We can use stri_sub function in stringi package.Example> x x [1] "TutorialsPoint is the largest online library for best tutorials" > library(stringi) > stri_sub(x, 1, 9) [1] "Tutorials" > stri_sub(x, 1, -20) [1] "TutorialsPoint is the largest online library" > stri_sub(x, -14, -1) [1] "best tutorials" > stri_sub(x, -41, -1) ... Read More

To check whether a string is a subset of another string we can use grepl function.Example> Company Job grepl(Job, Company, fixed = TRUE) [1] TRUEHere we are getting TRUE because Tutor is a subset of TutorialsPoint.> grepl(Company, Job, fixed = TRUE) [1] FALSEHere we are getting FALSE because ... Read More

This can be done by using tail function.Example> x tail(x,n=1) [1] 1095 > data tail(data,n=1) Class 10 PhD df = data.frame(matrix(rnorm(20), nrow=5)) > tail(df,n=1) X1 X2 X3 X4 5 -0.3595053 0.9943738 0.959761 -0.6565688 > tail(df$X4,n=1) [1] -0.6565688

We can use options(scipen=999) to do this.Example> x t.test(x, mu=2000)One Sample t-testdata: x t = -14.212, df = 9, p-value = 1.801e-07 alternative hypothesis: true mean is not equal to 200095 percent confidence interval −151.3501 659.0499sample estimates −mean of x 405.2Here p-value is in scientific notation. Now we can ... Read More

This can be done by setting the levels of the variable in the order we want.Example> data data ggplot(data, aes(x = Class)) + geom_bar()Setting the levels in increasing order> data

Reordering of columns can be done by using square brackets.Example> df = data.frame(matrix(rnorm(20), nrow=5)) > df       X1       X2       X3       X4 1 -0.3637644 2.0770246 0.48763128 -0.09019256 2 -3.1758515 2.3173075 0.86846761 0.38396459 3 1.1844641 0.3412267 1.90986295 -1.03493074 4 -0.5953466 1.7211738 ... Read More

There are three ways to find the index of an element in a vector.Example> x x [1] 8 10 9 6 2 1 4 7 5 3Using which> which(x == 6)[[1]] [1] 4Here we found the index of 6 in vector x.Using match> match(c(4, 8), x) [1] 7 1Here ... Read More

This can be done simply by using sample function.Example> df = data.frame(matrix(rnorm(20), nrow=5)) > df X1 X2 X3 X4 1 -0.3277833 -0.1810403 ... Read More

We can do this by defining the newname as shown below −> Samp Samp sample.1.100..10. 1 47 2 63 3 57 4 16 5 53 6 7 7 54 8 2 9 13 10 14 > colnames(Samp) Samp Sampled Values 1 47 2 63 3 57 4 16 5 53 6 7 7 54 8 2 9 13 10 14 Since we only have one column in the data frame, so it is sufficient to use the object name.

The easiest way to add zeros before numbers is by using paste0 functionExample> ID Gender Lens data data ID Gender Lens 1 25499 1 0.8 2 25500 2 1.2 3 25501 2 1.0 4 25502 1 2.0 5 25503 2 1.8 6 25504 1 1.4Let’s say we want to add 00 before every ID.It can be done by using paste0 function as follows −> IDs newdata newdata IDs Gender Lens 1 0025499 1 0.8 2 0025500 2 1.2 3 0025501 2 1.0 4 0025502 1 2.0 5 0025503 2 1.8 6 0025504 1 1.4