Found 2038 Articles for R Programming

How to calculate row means by excluding NA values in an R data frame?

Nizamuddin Siddiqui
Updated on 17-Oct-2020 13:59:11

2K+ Views

To find the row means we can use rowMeans function but if we have some missing values in the data frame then na.rm=TRUE argument can be used in the same way as it is used while calculating the means for columns. For example, if we have a data frame df that contains two columns x and y each having some missing values then the row means can be calculated as rowMeans(df,na.rm=TRUE).ExampleConsider the below data frame − Live Demoset.seed(1515) x1

How to change the Y axis limit for boxplot created by using ggplot2 in R?

Nizamuddin Siddiqui
Updated on 17-Oct-2020 13:57:17

2K+ Views

One of the most important aspects of a boxplot is Y-axis labels because these labels help us to understand the limit of the variable. Since R generate these labels automatically in a good way, we stick with that but we can change that using coord_cartesian function with ylim as shown in the below example.Example Live DemoConsider the below data frame −set.seed(1212) x

How to replace missing values with median in an R data frame column?

Nizamuddin Siddiqui
Updated on 17-Oct-2020 13:55:12

1K+ Views

To replace missing values with median, we can use the same trick that is used to replace missing values with mean. For example, if we have a data frame df that contain columns x and y where both of the columns contains some missing values then the missing values can be replaced with median as df$x[is.na(df$x)]

How to extract a particular value based on index from an R data frame column?

Nizamuddin Siddiqui
Updated on 17-Oct-2020 13:52:35

2K+ Views

Sometimes we want to figure out which value lies at some position in an R data frame column, this helps us to understand the data collection or data simulation process. For example, if we have a data frame df that contain columns x, y, and z each with 5000 values then we can use df$x[[253]] to find which values lies at 253rd row in column x of data frame df.ExampleConsider the below data frame − Live Demoset.seed(987) x

How to create a point chart for cumulative sums using ggplot2 in R?

Nizamuddin Siddiqui
Updated on 17-Oct-2020 13:47:12

970 Views

To create a point chart for cumulative sums using ggplot2, we need to use cumsum function for the dependent variable inside the aes function for aesthetic mapping that describes how the variable will be plotted. For example, if we have a data frame df that contain columns x and y where y is the dependent variable then the point chart for cumulative sums can be created as ggplot(df,aes(1:20,y=cumsum(y)))+geom_point().ExampleConsider the below data frame − Live Demoset.seed(666) x

How to combine two lists of same size to make a data frame in R?

Nizamuddin Siddiqui
Updated on 17-Oct-2020 13:32:11

820 Views

If we have two lists of same size then we can create a data frame using those lists and this can be easily done with the help of expand.grid function. The expand.grid function create a data frame from all combinations of the provided lists or vectors or factors. For example, if we have two lists defined as List1 and List2 then we can create a data frame using the code expand.grid(List1,List2).Example Live DemoConsider the below lists −List1

How to multiply two vectors in R as in mathematics?

Nizamuddin Siddiqui
Updated on 17-Oct-2020 13:29:28

5K+ Views

In mathematics, when two vectors are multiplied the output is a scalar quantity which is the sum of the product of the values. For example, if we have two vectors x and y each containing 1 and 2 then the multiplication of the two vectors will be 5. In R, we can do it by using t(x)%*%y.Example1 Live Demox1

How to create a random sample with values 0 and 1 in R?

Nizamuddin Siddiqui
Updated on 17-Oct-2020 14:30:01

1K+ Views

It is known that the random sample can be created by using sample function in R. If we want to create a random sample with values 0 and 1 only then there are three different ways to pass them inside the sample function −Creating a vector of 0 and 1Using 0:1Using c(1,2) directly inside the function.Also, we can set replace argument to TRUE or FALSE based on our requirement.Examples Live Demox1

How to find the mean of list elements in R?

Nizamuddin Siddiqui
Updated on 17-Oct-2020 13:21:52

4K+ Views

To find the mean of list elements we need to unlist those elements. For example, if we have a list named as List that contains three elements of equal or different sizes such element1, element2, and element3 then we can find the mean of all the list elements by using mean(unlist(List)).Example1List1

How to replace blanks in a vector with the previous element in R?

Nizamuddin Siddiqui
Updated on 17-Oct-2020 13:18:27

111 Views

Filling of blanks is not an easy task in data analysis, especially if the vector contains numerical or integer values. Suppose we have a vector x that contains 1, , 2, 3, 4, 5 and we want to put 1 in place of blank after first value then cummax function along with seq_along function can be used as x[cummax(seq_along(x)*(x!=""))].Example1 Live Demox1

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