CSV Files and Their Operations in R Programming Language: Methods and Examples
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Table of Content:
- Getting and Setting the Working Directory
- Input as CSV File
- Reading a CSV File
- Analyzing the CSV File
- Get the maximum salary
- Get the details of the person with max salary
- Get all the people working in IT department
- Get the persons in IT department whose salary is greater than 25000
- Get the people who joined on or after 2013
- Writing into a CSV File
- All code in one place
- Stay Ahead of the Curve! Check out these trending topics and sharpen your skills.
Getting and Setting the Working Directory
You can check which directory the R workspace is pointing to using the getwd() function. You can also set a new working directory using setwd()function.
<span class="pln"> </span><span class="com"># Get and print current working directory.</span><span class="pln"> </span><span class="kwd">print</span><span class="pun">(</span><span class="pln">getwd</span><span class="pun">())</span><span class="pln"> </span><span class="com"># Set current working directory.</span><span class="pln"> setwd</span><span class="pun">(</span><span class="str">"E:/R-Programming-Script-files"</span><span class="pun">)</span><span class="pln"> </span><span class="com"># Get and print current working directory.</span><span class="pln"> </span><span class="kwd">print</span><span class="pun">(</span><span class="pln">getwd</span><span class="pun">())</span><span class="pln"> </span>
When we execute the above code, it produces the following result ?
<span class="pln"> </span><span class="pun">[</span><span class="lit">1</span><span class="pun">]</span><span class="pln"> </span><span class="str">"C:/Users/Hello World/Documents"</span><span class="pln"> </span><span class="pun">[</span><span class="lit">1</span><span class="pun">]</span><span class="pln"> </span><span class="str">"E:/R-Programming-Script-files"</span><span class="pln"> </span>
This result depends on your OS and your current directory where you are working.
Input as CSV File
The csv file is a text file in which the values in the columns are separated by a comma. Let's consider the following data present in the file named inputData.csv.
You can create this file using windows notepad by copying and pasting this data. Save the file as inputData.csv using the save As All files(*.*) option in notepad.
<span class="pln"> id</span><span class="pun">,</span><span class="typ">Name</span><span class="pun">,</span><span class="pln">salary</span><span class="pun">,</span><span class="typ">Job_date</span><span class="pun">,</span><span class="pln">dept </span><span class="lit">1</span><span class="pun">,</span><span class="typ">Rumman</span><span class="pun">,</span><span class="lit">12623.3</span><span class="pun">,</span><span class="lit">01</span><span class="pun">-</span><span class="lit">01</span><span class="pun">-</span><span class="lit">2012</span><span class="pun">,</span><span class="pln">IT </span><span class="lit">2</span><span class="pun">,</span><span class="typ">Jaman</span><span class="pun">,</span><span class="lit">32515.2</span><span class="pun">,</span><span class="lit">23</span><span class="pun">-</span><span class="lit">09</span><span class="pun">-</span><span class="lit">2013</span><span class="pun">,</span><span class="typ">Operations</span><span class="pln"> </span><span class="lit">3</span><span class="pun">,</span><span class="typ">Inza</span><span class="pun">,</span><span class="lit">342611</span><span class="pun">,</span><span class="lit">15</span><span class="pun">-</span><span class="lit">11</span><span class="pun">-</span><span class="lit">2014</span><span class="pun">,</span><span class="pln">IT </span><span class="lit">4</span><span class="pun">,</span><span class="typ">Azam</span><span class="pun">,</span><span class="lit">232729</span><span class="pun">,</span><span class="lit">11</span><span class="pun">-</span><span class="lit">05</span><span class="pun">-</span><span class="lit">2014</span><span class="pun">,</span><span class="pln">HR </span><span class="lit">5</span><span class="pun">,</span><span class="typ">Sabir</span><span class="pun">,</span><span class="lit">45843.25</span><span class="pun">,</span><span class="lit">27</span><span class="pun">-</span><span class="lit">03</span><span class="pun">-</span><span class="lit">2015</span><span class="pun">,</span><span class="typ">Finance</span><span class="pln"> </span><span class="lit">6</span><span class="pun">,</span><span class="typ">Jakir</span><span class="pun">,</span><span class="lit">322578</span><span class="pun">,</span><span class="lit">21</span><span class="pun">-</span><span class="lit">05</span><span class="pun">-</span><span class="lit">2013</span><span class="pun">,</span><span class="pln">IT </span><span class="lit">7</span><span class="pun">,</span><span class="typ">Sourav</span><span class="pun">,</span><span class="lit">221632.8</span><span class="pun">,</span><span class="lit">30</span><span class="pun">-</span><span class="lit">07</span><span class="pun">-</span><span class="lit">2013</span><span class="pun">,</span><span class="typ">Operations</span><span class="pln"> </span><span class="lit">8</span><span class="pun">,</span><span class="typ">Ramu</span><span class="pun">,</span><span class="lit">22722.5</span><span class="pun">,</span><span class="lit">17</span><span class="pun">-</span><span class="lit">06</span><span class="pun">-</span><span class="lit">2014</span><span class="pun">,</span><span class="typ">Finance</span><span class="pln"> </span>
Reading a CSV File
Following is a simple example of read.csv() function to read a CSV file available in your current working directory −
<span class="pln"> data </span><span class="pun"><-</span><span class="pln"> read</span><span class="pun">.</span><span class="pln">csv</span><span class="pun">(</span><span class="str">"inputData.csv"</span><span class="pun">)</span><span class="pln"> </span><span class="kwd">print</span><span class="pun">(</span><span class="pln">data</span><span class="pun">)</span><span class="pln"> </span>
When we execute the above code, it produces the following result ?
