Generally, when we add a new column to an existing R data frame that column is added at the end of the columns but we might need it at the front. This totally depends on our ease of use, familiarity with variables, and their need. We can add a new ... Read More

A matrix has only numeric values and sometimes these values are either incorrectly entered or we might want to replace some of the values in a matrix based on some conditions. For example, if we have few fives in a matrix then we might want to replace all fives to ... Read More

Generally, we extract columns as a vector from an R data frame but sometimes we might need a column as a data frame, therefore, we can use as.data.frame to extract columns that we want to extract as a data frame with single square brackets. The purpose behind this could be ... Read More

When we use par(mfrow), we define the number of plots we want to draw on the plot window and when we draw all the necessary plots then starts again with the first plot. For example, if we set par(mfrow) to (2, 2) then we will have four plots on the ... Read More

A matrix contains only numeric values, therefore, if we will convert a data frame that has factor variables as strings then the factor levels will be converted to numbers. These numbering is based on the first character of the factor level, for example, if the string starts with an A ... Read More

When we create a scatterplot or any other plot and the values are presented in scientific form in the original data then the axes values of the plot are also plotted in scientific form. This makes the plot ambiguous, therefore, reading the plot or interpreting it becomes difficult. Hence, we ... Read More

A bar plot is one of the most commonly used plots for categorical data and it can be easily done in R with the help of ggplot2. When we create a bar plot using ggplot2, there exists some space between bars and the X-axis and the largest bar and top ... Read More

If we want to provide more information about the data, we have in columns of an R data frames then we might want to use prefixes. These prefixes help everyone to understand the data, for example, we can use data set name as a prefix, the analysis objective as a ... Read More

Sometimes, we want to use some columns of an R data frame for analysis, therefore, it is better to get a list of all the columns that we need. In this way, we don’t have to worry about the column operations, if required because we will be having only necessary ... Read More

Scatterplot helps us to identify the linear relationship between two variables and it is the first step of determining a predictive model. Before using any predictive modeling technique we must draw a scatterplot between independent and dependent variables to check what kind of relationship exists between them. A scatterplot generally ... Read More