![\"Numeric](\"https:\/\/data-flair.training\/blogs\/wp-content\/uploads\/sites\/2\/2017\/12\/Numeric-and-Character-Functions-in-R-2.jpg\")
<\/a><\/p>\nSo, let’s start the R numeric and character functions tutorial.<\/p>\n
R Built-in Functions<\/h2>\n
We use R built-in functions to perform almost everything in R. Here we are only referring to numeric and character functions that are generally used in creating or recording variables.<\/p>\n
Wait! Have you checked – R Vector Functions<\/a><\/strong><\/em><\/p>\n Let us see R\u00a0Numeric functions: \u00a0 \u00a0 \u00a0Function\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 Description<\/b><\/p>\n Let us see various R character functions:<\/p>\n 1. grep(pattern, x , ignore.case=FALSE, fixed=FALSE)<\/strong><\/p>\n Description:<\/strong><\/p>\n Output:<\/strong><\/p>\n 2.\u00a0substr(x, start=n1, stop=n2)<\/strong><\/p>\n Description:<\/strong><\/p>\n Output:<\/strong><\/p>\n You must definitely explore the R Recursive Function Tutorial<\/a><\/strong><\/em><\/p>\n 3. strsplit<\/strong><\/p>\n Output:<\/strong><\/p>\n 4.\u00a0sub(pattern, replacement, x, ignore.case =FALSE, fixed=FALSE)<\/strong><\/p>\n Description:<\/strong><\/p>\n Output:<\/strong><\/p>\n 5. toupper(string)<\/strong><\/p>\n Description:<\/b><\/p>\n Uppercase<\/p>\n Output:<\/strong><\/p>\n Do you know about Object Oriented Programming in R<\/a><\/strong><\/em><\/p>\n 6.\u00a0tolower(string)<\/strong><\/p>\n Description:<\/strong><\/p>\n Lowercase<\/p>\n Output:<\/strong><\/p>\n 7. paste(…, sep=””)<\/strong><\/p>\n Description:<\/b><\/p>\n Concatenate strings after using sep string to separate them.<\/p>\n Output:<\/strong><\/p>\n In R, we store strings in a character vector. We can create strings with a single quote\/ double quote. For example –<\/b>\u00a0y = \u201cHadoop at DataFlair\u201d<\/span><\/p>\n We use an as.character function that converts arguments to a character type. For example<\/b> – We are storing 20 as a character.<\/span><\/p>\n Output:<\/strong><\/p>\n The class(Y) returns character as 20 and is stored as a character in the above code.<\/p>\n Explore all the Types of Arguments in R<\/a><\/strong><\/em><\/p>\n Output:<\/strong><\/p>\n There are other functions that are similar to is.character such as is.integer, is.array and is.character for validating integer, array and character data types respectively.<\/p>\n In order to join the two strings (also known as concatenation), we make use of the paste function. <\/span>It is one of the most important strings manipulation task. Every analyst performs it almost daily to structure the data.<\/span> Paste Function Syntax:<\/b><\/p>\n For example<\/b>:<\/span><\/p>\n Output:<\/strong><\/p>\n Understand the String Manipulation Function in R<\/a><\/strong><\/em><\/p>\n Suppose the value is stored in fraction and you need to convert it to percentage. In order to format our string in a C-style, sprintf function is used. Sprintf Function Syntax:<\/b><\/p>\n The keyword fmt denotes string format. The numbers and letters in the format start with the % symbol.<\/p>\n Output:<\/strong><\/p>\n substr Syntax <\/b>– <\/span><\/p>\n In the above example, we are telling R<\/a> to replace first 3letters with 111.<\/p>\n Replace Substring<\/b> – substr(x, starting position, end position) = Value<\/span><\/p>\n Output:<\/strong><\/p>\n The <\/span>nchar<\/b> function is used to compute the length of a character value.<\/span><\/p>\n Output:<\/strong><\/p>\n It returns 14 as the vector ‘x’ contains 14 letters (including 2 spaces).