<span class="pln"> id </span><span class="typ">Name</span><span class="pln"> salary </span><span class="typ">Job_date</span><span class="pln"> dept </span><span class="lit">1</span><span class="pln"> </span><span class="lit">1</span><span class="pln"> </span><span class="typ">Rumman</span><span class="pln"> </span><span class="lit">12623.30</span><span class="pln"> </span><span class="lit">01</span><span class="pun">-</span><span class="lit">01</span><span class="pun">-</span><span class="lit">2012</span><span class="pln"> IT </span><span class="lit">2</span><span class="pln"> </span><span class="lit">2</span><span class="pln"> </span><span class="typ">Jaman</span><span class="pln"> </span><span class="lit">32515.20</span><span class="pln"> </span><span class="lit">23</span><span class="pun">-</span><span class="lit">09</span><span class="pun">-</span><span class="lit">2013</span><span class="pln"> </span><span class="typ">Operations</span><span class="pln"> </span><span class="lit">3</span><span class="pln"> </span><span class="lit">3</span><span class="pln"> </span><span class="typ">Inza</span><span class="pln"> </span><span class="lit">342611.00</span><span class="pln"> </span><span class="lit">15</span><span class="pun">-</span><span class="lit">11</span><span class="pun">-</span><span class="lit">2014</span><span class="pln"> IT </span><span class="lit">4</span><span class="pln"> </span><span class="lit">4</span><span class="pln"> </span><span class="typ">Azam</span><span class="pln"> </span><span class="lit">232729.00</span><span class="pln"> </span><span class="lit">11</span><span class="pun">-</span><span class="lit">05</span><span class="pun">-</span><span class="lit">2014</span><span class="pln"> HR </span><span class="lit">5</span><span class="pln"> </span><span class="lit">5</span><span class="pln"> </span><span class="typ">Sabir</span><span class="pln"> </span><span class="lit">45843.25</span><span class="pln"> </span><span class="lit">27</span><span class="pun">-</span><span class="lit">03</span><span class="pun">-</span><span class="lit">2015</span><span class="pln"> </span><span class="typ">Finance</span><span class="pln"> </span><span class="lit">6</span><span class="pln"> </span><span class="lit">6</span><span class="pln"> </span><span class="typ">Jakir</span><span class="pln"> </span><span class="lit">322578.00</span><span class="pln"> </span><span class="lit">21</span><span class="pun">-</span><span class="lit">05</span><span class="pun">-</span><span class="lit">2013</span><span class="pln"> IT </span><span class="lit">7</span><span class="pln"> </span><span class="lit">7</span><span class="pln"> </span><span class="typ">Sourav</span><span class="pln"> </span><span class="lit">221632.80</span><span class="pln"> </span><span class="lit">30</span><span class="pun">-</span><span class="lit">07</span><span class="pun">-</span><span class="lit">2013</span><span class="pln"> </span><span class="typ">Operations</span><span class="pln"> </span><span class="lit">8</span><span class="pln"> </span><span class="lit">8</span><span class="pln"> </span><span class="typ">Ramu</span><span class="pln"> </span><span class="lit">22722.50</span><span class="pln"> </span><span class="lit">17</span><span class="pun">-</span><span class="lit">06</span><span class="pun">-</span><span class="lit">2014</span><span class="pln"> </span><span class="typ">Finance</span><span class="pln"> </span>
Analyzing the CSV File
By default the read.csv() function gives the output as a data frame. This can be easily checked as follows. Also we can check the number of columns and rows.
