By default, a histogram drawn in base R has black color borders around bars. We might want to remove these black borders to make the histogram visually smooth. This can be done by using lty argument with the hist function. For example, if we have a vector x and we want to create a histogram of x without border of bars then we can use the argument as hist(x,lty="blank").Example> x hist(x)Output:Creating histogram of x without border of bars:Example> hist(x,lty="blank")Output:

To create an S4 object, we can use setClass function where we will pass the object name, column names, and the type of the data that will be stored in the columns. For example, if we want to create an S4 with name data and two numerical columns called by x and y then we can use setClass("data", representation(x1="numeric", x2="numeric")).Example1> setClass("data1", representation(x1="numeric", x2="numeric")) > data1 data1OutputAn object of class "data1" Slot "x1": [1] -0.586187627 0.853689097 -0.602612795 -2.194235741 -1.318522292 [6] -0.984882420 0.273584140 0.364691611 1.025472248 1.198547297 [11] -0.709282551 -0.001441127 -0.201348012 1.296811172 1.520093861 [16] 2.071031215 0.472877022 0.616211695 0.642165615 -0.122773000 Slot "x2": [1] ... Read More

We can find subsets using many ways in R and the easiest way is to use single-square brackets. If we want to subset a row or a number of consecutive or non-consecutive rows then it can be directly done with the data frame name and the single-square brackets. For example, if we have a data frame called df and we want to subset 1st row of df then we can use df[1, ] and that’s it.ExampleConsider the below data frame:Live Demo> set.seed(214) > x y z a b c q w df1 df1Outputx y z a b c q w ... Read More

We can create a point chart using ggplot2 package but that point not necessarily to be in circular shape, we have twenty-five shape options for those points in ggplot2. While creating a point chart using ggplot2, we can use shape argument inside geom_point to see the difference among these twenty-five shapes.ExampleConsider the below data frame:Live Demo> set.seed(1957) > x y df dfOutput x y 1 0.7028704 1.6664500 2 0.9672393 1.0456639 3 1.3102736 0.2495795 4 0.3389941 0.2141513 5 0.5867095 0.4417377 6 0.4257543 0.6533757 7 0.9106756 0.3611954 8 1.0444729 1.3770588 ... Read More

The chi square test for goodness of fit is a nonparametric test to test whether the observed values that falls into two or more categories follows a particular distribution of not. We can say that it compares the observed proportions with the expected chances. In R, we can perform this test by using chisq.test function. Check out the below examples to understand how it is done.Example1Live Demo> x1 x1Output[1] 9 4 1 9 6 6 1 6 0 0 5 8 8 3 7 8 0 3 3 9 6 0 3 8 2 0 8 5 9 1 3 ... Read More

The chartr function in base R helps us to replace old strings with new strings and hence it can be also used to replace a subs-string with the reverse of that substring. For example, if we have a vector say x that contains tutorialpsoint and we want to convert it to tutorialspoint then it can be done as chartr("tutorialpsoint ", " tutorialspoint ", x).Example1Live Demo> x1 x1Output[1] "IDNIA"Example> chartr("DN", "ND", x1)Output[1] "INDIA" Example2Live Demo> x2 x2Output[1] "IDNIA" "IDNIA" "IDNIA" "IDNONESIA" "IDNIA" "IDNONESIA" [7] "IDNONESIA" "IDNIA" "IDNONESIA" "IDNIA" "IDNIA" "IDNONESIA" [13] "IDNONESIA" "IDNONESIA" "IDNIA" "IDNONESIA" "IDNIA" "IDNIA" [19] "IDNONESIA" "IDNONESIA" "IDNIA" ... Read More

If we have many lists but we want to use the values in the lists as a vector then we first need to combine those lists and create a vector. This can be done by using unlist function along with the combine function c to create the vector. For example, if we have two lists defined as List1 and List2 and we want to create a vector V using these lists then it can be created as:V x1 x1Output$a [1] -0.6972237 -1.5013768 -0.2451809 -0.2365569 -1.6304919 -1.1704378 [7] 1.1617054 -0.2349498 -1.2582229 0.4112065 $b [1] 2 0 2 6 0 0 ... Read More

The main title of a histogram in base R can be inserted by using title function and if we want to have it in the outer margin then outer argument must be set to TRUE. If the outer argument does not fulfil our requirement then we can use par function to adjust the outer margin area and create the histogram. Check out the below example to understand how it works.Example> x hist(x) > title('Normal Distribution',outer=TRUE)OutputExample> par(oma=c(0,0,2,0)) > hist(x) > title('Normal Distribution',outer=TRUE)Output

When the assumptions of parametric analysis are not satisfied then we move on to non-parametric analysis and non-parametric analysis often deals with the calculation of median because the data is not normally distributed. If we want to find the group-wise median and the data is stored in a data.table object then lapply function can be used as shown in the below examples.ExampleLoading data.table package:> library(data.table)Consider the below data.table object:Example> Group x1 x2 x3 x4 dt1 dt1OutputGroup x1 x2 x3 x4 1: B 0.515370827 6.174187 542.9350 50.28300 2: B 0.522858146 6.976872 510.5568 49.71331 3: A 1.055456751 3.192242 476.7693 48.88280 4: A ... Read More

If we have a matrix then we might want to convert it to matrix with single column for some analytical purpose such as multiplying with a vector that has the length equal to the total number of elements as in the matrix. Thus, the matrix can be converted to a single column matrix by using matrix function itself but for this we would need to nullify the column names and row names.Example1Live Demo> M1 M1Output [, 1] [, 2] [, ... Read More