Server Side Programming Articles - Page 719 of 2650

To change the order of a matrix in increasing order based on a single column in R, we can use order function after subsetting a particular column.For example, if we have a matrix called M and we want to change the order of M in increasing order based on first column then it can be done by using the following command −M[order(M[,1]),]Example 1Following snippet creates a matrix −M1

A list may contain vectors, data frames, matrices, lists etc. If a list contains matrices and we want to convert those matrices into vectors then lapply function can be used along with as.vector function.For example, if we have a list called LIST that contains matrices then we can convert those matrices into data frames by using the below given command − lapply(LIST,function(x) as.vector(x))ExampleFollowing snippet creates the matrices −M1

To create a new column with ratio of two columns in an R data frame, we can use division sign.For example, if we have a data frame called df that contains two columns say X and Y and we want to create a new column with ratio of X and Y then we can use the below given command −df$Ratio_X_Y

To find the number of times a variable changes its sign in an R data frame column, we can use sign function with diff and sum function.For example, if we have a data frame called df that contains a column say C then, we can find the number of times C changes its sign by using the following command −sum(diff(sign(df$C))!=0)Example 1Following snippet creates a sample data frame −x

To change the color of line in xyplot, we can use col argument.For example, if we have two vectors say X and Y and we want to create a red colored xyplot between X and Y then we can use the following command −xyplot(x~y,type="l", col="red")Check out the below example to understand how it works.ExampleTo change the color of line in xyplot, use the code given below −set.seed(123) library(lattice) xyplot(1:5~rpois(5,5),type="l",col="blue")OutputIf you execute the above given code, it generates the following output −

To fill the outliers in boxplot with different color in base R, we can use outpch argument for the shape and outbg argument for colors.For example, if we have a vector called X that contains some outliers then we can create a boxplot of X with different color outliers by using the below mentioned command −boxplot(X,outpch=21,outbg="blue")ExampleTo fill the outliers in boxplot with different color in base R, use the code given below −x

To display outliers in boxplot with different shape in base R, we can use outpch argument in boxplot.For example, if we have a vector called X that contains some outliers then we can create a boxplot of X with different shape of outliers by using the below given command −boxplot(X,outpch=17)ExampleTo display outliers in boxplot with different shape in base R, use the code given below −x

To change the color of box of boxplot in base R, we can use col argument inside boxplot function.For example, if we have a vector called V and we want to create a boxplot of V without red colored box then we can use the following command −boxplot(x,col="red")ExampleTo change the color of box of boxplot in base R, use the code given below −x

To change the color of outliers in base R boxplot, we can use outcol argument in boxplot function.For example, if we have a vector called X that contains some outliers then we can create a boxplot of X with blue color outliers by using the below given command −boxplot(X,outcol="red")ExampleTo change the color of outliers in base R boxplot, use the code given below: −x

To write plot description outside plot using ggplot2, we can use annotate function and coord_cartesian function. The annotate function will define the plot description and the coord_cartesian function will define the position of the text outside the plot area.Check out the below given example to understand how it works.ExampleFollowing snippet creates a sample data frame −x