<span class="pln"> data </span><span class="pun"><-</span><span class="pln"> read</span><span class="pun">.</span><span class="pln">csv</span><span class="pun">(</span><span class="str">"inputData.csv"</span><span class="pun">)</span><span class="pln"> </span><span class="kwd">print</span><span class="pun">(</span><span class="kwd">is</span><span class="pun">.</span><span class="pln">data</span><span class="pun">.</span><span class="pln">frame</span><span class="pun">(</span><span class="pln">data</span><span class="pun">))</span><span class="pln"> </span><span class="kwd">print</span><span class="pun">(</span><span class="pln">ncol</span><span class="pun">(</span><span class="pln">data</span><span class="pun">))</span><span class="pln"> </span><span class="kwd">print</span><span class="pun">(</span><span class="pln">nrow</span><span class="pun">(</span><span class="pln">data</span><span class="pun">))</span><span class="pln"> </span>
When we execute the above code, it produces the following result ?
<span class="pln"> </span><span class="pun">></span><span class="pln"> data </span><span class="pun"><-</span><span class="pln"> read</span><span class="pun">.</span><span class="pln">csv</span><span class="pun">(</span><span class="str">"inputData.csv"</span><span class="pun">)</span><span class="pln"> </span><span class="pun">></span><span class="pln"> </span><span class="kwd">print</span><span class="pun">(</span><span class="kwd">is</span><span class="pun">.</span><span class="pln">data</span><span class="pun">.</span><span class="pln">frame</span><span class="pun">(</span><span class="pln">data</span><span class="pun">))</span><span class="pln"> </span><span class="pun">[</span><span class="lit">1</span><span class="pun">]</span><span class="pln"> TRUE </span><span class="pun">></span><span class="pln"> </span><span class="kwd">print</span><span class="pun">(</span><span class="pln">ncol</span><span class="pun">(</span><span class="pln">data</span><span class="pun">))</span><span class="pln"> </span><span class="pun">[</span><span class="lit">1</span><span class="pun">]</span><span class="pln"> </span><span class="lit">5</span><span class="pln"> </span><span class="pun">></span><span class="pln"> </span><span class="kwd">print</span><span class="pun">(</span><span class="pln">nrow</span><span class="pun">(</span><span class="pln">data</span><span class="pun">))</span><span class="pln"> </span><span class="pun">[</span><span class="lit">1</span><span class="pun">]</span><span class="pln"> </span><span class="lit">8</span><span class="pln"> </span>
Once we read data in a data frame, we can apply all the functions applicable to data frames as explained in subsequent section.
Get the maximum salary
<span class="pln"> </span><span class="com"># Create a data frame.</span><span class="pln"> data </span><span class="pun"><-</span><span class="pln"> read</span><span class="pun">.</span><span class="pln">csv</span><span class="pun">(</span><span class="str">"inputData.csv"</span><span class="pun">)</span><span class="pln"> </span><span class="com"># Get the max salary from data frame.</span><span class="pln"> sal </span><span class="pun"><-</span><span class="pln"> max</span><span class="pun">(</span><span class="pln">data$salary</span><span class="pun">)</span><span class="pln"> </span><span class="kwd">print</span><span class="pun">(</span><span class="pln">sal</span><span class="pun">)</span><span class="pln"> </span>
When we execute the above code, it produces the following result ?
<span class="pln"> </span><span class="pun">[</span><span class="lit">1</span><span class="pun">]</span><span class="pln"> </span><span class="lit">342611</span><span class="pln"> </span>
Get the details of the person with max salary
We can fetch rows meeting specific filter criteria similar to a SQL where clause.
<span class="pln"> </span><span class="com"># Create a data frame.</span><span class="pln"> data </span><span class="pun"><-</span><span class="pln"> read</span><span class="pun">.</span><span class="pln">csv</span><span class="pun">(</span><span class="str">"inputData.csv"</span><span class="pun">)</span><span class="pln"> </span><span class="com"># Get the max salary from data frame.</span><span class="pln"> sal </span><span class="pun"><-</span><span class="pln"> max</span><span class="pun">(</span><span class="pln">data$salary</span><span class="pun">)</span><span class="pln"> </span><span class="com"># Get the person detail having max salary.</span><span class="pln"> retval </span><span class="pun"><-</span><span class="pln"> subset</span><span class="pun">(</span><span class="pln">data</span><span class="pun">,</span><span class="pln"> salary </span><span class="pun">==</span><span class="pln"> max</span><span class="pun">(</span><span class="pln">salary</span><span class="pun">))</span><span class="pln"> </span><span class="kwd">print</span><span class="pun">(</span><span class="pln">retval</span><span class="pun">)</span><span class="pln"> </span>
When we execute the above code, it produces the following result ?
