by the command name in console to see it, e.g. This is not a place to find Stata tutoring. Do not request that the /r/Stata community do your homework for you. Assume good faith questions and comments. Be nice when posting or commenting to a post.The Code Block on Discord (run by Asjad Naqvi of The Stata Guide). ![]()
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