Article Categories
- All Categories
-
Data Structure
-
Networking
-
RDBMS
-
Operating System
-
Java
-
MS Excel
-
iOS
-
HTML
-
CSS
-
Android
-
Python
-
C Programming
-
C++
-
C#
-
MongoDB
-
MySQL
-
Javascript
-
PHP
-
Economics & Finance
Articles by Nizamuddin Siddiqui
Page 29 of 196
How to replicate whole data frame and add it in the original one in R?
The replicates of a data frame in R can be created with the help of sapply function, to set the number of times we want to repeat the data frame we can use rep.int,times argument. For example, if we have a data frame df and we want to create 5 replicates of df and add them in the original then sapply(df,rep.int,times=5) can be used.Examplesapply(df,rep.int,times=5)Output x1 x2 x3 x4 [1,] 20.84538 9.486324 2.961236 967.9296 [2,] 23.29721 5.344792 3.044849 960.2204 [3,] 20.55978 6.064207 3.005293 1086.9639 [4,] 20.66044 8.436004 2.892010 1029.8222 [5,] 19.81347 9.277129 2.980567 1018.0453 [6,] 20.84538 9.486324 2.961236 967.9296 [7,] 23.29721 5.344792 3.044849 960.2204 [8,] 20.55978 6.064207 3.005293 1086.9639 [9,] 20.66044 8.436004 2.892010 1029.8222 [10,] 19.81347 9.277129 2.980567 1018.0453 [11,] 20.84538 9.486324 2.961236 967.9296 [12,] 23.29721 5.344792 3.044849 960.2204 [13,] 20.55978 6.064207 3.005293 1086.9639 [14,] 20.66044 8.436004 2.892010 1029.8222 [15,] 19.81347 9.277129 2.980567 1018.0453 [16,] 20.84538 9.486324 2.961236 967.9296 [17,] 23.29721 5.344792 3.044849 960.2204 [18,] 20.55978 6.064207 3.005293 1086.9639 [19,] 20.66044 8.436004 2.892010 1029.8222 [20,] 19.81347 9.277129 2.980567 1018.0453 [21,] 20.84538 9.486324 2.961236 967.9296 [22,] 23.29721 5.344792 3.044849 960.2204 [23,] 20.55978 6.064207 3.005293 1086.9639 [24,] 20.66044 8.436004 2.892010 1029.8222 [25,] 19.81347 9.277129 2.980567 1018.0453
Read MoreHow to align the bars of a barplot with the X-axis using ggplot2 in R?
The bar plot is created with geom_bar function but there always exist some space between the bars and the X-axis labels. If we want to reduce that space or completely remove it we need to use scale_y_continuous function by defining expand argument for former and scale_y_continuous(expand=c(0,0)) for latter.Exampleggplot(df,aes(x,y))+geom_bar(stat="identity")+scale_y_continuous(expand=c(0,0))Output
Read MoreHow to perform group-wise linear regression for a data frame in R?
The group−wise linear regression means creating regression model for group levels. For example, if we have a dependent variable y and the independent variable x also a grouping variable G that divides the combination of x and y into multiple groups then we can create a linear regression model for each of the group. In R, we can convert data frame to data.table object, this will help us to create the regression models easily.Exampledf2[,as.list(coef(lm(Salary~Ratings))),by=Class]OutputClass (Intercept) Ratings 1: I 31894.13 194.9152 2: III 35270.10 663.4089 3: II 40405.42 -1087.9103
Read MoreHow to find the total of frequency based on the values of a factor column in R?
Often, we have duplicate values in a factor column that means a factor column has many levels and each of these levels occur many times. In this situation, if we have a frequency column then we want to find the total of that frequency based on the values of a factor column and this can be done by using aggregate function.Example> Metal Quantity df2 head(df2, 10) Metal Quantity 1 Iron 43 2 Nickel 33 3 Lead 25 4 Zinc 24 5 Tin 27 6 Sodium 34 7 Silver ...
Read MoreHow to create a step histogram using ggplot2 in R?
To create a step histogram using ggplot2, we can use geom="step" argument inside stat_bin function. For example, if we have a data frame that contains a single column then the step histogram can be created using the command − ggplot(df,aes(x))+stat_bin(geom="step",bins=30)Examplelibrary(ggplot2) ggplot(df,aes(x))+stat_bin(geom="step",bins=30)Output
Read MoreHow to display star for significance in base R boxplot?
To display the star for significance in a base R boxplot, we can use text function. The text function will be helpful in defining the star sign (that is asterisk or *). If the significance is high then three stars are used and the significance is low then a single star is used. We need to use the appropriate position using x and y values.Exampletext(x=1,y=max(df$y[df$x==1]),"***",pos=3,cex=1.5)Output
Read MoreHow to divide the data frame rows in R by row standard deviation?
To divide the data frame row values by row standard deviation in R, we can follow the below steps −First of all, create a data frame.Then, use apply function to divide the data frame row values by row standard deviation.Creating the data frameLet's create a data frame as shown below −> x y df dfOn executing, the above script generates the below output(this output will vary on your system due to randomization) − x y 1 1.48 0.86 2 -0.14 -0.58 3 -0.25 1.22 4 0.18 0.25 5 0.50 0.68 6 -1.34 -0.21 ...
Read MoreHow to extract the factor levels from factor column in an R data frame?
To extract the factor levels from factor column, we can simply use levels function. For example, if we have a data frame called df that contains a factor column defined with x then the levels of factor levels in x can be extracted by using the command levels(df$x). This extraction is helpful if we have a large number of levels.Example1x2
Read MoreHow to create bar chart based on two groups in an R data frame?
To create a bar chart based on two groups, we can use geom_bar function of ggplot2 package with position argument that defines the position of the groups. For example, if we have a data frame called df that contains two categorical variable x1 and x2 and the one response variable y then the bar chart can be created by using the below command −ggplot(df,aes(x1,y,fill=x2))+geom_bar(position=position_dodge(),stat="identity")Examplelibrary(ggplot2) ggplot(df,aes(Age_Group,Y,fill=Gender))+geom_bar(position=position_dodge(),stat="identity")Output
Read MoreHow to find the row and column position of a value as vector in an R matrix?
To find the row and column position of a value as vector in an R matrix, we can follow the below steps −First of all, create a matrix.Then, find the row and column position of a particular value using which function and reading the output with as.vector function.Example 1Create a matrixLet's create a matrix as shown below −M1
Read More