how to count no.of vector values in range with R

 

Count number of vector values in range with R

 

To achieve this functionality we can follow the following approach.

Approach

·         Create vector

·         Set range

·         Iterate through the vector

·         Check for elements that are within the range

·         Add them

·         Display sum

Implementation using this approach is given below.

Example 1:

# declaring a integer point vector

vec <- c(1,12,3,14,-1,-3)

 # specifying the range to check the element in

min_range = -2

max_range = 8

 # computing the size of the vector

size = length(vec)

 # declaring sum =0 as the count of elements in range

sum = 0

 # looping over the vector elements

for(i in 1:size)

 {

     # check if elements lies in the range provided

  if(vec[i]>=min_range && vec[i]<=max_range)

     # incrementing count of sum if condition satisfied

  sum =sum+1

      }

 print ("Sum of elements in range : ")

print (sum)

 

Example 2:

# declaring a integer point vector

vec <- c(1,12,3,14,-1,-3,0.1)

 # specifying the range to check the element in

min_range = -2

max_range = 8

print ("Sum of elements in specified range : ")

 # and operator check if the element is less than

# max range and greater than min range

sum(vec>min_range & vec<max_range)

 

Example 3

# declaring a integer point vector

vec <- c(1,12,3,14,NA,-3,0.1)

 # specifying the range to check the element in

min_range = -2

max_range = 8

print ("Sum of elements in specified range without ignoring NA: ")

 # and operator check if the element is less than

# max range and greater than min range

sum(vec>min_range & vec<max_range)

 print ("Sum of elements in specified range ignoring NA: ")

sum(vec>min_range & vec<max_range,na.rm=TRUE)

 

Count the specific value in a given vector in R

For finding the frequency of a given value two approaches can be employed and both of them are discussed below.

Method 1: Naive method 

We can iterate over the vector in R using a for loop and then check if the element is equivalent to the given value. A counter is maintained, and it is increased by 1, each time the value matches. In case, the element is not present, counter returns a value 0. The time complexity of the approach is O(n), where n is the size of the vector. 

Example:

 

# declaring a vector

vec = c(1,2,3,4,2,1,4,6)

  # printing original vector

print("Original Vectors:")

print(vec)

  # declaring count = 0 

count = 0

  # given value

x = 4

  # looping over vector values

for( i in vec){

        # check if the value is equal to x

    if(vec[i]==x){

                # increment counter by 1 

        count= count + 1

    }

}

  print("Count given value in above vector:")

  # check which values are equal to the given 

# value and calculate sum of it

print (count)

 

Method 2: Using sum() method in R

The sum() method can be used to calculate the summation of the values appearing in the function argument. Here, we specify a logical expression as an argument of the sum() function which calculates the sum of values which are equivalent to the specified value. In case the value is not present, the sum method returns 0 as an output. The time complexity of the approach is O(n), where n is the size of the vector. 

Syntax:

sum(vec == given_val)  

where, vec is the vector and given_val is the given value to check the presence for in the vector. 

Example:

# declaring a vector

vec = c("a","g","a","y","s","a","abcs")

  # printing original vector

print("Original Vectors:")

print(vec)

  print("Count given value in above vector:")

  # check which values are equal to the given 

# value and calculate sum of it

print(sum(vec=="a"))

 

 

Comments

Post a Comment

Popular posts from this blog

How to create Animated 3d chart with R.

  The rgl package is the best option to build 3d charts in R. Please see this post for an introduction to 3d scatterplots using it. It also provides the plot3d() and play3d() functions that allow to animate the 3d chart, and eventually to export the result at a .gif format. Here is an application to the famous iris dataset, with a nice animated 3d scatterplot chart. Arguments x, y, z vectors of points to be plotted. Any reasonable way of defining the coordinates is acceptable. See the function  xyz.coords  for details. xlab, ylab, zlab labels for the coordinates. type For the default method, a single character indicating the type of item to plot. Supported types are: 'p' for points, 's' for spheres, 'l' for lines, 'h' for line segments from z = 0, and 'n' for nothing. For the mesh3d method, one of 'shade', 'wire', or 'dots'. Partial matching is used. col the color to be used for plotted...
Read more

Linux/Unix Commands frequently used

  Linux/Unix Commands ls  --- lists your files ls -l  --- lists your files in 'long format', which contains lots of useful information, e.g. the exact size of the file, who owns the file and who has the right to look at it, and when it was last modified. ls -a  --- lists all files, including the ones whose filenames begin in a dot, which you do not always want to see. There are many more options, for example to list files by size, by date, recursively etc. more  filename  --- shows the first part of a file, just as much as will fit on one screen. Just hit the space bar to see more or  q  to quit. You can use  / pattern  to search for a pattern. gzip  filename  --- compresses files, so that they take up much less space. Usually text files compress to about half their original size, but it depends very much on the size of the file and the nature of the co...
Read more

R Programming Introduction

R Download Link- https://cran.r-project.org/bin/windows/base/old/3.4.0/ R Studio Download link- https://www.rstudio.com/products/rstudio/download/  R is a programming language and software environment for statistical analysis, graphics representation and reporting. R was created by Ross Ihaka and Robert Gentleman at the University of Auckland, New Zealand, and is currently developed by the R Development Core Team. The core of R is an interpreted computer language which allows branching and looping as well as modular programming using functions. R allows integration with the procedures written in the C, C++, .Net, Python or FORTRAN languages for efficiency. R is freely available under the GNU General Public License, and pre-compiled binary versions are provided for various operating systems like Linux, Windows and Mac. R is free software distributed under a GNU-style copy left, and an official part of the GNU project called  GNU S . Evolution of R R was initially writ...
Read more