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Articles by Nizamuddin Siddiqui
Page 58 of 196
How to remove spaces at the end in string vectors in R?
Sometimes values in a string vector has an extra space at the end, this might happen while typing the values or due to some other manual errors. To remove spaces at the end in string vectors, we can use gsub function. For example, if we have a vector called x that contains string values with spaces at the end then the removal of values can be done by using the command gsub(" $","",x,perl=T)Examplex1
Read MoreHow to find the rate of return for a vector values in R?
To find the rate of return for a vector values, we can use the formula for rate of return. For example, if we have a vector called x then the rate of return can be calculated by using the syntax diff(x)/x[-length(x)]. The output will be in decimal form and if we want to convert it to percentage then the output needs to be multiplied with 100, we can also input the same within the formula as (diff(x)/x[-length(x)])*100.Examplex1
Read MoreHow to add an extra point to scatterplot using ggplot2 in R?
To add an extra point to scatterplot using ggplot2, we can still use geom_point function. We just need to use aes function for quoting with new values for the variables, also we can change the color of this point using colour argument. The display of an extra point will help us to distinguish between a threshold/new value and remaining values.Consider the below data frame −Examplex
Read MoreHow to convert binary variable to 0/1 format in an R data frame?
A binary variable is a type of variable that can take only two possible values like gender that has two categories male and female, citizenship of a country with two categories as yes and no, etc. If the binary variable is not in 0/1 format then it can be converted with the help of ifelse function. Check out the below examples to understand how it works.Consider the below data frame −ExampleTemp
Read MoreHow to create a dummy variable in R?
A dummy variable is a type of variable that takes a value of 1 if the value for which the dummy variable is created exists in the data frame, otherwise it takes 0. Therefore, if we have a one binary variable in a data frame then there will be two dummy variables for the same. To create a dummy variable, we can use model.matrix function as shown in the below examples.Consider the below data frame −ExampleTemp
Read MoreHow to convert NaN to NA in an R data frame?
To convert NaN to NA in an R data frame, we can set the NaN values to NA values by using single square brackets. Firstly, we would need to access the column that contains NaN values then NaN values will be accessed using is.nan then we can set those values to NA as shown in the below examples.Consider the below data frame −Examplex1
Read MoreHow to extract the closest value to a certain value in each category in an R data frame?
In Data Analysis, we often deal with the comparison of values and this comparison could be also done after finding the closest value to a certain value that might be threshold. For this purpose, we can use filter function of dplyr package along with abs and min function, the abs and min function are required to create the formula for finding the closest value.Consider the below data frame −ExampleCategory
Read MoreHow to replace a complete column in an R data frame?
To replace a complete column in an R data frame, we can set the original one to new values by using delta operator. For example, if we have a data frame called df that contains a column x which 500 has values from normal distribution then to replace it with the normal distribution having a mean of 25 can be done as df$x
Read MoreHow to find the position of NA in an R vector?
When we have NA’s/missing values in an R vector then we want to replace those NA’s and for this purpose we might be needing the position of those values. These positions will be helpful especially in situations when we want to manually replace the missing values. The replacement can be done by using which function with is.na.Example1x1
Read MoreHow to remove dot and number at the end of the string in an R vector?
To remove dot and number at the end of the string, we can use gsub function. It will search for the pattern of dot and number at the end of the string in the vector then removal of the pattern can be done by using double quotes without space. After that the vector will be passed as shown in the below examples.Example1x1
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