Server Side Programming Articles - Page 1534 of 2650

Dealing with NA values is one of the boring and almost day to day task for an analyst and hence we need to replace it with the appropriate value. If in an R data frame, we have a Boolean column that represents TRUE and FALSE values, and we have only FALSE values then we might want to replace NA’s with TRUE. In this case, we can use single square bracket and is.na to set all NA’s to TRUE.Exampleset.seed(999) S.No.

Sometimes we have missing values that can be replaced with the values on the above row values, it often happens in situations when the data is recorded manually and the person responsible for it just mention the unique values because he or she understand the data characteristics. But if this data needs to be re-used by someone else then it does not make sense and we have to connect with the concerned person. If the concerned person tells us that the first value in each row can be filled for every NA in the same column then it can be ... Read More

The value of mean is an important characteristic of the data to be represented by a histogram, therefore, one might want to plot it with the histogram. If the histogram is created by using hist function then we can create a vertical line on the histogram with the help of abline function by defining mean of the data for vertical argument v.Exampleset.seed(101) x

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).Example Live Demox1

Finding the sum of consecutive value while considering the sum of two values each time means the sum of first two values, then the sum of second value and the third value, then the sum of third value and the fourth value, then the sum of fourth value and the fifth value, and so on. For this purpose, we can use rollapply function from zoo package.Loading zoo packageibrary(zoo)Example Live Demox1

To create a horizontal bar chart using ggplot2 package, we need to use coord_flip() function along with the geom_bar and to add the labels geom_text function is used. These two functions of ggplot2 provides enough aesthetic characteristics to create the horizontal bar chart and put the labels at inside end of the bars.Example Live Demox

Suppose we have a number n, we have to find the length of the longest consecutive run of 1s in its binary representation.So, if the input is like n = 312, then the output will be 3, as 312 is 100111000 in binary and there are 3 consecutive 1s.To solve this, we will follow these steps −ret := 0, len := 0for initialize i := 0, when i < 32, update (increase i by 1), do:if n/2 is odd, then(increase len by 1)Otherwiselen := 0ret := maximum of ret and lenreturn retLet us see the following implementation to get better ... Read More

We can use permn function from combinat package to find the permutations but if we have repeated elements in the vector then the result will not have unique permutations, therefore, we need to use unique function along with the permn function. For example, if we have a vector 1, 2, 1 then the permutations will be (1 2 1), (1 1 2), (1 1 2), (1 2 1), (2 1 1), (2 1 1) and the unique permutations will be (1 2 1), (1 1 2), (2 1 1).Example Live Demox1

A legend helps us to differentiate between the type of values or any another division of values in a data set. These legends can be represented in many ways and two of these ways are straight lines and stars. To represent the legend in a plot created by using plot function with colored straight lines or stars, we need to correct lty and pch arguments.ExampleConsider the below vectors −set.seed(199) x

Suppose we have a matrix M where M[r][c] represents the height of that cell. If we are currently at top left corner and want to go to the bottom right corner. We can move to adjacent cells (up, down, left, right) only if that the height of that adjacent cell is less than or equal to the current cell's height. We can increase the height of any number of cells before we move, so we have to find the minimum total height that needs to be increased so that we can go to the bottom right cell.So, if the input ... Read More