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Articles by Nizamuddin Siddiqui
Page 85 of 196
How to create the random sample by defining the probabilities for each unit in R?
The random sample can be created by using sample function, this random sample gives equal chance for each unit to be selected in the sample, hence it is called simple random sample. If we want to have a sample where each unit has different chance of being selected in the sample then we need to use the argument prob as shown in the below examples.Example1 Live Demox1
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.Example1 Live Demox1
Read MoreHow to create correlation matrix plot in R?
To create a correlation matrix plot, we can use ggpairs function of GGally package. For example, if we have a data frame called df that contains five columns then the correlation matrix plot can be created as ggpairs(df). A correlation matrix plot using ggpairs display correlation value as well as scatterplot and the distribution of variable on diagonal.Example Live DemoConsider the below data frame −set.seed(212) x
Read MoreHow to deal with the error “Error in int_abline---plot.new has not been called yet” in R?
The above error means plot is not being created yet hence abline function cannot be used to draw anything on the plot. Therefore, a plot needs to be created first to use abline function for creating a line or any other thing. Mostly, abline is used to create regression line on the plot, thus we need to create a scatterplot first before using abline.Example Live DemoConsider the below data frame −x
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 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 −Example Live Demox1
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 −Example Live DemoTemp
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 −Example Live DemoTemp
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 −Example Live Demox
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.Example Live Demox1
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