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Page 1231 of 2109
How to create a sequence of dates by using starting date in R?
The best way to create a sequence of anything is creating it with the help of seq function and this also applies to sequences of dates. But in case of dates, we need to read the dates in date format so that R can understand the input type and create the appropriate vector. If we do not use the date format for the date value then it won’t make sense to R and it will result in error.Examplesx1
Read MoreHow to find different elements between two string vectors in R?
Just like numerical vectors, we can find the different elements between two string vectors if there exists any. For this purpose, we can use setdiff function. For example, if we have a vector V1 that contains a, b, c, d, e, f and the other vector V2 that contains a, e, h, k, l, p, r, u, v, w then the different elements between these two vectors can be found as setdiff(V1,V2).Examplex1
Read MoreHow to find the sum of corresponding elements in multiple vectors even if they contain NA's in R?
If we have multiple vectors then the sum of the corresponding elements can be found by using rowSums functions and the vectors can be combined by using cbind so that R can easily read the corresponding elements. But if there are NA values in one or more vectors then we also need to add na.rm=TRUE argument.Exampleset.seed(100) x1
Read MoreHow to find the difference between regression line and the points in R?
The difference between regression line and the points on the scatterplot are actually the residuals, thus we need to calculate the residual from the model object. This can be simply done by using residuals function. For example, if we create a linear model defined as Model between x and y then the residuals will be found as residuals(Model).Consider the below data frame −Exampleset.seed(999) x1
Read MoreHow to find the index of the last occurrence of repeated values in a vector in R?
Indexing helps us to understand the location of the value in the vector. If we have a vector that contains repeated values then we might want to figure out the last occurrence of the repeated value. For example, if we have a vector x that contains 1, 1, 2, 1, 2 then the last occurrence of repeated values will be 4 and 5 because the last 1 is at 4th position and 2 is at the 5th position. We can find this by using tapply function in R.Examplex1
Read MoreHow 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”)
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