<\/p>\n Don’t forget to check the R Statistics Tutorial<\/a><\/strong><\/em><\/p>\n Suppose you need to pull a first or last word from a character string. Word Function Syntax (Library : stringr)<\/b><\/p>\n For example<\/b>:<\/span><\/p>\n In the example above, ‘1’ denotes the first word to be extracted from a string. Extract Last Word<\/b><\/p>\n In the example above, ‘-1’ denotes the first word to be extracted from the right of the string.<\/p>\n Output:<\/strong><\/p>\n At many times, we need to change the case of a word. For example<\/b>: convert the case to uppercase or lowercase.<\/span><\/b><\/p>\n The tolower() function converts letters in a string to lowercase.<\/p>\n toupper(x) The toupper() function converts letters in a string to uppercase.<\/p>\n library(stringr)<\/p>\n The str_to_title() function converts the first letter in a string to uppercase and the remaining letters to lowercase.<\/p>\n Output:<\/strong><\/p>\n Grab the list of R Debug Functions<\/a><\/strong><\/em><\/p>\n We can use strrep base R function to repeat the character N times.<\/p>\n Output:<\/strong><\/p>\n The str_detect() function helps to check whether a substring exists in a string. It is equal to ‘contain’ function of SAS. It returns TRUE\/FALSE against each value.<\/p>\n Output:<\/strong><\/p>\n In the case of text mining, it is required to split a string to calculate the used keywords in the list.\u00a0We use ‘strsplit()’ in base R to perform this operation.<\/p>\n Output:<\/strong><\/p>\nR Numeric Functions<\/h2>\n
\n<\/b><\/p>\n\n
Character Functions in R<\/h2>\n
\n
> grep(\"A\", c(\"b\", \"A\", \"c\"), fixed = TRUE)<\/pre>\n
<\/a><\/p>\n\n
> string = \"abcdef\"\r\n> substr(string,2,4)\r\n\r\n> substr(string,2,4) <- \"2222\"\r\n> string<\/pre>\n
<\/a><\/p>\n> strsplit(\"abc\", \"\")<\/pre>\n
<\/a><\/p>\n\n
sub(\"\\\\s\",\".\",\"DataFlair\")<\/pre>\n
<\/a><\/p>\n> toupper(string)<\/pre>\n
<\/a><\/p>\n> tolower(string)<\/pre>\n
<\/a><\/p>\n> paste(\"string\", 1:3, sep = \"\")\r\n\r\n> paste(\"string\", 1:3, sep = \"M\")\r\n\r\n> paste(\"Today is\", date())<\/pre>\n
<\/a><\/p>\nR Character Function – Create Strings<\/h2>\n
\n<\/b><\/p>\n1. Convert Object into Character type<\/h4>\n
\n<\/b><\/p>\nY = as.character(20)\r\nclass(Y)<\/pre>\n
<\/a><\/p>\n2. Check the character type<\/h4>\n
> X = \u201cHadoop at DataFlair\u201d\r\n> is.character(X)<\/pre>\n
<\/a><\/p>\n3. Concatenate Strings in R<\/h4>\n
\n<\/b><\/p>\npaste (objects, sep = \" \", collapse = NULL)<\/pre>\n
\n
\n<\/b><\/li>\n<\/ul>\n> x = \"DataFlair\"\r\n> y = \"Big Data\"\r\n> paste(x,y)<\/pre>\n
<\/a><\/p>\n4. String Formatting in R<\/h4>\n
\n<\/b><\/p>\nsprintf(fmt, ...)<\/pre>\n
x = 0.25\r\nsprintf(\"%.2f%%\",x*100)<\/pre>\n
<\/a><\/p>\n5.\u00a0Extract or replace substrings in R<\/h4>\n
> name = \"abcdef\" #Author DataFlair\r\n> substr(name,1,4)\r\n<\/b><\/pre>\n
> substr(name,1,3) = \"11\" \r\n#Replacing Substring \r\n> name<\/pre>\n
<\/a><\/p>\n6. String Length<\/h4>\n
> x = \"Big Data at DataFlair\"\r\n> nchar(x)<\/pre>\n
<\/a><\/p>\n7. Extract word from a programming<\/h4>\n
\n<\/b><\/p>\nword(string, position of word to extract, separator)<\/pre>\n
> name = \"Big Data DataFlair\"\r\n> library(stringr)\r\n> word(name,1)<\/pre>\n
\n<\/b><\/p>\n> word(name,-1) #Extracting Last Word<\/pre>\n
<\/a><\/p>\n8. Convert Character to Uppercase \/ Lowercase \/Propercase<\/h4>\n
\n<\/b><\/p>\n> name = \"Big Data DataFlair\"\r\n> tolower(name) #lowercase<\/pre>\n
\n<\/b><\/p>\n> toupper(name) #UPPERCASE<\/pre>\n
> library(stringr)\r\n> str_to_title(name) #Title Case<\/pre>\n
<\/a><\/p>\n9. Repeat the character N times<\/h4>\n
> strrep(\"DataFlair\", 5)<\/pre>\n
<\/a><\/p>\n10. Find String in a Character Variable<\/h4>\n
> names = c(\"DataFlair\", \"Hadoop\", \"Spark\", \"Flink\")\r\n> library(stringr)\r\n> str_detect(names, \"DataFlair\")<\/pre>\n
<\/a><\/p>\n11. Splitting a Character Vector<\/h4>\n
> sentence <- \"Big Data at DataFlair\"\r\n> strsplit(sentence, \"\")<\/pre>\n