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Page 1227 of 2109
How to split a data frame in R with conditional row values?
The splitting of data frame is mainly done to compare different parts of that data frame but this splitting is based on some condition and this condition can be row values as well. For example, if we have a data frame df where a column represents categorical data then the splitting based on the categories can be done by using subset function as shown in the below examples.Example1Consider the below data frame:> Country Ratings df1 df1Output Country Ratings 1 India 1 2 China 2 3 Russia 5 4 Sudan 3 5 India 5 6 China 5 ...
Read MoreHow to create an only interaction regression model in R?
Mostly, we start with creating models by including single independent variables effect on the dependent variable and then move on to interaction. But if we are sure that there exists some interaction among variables and we are looking for the interaction effect then only interaction regression model can be created. This can be done by using colon sign between variables to signify the interaction as shown in the below examples.Example1Consider the below data frame:> x1 x2 x3 y df1 df1Outputx1 x2 x3 y 1 1 3 10 8 2 0 3 9 11 3 1 1 6 5 4 1 ...
Read MoreHow to find the mean of very small numbers in numeric form that are represented with scientific notation in R?
If we find the mean of scientific numbers then the result will be also in scientific notation. We can get rid of this problem by using options(scipen=999), once we will use this code in R console all the inputs that are in scientific notation will be converted to normal numeric form, including any calculation and if we want to go back to the scientific notation then options(scipen=0) can be used.Example> x1 mean(x1)Output[1] 4.436267e-22Example> options(scipen=999) > mean(x1)Output[1] 0.0000000000000000000004436267Example> x2 x2Output[1] 0.000000000000000000000000000000000000001010964 [2] 0.000000000000000000000000000068291679999999998 [3] 0.000000000000000000000000006026013000000000181 [4] 0.000000000000000000000000002702241000000000107 [5] 0.000000000000000000000042258669999999998179163 [6] 0.000000000000000000000000000000091949710000000 [7] 0.000000000000000000000000000000000000107406400 [8] 0.000000000000000000000000000000091949710000000 [9] 0.000000000000000000000003463124999999999951636 [10] 0.000000000000000000004305051000000000103323794 [11] 0.000000000000000000000001542657000000000059366 ...
Read MoreHow to create a random vector in R that sums to 1?
To create a random vector that sums to 1, we can use uniform distribution. The main thing that needs to be done cautiously is we should include 0 in the vector with randomly generating uniform distribution values. Check out the below examples to understand how it can be done.Example1> x1 x1Output[1] 0.45490995 0.23826247 -0.07338489 -0.33361362 0.26125094 -0.45243689 [7] 0.05967125 0.43007076 0.04069027 0.37457976Example> sum(x1)Output[1] 1Example2> x2 x2Output[1] 1.84330339 -0.11622911 -0.15001654 0.07803346 -0.17353612 0.23651847 [7] -0.21121933 -0.30938763 0.44503222 -0.64249881Example> sum(x2)Output[1] 1Example3> x3 x3Output[1] 2.63249755 1.17230387 -0.28068787 0.58040911 -1.48530836 -0.04894802 [7] 0.66718009 0.13504265 -0.18253891 -0.49757615 1.63580429 -2.31002917 [13] 2.66256899 -2.40636756 2.03789127 0.13579276 -0.75107129 ...
Read MoreHow to standardized a column in an R data frame?
The standardization means converting a vector or column of an R data frame in a way such that the mean of the same becomes 0 and the standard deviation becomes 1, that is it should be converted to standard normal distribution. In R, it can be easily done with the help of scale function. Check out the below example to understand how it is done.ExampleConsider the below data frame:> set.seed(3665) > x1 x2 x3 x4 x5 x6 df dfOutputx1 x2 x3 x4 x5 x6 1 1.3958185 49.39843 128.5224 3 4.183664 2.33406246 2 1.0467979 48.90103 120.5796 7 3.526731 0.02043217 3 0.9190516 ...
Read MoreHow to find the mean of a square matrix elements by excluding diagonal elements in R?
There are many ways to find the mean of a matrix elements by excluding diagonal elements, this mean is actually the mean of lower triangular matrix and the upper triangular matrix. We can simply use mean function by creating a vector of lower and upper triangular matrix as shown in the below examples.Example1> M1 M1Output [, 1] [, 2] [, 3] [, 4] [1, ] 1 6 3 6 [2, ] 8 5 3 4 [3, ] 5 4 4 6 [4, ] 5 5 3 4 [5, ...
Read MoreHow to find the group-wise correlation coefficient in R?
If we have two continuous and one categorical column in an R data frame then we can find the correlation coefficient between continuous values for the categories in the categorical column. For this purpose, we can use by function and pass the cor function with the spearman method as shown in the below examples.Example1Consider the below data frame:> x1 y1 z1 df1 df1Output x1 y1 z1 1 A 1.1155324 2 2 C 0.9801564 3 3 B 0.9116162 1 4 A 0.8406772 3 5 C 0.8009355 2 6 A 0.9331637 2 7 B 1.0642089 1 ...
Read MoreHow to find the mean of row values in an R data frame using dplyr?
The mean of row values can be found by using rowwise function of dplyr package along with the mutate function to add the new column of means in the data frame. The rowwise function actually helps R to read the values in the data frame rowwise and then we can use mean function to find the means as shown in the below examples.Example1Consider the below data frame:> x1 x2 df1 df1Output x1 x2 1 0 8 2 2 3 3 2 5 4 0 5 5 3 2 6 0 10 7 3 5 8 1 7 9 0 4 ...
Read MoreHow to find the correlation coefficient between two data frames in R?
If two data frames in R have equal number of columns then we can find the correlation coefficient among the columns of these data frames which will be the correlation matrix. For example, if we have a data frame df1 that contains column x and y and another data frame df2 that contains column a and b then the correlation coefficient between df1 and df2 can be found by cor(df1, df2).Example1Consider the below data frame:> x1 x2 df1 df1Output x1 x2 1 39.56630 38.25632 2 39.43689 44.14647 3 40.80479 37.43309 4 ...
Read MoreHow to convert a named vector to a list in R?
A named vector cannot be directly converted to a list because we would need to un-name the vector names and convert those names to names of the list elements. This can be done by using lapply function function. For example, suppose we have a named vector x then it can be converted to a list by using the command x x1 names(x1) x1OutputA B C D E F G H I J K L M N O P Q R S T U V W X Y Z 1 2 3 4 5 6 7 8 9 10 11 12 ...
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