Programming Articles - Page 1446 of 3363

A unique combination of vector elements can be found by using combn function with unique function and size argument will help us to identify the size of each of combination. For example, if we have a vector containing string values defined as x then the unique combinations of vector elements of size 2 can be created by using combn(unique(x),2).Example1 Live Demox1

The font size of the main title of boxplot can be changed by defining the font size value using par(cex.main=”size”), here size value can be changed based on our requirement. This needs to be done before creating the boxplot, otherwise, there will be no effect on the size of the main title.Example Live Demox

The maximum value is a part of summary statistics and we always need to understand the end limits of our data; therefore, it is highly required. If we have a data frame that contains numerical columns then the maximum value can be found by using max function and the data frame object name.Example1 Live DemoConsider the below data frame −set.seed(357) x1

There are situations when we might want to remove column names such as we want to manually replace the existing column names by new names or we simply don’t want to use them if we are very much familiar with the column characteristics. To remove the columns names we can simply set them to NULL as shown in the below examples.Example1Consider the below data frame − Live Demoset.seed(357) x1

When we have NA’s/missing values in an R vector then we want to replace those NA’s and for this purpose we might be needing the position of those values. These positions will be helpful especially in situations when we want to manually replace the missing values. The replacement can be done by using which function with is.na.Example1 Live Demox1

If the matrix is singular then it is not invertible and if it is non−singular then it is invertible. Therefore, we can check if a matrix is singular or not. We can use is.singular.matrix function of matrixcalc for this purpose. For example, if we have a matrix called M then to check whether it is invertible or not, we can use is.singular.matrix(M).Example1Loading matrixcalc package and creating a matrix −library(matrixcalc) M1

In data analysis, we sometimes deal with duplicated data or just the representation of the data with same name. One such situation is column names are same for two columns in a data.table object. For this purpose, we can make use of which function with the combination of duplicated function and set the output of that duplicate to NULL to remove the repeated column names.Example1Loading data.table package and creating a data.table object −library(data.table) x1

The Timsort is a stable sorting algorithm that uses the idea of merge sort and insertion sort. It can also be called as a hybrid algorithm of insertion and merge sort. It is widely used in Java, Python, C, and C++ inbuilt sort algorithms. The idea behind this algorithm is to sort small chunks using insertion sort and then merge all the big chunks using the merge function of the merge sort algorithm.WorkingIn this algorithm, the array is divided into small chunks. The chunks are known as RUN. Each RUN is taken and sorted using the insertion sort technique. After ... Read More

Delannoy Numbers − A Delannoy number D describes the number of paths from the southwest corner(0, 0) to northeast corner(a, b) in a rectangular grid using only allowed steps east ( →), northeast ( ↗ ) and north ( ↑ ).Thus, we can say that a recurrence relation is, D(a, b) = D(a-1, b) + D(a, b-1) + D(a-1, b-1) where D(0, 0)=1.For example, the Delannoy number D(3, 3) equals 63.Algorithm to find the Delannoy NumberTake two coordinates (a, b) as Input.An Integer function generateDelannoy(int a, int b) which takes coordinates ‘a’ and ‘b’ as input.In the base case, we ... Read More

Given an IP Address, the task is to validate this IP address and check whether it is IPv6 or not with the help of ReGex(Regular Expression). If the IP Address is valid then print “IPv6 Address” otherwise print “Not”.A valid IPv4 address is an IP in the form "XXXX:XXXX:XXXX:XXXX:XXXX:XXXX:XXXX:XXXX" where each Xi digit is a hexadecimal digit. For example, Input-1 −IP= “3001:0da8:82a3:0:0:8B2E:0270:7224”Output −“Not”Explanation − This is not a valid IPv6 address, return “Not”.Input-2 −IP= “2001:0db8:85a3:0000:0000:8a2e:0370:7334”Output −“IPv6”Explanation − This is a valid IPv6 Address, return “IPv6”.Approach to solve this problemTo check whether the given IP address is IPv6 or not, we ... Read More