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Articles by Nizamuddin Siddiqui
Page 68 of 196
How to check the least number of arguments a function expects in R?
To find the least number of arguments a function expects while using in R can be done with the help of the syntax: length(formals(“function_name”)). For example, to find the number of arguments expected by mutate function of dplyr package can be calculated by using the command length(formals(mutate)) but we need to make sure that the package is loaded.Exampleslibrary(ggplot2) length(formals(ggplot))Output[1] 4 length(formals(boxplot)) [1] 2 length(formals(qnorm)) [1] 5 length(formals(rnorm)) [1] 3 length(formals(rpois)) [1] 2 length(formals(runif)) [1] 3 length(formals(punif)) [1] 5 length(formals(plot)) [1] 3 length(formals(pbinom)) [1] 5 length(formals(qbinom)) [1] 5 length(formals(hist)) [1] 2 length(formals(data)) [1] 7 length(formals(matrix)) [1] 5 length(formals(list)) [1] 0 length(formals(data.frame)) ...
Read MoreWhat is the use of set.seed in R?
The set.seed helps to create the replicate of the random generation. If the name of the object changes that does not mean the replication will be changed but if we change the position then it will. Here, in the below example x4 in the first random generation and the x_4 in the second random generation with the same set.seed are same but x4 and x4 in both are different.Exampleset.seed(101) x1
Read MoreHow to create the plots arranged in a list that were generated using ggplot2 in R?
If we have two plots generated by using ggplot2 and arranged in a list then we can create them using ggarrange function. For example, if we have two objects p1 and p2 that are stored in the list called named as LIST then those plots can be created in the plot window by using the command ggarrange(plotlist=LIST,widths=c(2,1),labels=c("Scatter","Hist"))ExampleConsider the below data frame −set.seed(21) x
Read MoreHow to create a sparse matrix in R?
A sparse matrix is a type of matrix that has most of the elements equal to zero but there is no restriction for the number of zero elements. As a general criterion the number of non−zero elements are expected to be equal to the number of rows or number of columns. To create a sparse matrix in R, we can use sparseMatrix function of Matrix package.Example1i
Read MoreHow to replace NA with 0 and other values to 1 in an R data frame column?
Sometimes we want to convert a column of an R data frame to binary column using 0 and 1, it is especially done in situations where we have some NAs in the column of the data frame and the other values can be converted to 1 due to some characteristics. To replace NA with 0 and other values to 1, we can use ifelse function.Example1y1
Read MoreHow to create combinations of 0 and 1 with fixed number of 1s in each row in an R data frame?
To create the combinations of 0 and 1 data frame, we can use expand.grid function along with the rep function. If we want to create combination of 0 and 1 with fixed number of 1’s in each row then rowSums functions can be used with the appropriate sum value. For example, to have rows containing less than three 1’s, the rowSums will be extracted from grid for the same.Example1First
Read MoreHow to add a new value to each element of list in R?
Suppose we have a list that contain two elements and we get a new value for both of these elements then the problem of adding those values to the original list arises. This can be done with the help of mapply function. We can append the new values in the original easily but a vector of the new values needs to be created first.Example1List1
Read MoreHow to create a large vector with repetitive elements of varying size in R?
To create a large vector of repetitive elements of varying size we can use the rep function along with the logical vector as an index. The logical vector that contains TRUE or FALSE will define the selection or omission of the values in the vector created with the help of rep function as shown in the below examples. If the vector created by using rep is larger than the logical vector then the logical vector will be recycled.Example1x1
Read MoreHow to remove rows for categorical columns that has three or less combination of duplicates in an R data frame?
In Data Analysis, we sometimes decide the size of the data or sample size based on our thoughts and this might result in removing some part of the data. One such thing could be removing three or less duplicate combinations of categorical columns and it can be done with the help of filter function of dplyr package by grouping with group_by function.Example1y1
Read MoreHow to find the percentage of missing values in an R data frame?
To find the percentage of missing values in an R data frame, we can use sum function with the prod function. For example, if we have a data frame called df that contains some missing values then the percentage of missing values can be calculated by using the command: (sum(is.na(df))/prod(dim(df)))*100Example1y1
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