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R Programming Articles
Page 68 of 174
How to convert the repeated elements of strings in a vector to unique elements in R?
When we have repeated elements of strings and we want to use them as factor levels then it is okay but if we want to treat them individually then it is better to make each value a unique element. To do this, we can use make.unique function. For example, if we have a vector x that contains repeated string values then to make them unique, we can use make.unique(x).Examplex1
Read MoreHow to standardize matrix elements in R?
The standardization is the process of converting a value to another value so that the mean of the set of values from which the original value was taken becomes zero and the standard deviation becomes one. To standardize matrix elements, we can use data.Normalization function of clusterSim package but we need to make sure that we set the type argument to n1 because that corresponds to standardization with mean zero and standard deviation 1.Loading clusterSim package −library("clusterSim")ExampleM1
Read MoreHow to create a string vector with numbers at the end in R?
If we want to create a categorical vector with all unique values representing strings with numbers at the end then paste0 function can help us in the same. For example, if we want to create a vector for ID up to 10 as ID1, ID2, ID3, ID4, ID5, ID6, ID7, ID8, ID9, and ID10 then it can be done as paste0("ID",seq(1:10)).Examplex1
Read MoreHow to create a subset of matrix in R using greater than or less than a certain value of a column?
Subsetting can be required in many different ways, we can say that there might be infinite number of ways for subsetting as it depends on the objective of the bigger or smaller analysis. One such way is subsetting a matrix based on a certain value of column of the matrix. In R, we can easily do the same with the help of subset function as shown in below example.ExampleM3)Output [,1] [,2] [,3] [,4] [,5] [,6] [,7] [,8] [,9] [,10] [1,] 4 14 24 34 44 54 64 74 84 94 [2,] 5 15 25 35 45 55 65 75 85 95 [3,] 6 16 26 36 46 56 66 76 86 96 [4,] 7 17 27 37 47 57 67 77 87 97 [5,] 8 18 28 38 48 58 68 78 88 98 [6,] 9 19 29 39 49 59 69 79 89 99 [7,] 10 20 30 40 50 60 70 80 90 100Examplesubset(M,M[,1]75)Output[,1] [,2] [,3] [,4] [,5] [,6] [,7] [,8] [,9] [,10] [1,] 6 16 26 36 46 56 66 76 86 96 [2,] 7 17 27 37 47 57 67 77 87 97 [3,] 8 18 28 38 48 58 68 78 88 98 [4,] 9 19 29 39 49 59 69 79 89 99 [5,] 10 20 30 40 50 60 70 80 90 100Examplesubset(M,M[,9]>81)Output[,1] [,2] [,3] [,4] [,5] [,6] [,7] [,8] [,9] [,10] [1,] 2 12 22 32 42 52 62 72 82 92 [2,] 3 13 23 33 43 53 63 73 83 93 [3,] 4 14 24 34 44 54 64 74 84 94 [4,] 5 15 25 35 45 55 65 75 85 95 [5,] 6 16 26 36 46 56 66 76 86 96 [6,] 7 17 27 37 47 57 67 77 87 97 [7,] 8 18 28 38 48 58 68 78 88 98 [8,] 9 19 29 39 49 59 69 79 89 99 [9,] 10 20 30 40 50 60 70 80 90 100Examplesubset(M,M[,9]
Read MoreHow to change column names to capital letters from lower case or vice versa in R?
Mostly, we get data that contain column names in lowercase or just first letter is in upper case. If we want to convert those column names to all capital letter words or uppercase then toupper function can be used to the names of the columns. This can be done by using the below syntax −Syntaxnames(“data_frame_name”)
Read MoreHow to find the rank of a vector elements in R from largest to smallest?
To find the rank of a vector of elements we can use rank function directly but this will result in ranks from smallest to largest. For example, if we have a vector x that contains values 1, 2, 3 in this sequence then the rank function will return 1 2 3. But if we want to get ranks from largest to smallest then it would be 3 2 1 and it can be done in R as rank(-x).Examplex1
Read MoreHow to check whether a string is in lowercase or uppercase in R?
We can use str_detect function to check whether a single string or a vector of strings is in lowercase or uppercase. Along with str_detect function, we need to use either upper or lower to check whether the string is in lowercase or uppercase and the output will be returned in TRUE or FALSE form, if the string will be in lowercase and we pass lower with str_detect function then the output will be TRUE and vice-versa.Examplex1
Read MoreHow to remove the row names or column names from a matrix in R?
To remove the row names or column names from a matrix, we just need to set them to NULL, in this way all the names will be nullified. For example, if we have a matrix M that contain row names and column names then we can remove those names by using the command colnames(M)
Read MoreHow to create unordered triplets of a vector elements in R?
To create triplets of a vector elements, we can use combn function. For example, if we have a vector x that contain values 1, 2, 3, 4, 5 then the unordered triplets of x can be created by using combn(x,3). This will create a matrix where the elements of the vector x would not be arranged in a particular order.Examplex1
Read MoreHow to create a list of matrices in R?
To create a list of matrices, we simply need to find the matrix object inside list function. For example, if we have five matrix objects either of same or different dimensions defined as Matrix1, Matrix2, Matrix3, Matrix4, and Matrix5 then the list of these matrices can be created as −List_of_Matrix
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