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R Programming Articles
Page 72 of 174
How to set a level of a factor column in an R data frame to NA?
In data analysis, we often face inappropriate data and hence the data analysis becomes difficult. An example of inappropriate data is reading missing values with a different value by naming them as Missing or Not Available. It can be done by using below syntax −Syntaxlevels(“data_frame_name”$”Column_name”)[levels(“data_frame_name”$”Column_name”=="Missing"]
Read MoreHow to find the maximum of factor levels in numerical column and return the output including other columns in the R data frame?
When we have factor column that helps to differentiate between numerical column then we might want to find the maximum value for each of the factor levels. This will help us to compare the factor levels in terms of their maximum and if we want to do this by getting all the columns in the data frame then aggregate function needs to be used with merge function.Consider the below data frame −Exampleset.seed(78) Group
Read MoreHow to find the position of one or more values in a vector into another vector that contains same values in R?
Finding the position of one of more values that are common in two vectors can be easily done with the help of match function. The match function will match the values in first and second vector then return the index or position of these common values in second vector.Exampleset.seed(145) x1
Read MoreHow to find the cube root of negative values in R?
There is no function in R to find the cube root of negative values, hence we need to create that. The code to create the function is as shown below −CubeRoot
Read MoreHow to combine two matrices to create a block-diagonal matrix in R?
A block-diagonal matrix means that a matrix added to another matrix at the end the last element. For example, if we have a matrix with nine values and the other matrix also has nine values then the second matrix will be added to the first matrix and the elements below first matrix will be zero and the elements above the second matrix will also be zero.ExampleM1
Read MoreHow to convert rows in an R data frame to list?
Sometimes each row needs to be treated differently, therefore, we might want to convert those rows into list. This will help us to perform the operations on our row elements separately. To convert the rows into list, we can use split function by defining the number of rows in the data frame.Consider the below data frame −Exampleset.seed(101) x1
Read MoreHow to generate a normal random vector using the mean of a vector in R?
To create a normal random vector, we can use rnorm function with mean and standard deviation as well as without passing these arguments. If we have a different vector derived from another distribution or simply represent some numbers then we can use the mean of that vector in the rnorm function for mean argument.Exampleset.seed(101) x1
Read MoreHow to take a subset of a matrix in R with finite values only if the matrix contains NA and Inf values?
If we have a matrix that contains NA or Inf values and we want to take the subset of that matrix with finite values then only the rows that do not contain NA or Inf values will be the output. We can do this in R by using rowSums and is.finite function with negation operator !.Exampleset.seed(999) M1
Read MoreHow to find 95% confidence interval for binomial data in R?
The binomial data has two parameters, the sample size and the number of successes. To find the 95% confidence interval we just need to use prop.test function in R but we need to make sure that we put correct argument to FALSE so that the confidence interval will be calculated without continuity correction. In the below examples, we have found the 95% confidence interval for different values of sample size and number of successes.Exampleprop.test(x=25, n=100, conf.level=0.95, correct=FALSE)Output1-sample proportions test without continuity correction data: 25 out of 100, null probability 0.5 X-squared = 25, df = 1, p-value = 5.733e-07 alternative ...
Read MoreHow to extract correlation coefficient value from correlation test in R?
To perform the correlation test in R, we need to use cor.test function with two variables and it returns so many values such as test statistic value, degrees of freedom, the p-value, the confidence interval, and the correlation coefficient value. If we want to extract the correlation coefficient value from the correlation test output then estimate function could be used as shown in below examples.Examplex1
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