To check the trend of all columns of a data frame, we need to create line charts for all of those columns. These line charts help us to understand how data points fall or rise for the columns. Once we know the trend, we can try to find the out ... Read More

While doing the data exploration in an analytical project, we sometimes need to find the index of some values, mostly the indices of minimum and maximum values to check whether the corresponding data row has some crucial information or we may neglect it. Also, these values sometimes transformed to another ... Read More

In data analysis, time series is one of the common data we have to deal with and it might also contain dates data along with other variables. We might want to find the difference between two times to check how many days or weeks have changed the time series. This ... Read More

Regression analysis output in R gives us so many values but if we believe that our model is good enough, we might want to extract only coefficients, standard errors, and t-scores or p-values because these are the values that ultimately matters, specifically the coefficients as they help us to interpret ... Read More

In data analysis, there are many situations we have to deal with and one of them is creating a new column that has the row sums of only some rows. These sums will be repeated so that we get the total number of values equal to the number of rows ... Read More

The error “undefined columns selected when subsetting data frame” means that R does not understand the column that you want to use while subsetting the data frame. Generally, this happens when we forget to use comma while subsetting with single square brackets.ExampleConsider the below data frame −> set.seed(99) > x1 ... Read More

When we have multiple lists but they have similar type of data then we might want to combine or merge those lists. This will be helpful to use because we can perform the calculations using one list name instead of applying them on multiple ones. We can combine multiple lists ... Read More

Categorical variables have multiple categories but if the data set is large and the categories are also large in numbers then it becomes a little difficult to recognize them. Therefore, we can extract unique values for categorical variables that will help us to easily recognize the categories of a categorical ... Read More

An R data frame can have a large number of categorical variables and these categorical form different combinations. For example, one value of a variable could be linked with two or more values of the other variable. Also, one categorical variable can have all unique categories. We can find this ... Read More

Creating a data frame with a column as a list is not difficult but we need to use I with the list so that the list elements do not work as an individual column. Here, you will find the common method to create a list which is incorrect if we ... Read More