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To find the mean squared error for linear model, we can use predicted values of the model and find the error from dependent variable then take its square and the mean of the whole output. For example, if we have a linear model called M for a data frame df then we can find the mean squared error using the command mean((df$y-predict(M))^2).Example1Consider the below data frame −x1
To remove rows from the data frame that duplicate values greater than a certain number of times, we can create a subset for rows having duplicate values less than the certain number of times. For this purpose, we first need to extract the rows and then subset the data frame with the particular column as shown in the below examples.Example1Consider the below data frame −> x1 x2 df1 df1Output x1 x2 1 0 0 2 0 0 3 1 0 4 0 1 5 0 0 6 1 1 7 0 1 8 1 1 9 1 2 10 0 ... Read More
To find the count of a particular character in a string vector we can use nchar function along with gsub. For example, if we have a vector called x that contains string such India, Russia, Indonesia then we can find the number of times character i occurred then we can use the command nchar(gsub("[^i]","",x)) and the output will be 1 1 1 because first I’s in India and Indonesia will not be considered as they are in uppercase.Example1x1
To change the code “Yes” to 1, we can use ifelse function and set the Yes to 1 and others to 0. For example, if we have a data frame called df that contains a character column x which has Yes and No values then we can convert those values to 1 and 0 using the command ifelse(df$x=="Yes",1,0).Example1Consider the below data frame −Agree
We know that a data frame can contain any type of columns such as numerical, character, logical, factor, etc. And if a data frame contains multiple type of columns then we might want to find the number of columns for each type or of one type say numerical. For this purpose, we can use select_if function of dplyr package along with the length function as shown in the below examples.Example1Consider the below data frame −> x1 x2 x3 x4 df1 df1Output x1 x2 x3 x4 1 a -0.18404831 0.1082741 2 2 b -0.28597330 ... Read More
ExamplesConsider n = 16(00010000)Now find x = n-1 => 15(00001111) => x & n => 0Approach to solve this problemStep 1 − Define a method, where n and is an argument, returns type is int.Step 2 − Perform x = n & n-1.Step 3 − If x is 0, then the given number is power of 2; else not.Examplepackage main import ( "fmt" "strconv" ) func CheckNumberPowerOfTwo(n int) int { return n & (n-1) } func main(){ var n = 16 fmt.Printf("Binary of %d is: %s.", n, strconv.FormatInt(int64(n), 2)) flag := CheckNumberPowerOfTwo(n) if ... Read More
To split string vector elements, we can use strsplit function. And if we want to extract the string elements after splitting then double and single square brackets will be used. The double square bracket will extract the string vector element and the single square will extract the element after splitting. Check out the examples to understand how it works.Example1> x1 x1Output[1] "Tutorialspoint is an E-learning platform" [2] "E-learning is important" [3] "It helps in learning and growing at a faster rate"Example> x1 x1Output[[1]] [1] "Tutorialspoint" "is" "an" "E-learning" [5] "platform" [[2]] [1] "E-learning" "is" "important" [[3]] [1] "It" ... Read More
Definition − Parity refers to the count of 1s. If count of 1s is even, then it’s even parity; and if the count of 1s is odd, then the parity is Odd.ExamplesConsider n = 20(00010100)Parity of the given number 20 is even.Approach to solve this problemStep 1 − Define a method, where n and is an argument, return type is int.Step 2 − Calculate the count of 1s in the given number’s bit.Examplepackage main import ( "fmt" "strconv" ) func FindParity(n int) bool { parity := false for n != 0 { if ... Read More
ExamplesConsider two numbers m = 65 => 01000001 and n = 80 => 01010000Number of bits flipped is 2.Approach to solve this problemStep 1 − Convert both numbers into bits.Step 2 − Count number of bits are flipped.Examplepackage main import ( "fmt" "strconv" ) func FindBits(x, y int) int{ n := x ^ y count := 0 for ;n!=0; count++{ n = n & (n-1) } return count } func main(){ x := 65 y := 80 fmt.Printf("Binary of %d is: %s.", x, strconv.FormatInt(int64(x), 2)) fmt.Printf("Binary ... Read More
The character values can be stored in uppercase, lowercase, or a mixture of the two. If we have values that are either in uppercase or the mixture of lower and upper then we can convert those character values to only lowercase by using tolower function. We simply need to pass the vector or column of the data frame inside the tolower function as shown in the below examples.Example1Consider the below data frame −> x1 y1 df1 df1Output x1 y1 1 C -0.1036851 2 C -0.6176530 3 B 0.5763786 4 A 0.1943794 5 C 1.1196470 6 ... Read More