<span class="pln"> id </span><span class="typ">Name</span><span class="pln"> salary </span><span class="typ">Job_date</span><span class="pln"> dept </span><span class="lit">3</span><span class="pln"> </span><span class="lit">3</span><span class="pln"> </span><span class="typ">Inza</span><span class="pln"> </span><span class="lit">342611</span><span class="pln"> </span><span class="lit">15</span><span class="pun">-</span><span class="lit">11</span><span class="pun">-</span><span class="lit">2014</span><span class="pln"> IT </span>
Get all the people working in IT department
<span class="pln"> </span><span class="com"># Create a data frame.</span><span class="pln"> data </span><span class="pun"><-</span><span class="pln"> read</span><span class="pun">.</span><span class="pln">csv</span><span class="pun">(</span><span class="str">"inputData.csv"</span><span class="pun">)</span><span class="pln"> retval </span><span class="pun"><-</span><span class="pln"> subset</span><span class="pun">(</span><span class="pln"> data</span><span class="pun">,</span><span class="pln"> dept </span><span class="pun">==</span><span class="pln"> </span><span class="str">"IT"</span><span class="pun">)</span><span class="pln"> </span><span class="kwd">print</span><span class="pun">(</span><span class="pln">retval</span><span class="pun">)</span><span class="pln"> </span>
When we execute the above code, it produces the following result ?
<span class="pln"> id </span><span class="typ">Name</span><span class="pln"> salary </span><span class="typ">Job_date</span><span class="pln"> dept </span><span class="lit">1</span><span class="pln"> </span><span class="lit">1</span><span class="pln"> </span><span class="typ">Rumman</span><span class="pln"> </span><span class="lit">12623.3</span><span class="pln"> </span><span class="lit">01</span><span class="pun">-</span><span class="lit">01</span><span class="pun">-</span><span class="lit">2012</span><span class="pln"> IT </span><span class="lit">3</span><span class="pln"> </span><span class="lit">3</span><span class="pln"> </span><span class="typ">Inza</span><span class="pln"> </span><span class="lit">342611.0</span><span class="pln"> </span><span class="lit">15</span><span class="pun">-</span><span class="lit">11</span><span class="pun">-</span><span class="lit">2014</span><span class="pln"> IT </span><span class="lit">6</span><span class="pln"> </span><span class="lit">6</span><span class="pln"> </span><span class="typ">Jakir</span><span class="pln"> </span><span class="lit">322578.0</span><span class="pln"> </span><span class="lit">21</span><span class="pun">-</span><span class="lit">05</span><span class="pun">-</span><span class="lit">2013</span><span class="pln"> IT </span>
Get the persons in IT department whose salary is greater than 25000
<span class="pln"> </span><span class="com"># Create a data frame.</span><span class="pln"> data </span><span class="pun"><-</span><span class="pln"> read</span><span class="pun">.</span><span class="pln">csv</span><span class="pun">(</span><span class="str">"inputData.csv"</span><span class="pun">)</span><span class="pln"> info </span><span class="pun"><-</span><span class="pln"> subset</span><span class="pun">(</span><span class="pln">data</span><span class="pun">,</span><span class="pln"> salary </span><span class="pun">></span><span class="pln"> </span><span class="lit">25000</span><span class="pln"> </span><span class="pun">&</span><span class="pln"> dept </span><span class="pun">==</span><span class="pln"> </span><span class="str">"IT"</span><span class="pun">)</span><span class="pln"> </span><span class="kwd">print</span><span class="pun">(</span><span class="pln">info</span><span class="pun">)</span><span class="pln"> </span>
When we execute the above code, it produces the following result ?
<span class="pln"> id </span><span class="typ">Name</span><span class="pln"> salary </span><span class="typ">Job_date</span><span class="pln"> dept </span><span class="lit">3</span><span class="pln"> </span><span class="lit">3</span><span class="pln"> </span><span class="typ">Inza</span><span class="pln"> </span><span class="lit">342611</span><span class="pln"> </span><span class="lit">15</span><span class="pun">-</span><span class="lit">11</span><span class="pun">-</span><span class="lit">2014</span><span class="pln"> IT </span><span class="lit">6</span><span class="pln"> </span><span class="lit">6</span><span class="pln"> </span><span class="typ">Jakir</span><span class="pln"> </span><span class="lit">322578</span><span class="pln"> </span><span class="lit">21</span><span class="pun">-</span><span class="lit">05</span><span class="pun">-</span><span class="lit">2013</span><span class="pln"> IT </span>
Get the people who joined on or after 2013
<span class="pln"> </span><span class="com"># Create a data frame.</span><span class="pln"> data </span><span class="pun"><-</span><span class="pln"> read</span><span class="pun">.</span><span class="pln">csv</span><span class="pun">(</span><span class="str">"inputData.csv"</span><span class="pun">)</span><span class="pln"> retval </span><span class="pun"><-</span><span class="pln"> subset</span><span class="pun">(</span><span class="pln">data</span><span class="pun">,</span><span class="pln"> </span><span class="kwd">as</span><span class="pun">.</span><span class="typ">Date</span><span class="pun">(</span><span class="typ">Job_date</span><span class="pun">)</span><span class="pln"> </span><span class="pun">></span><span class="pln"> </span><span class="kwd">as</span><span class="pun">.</span><span class="typ">Date</span><span class="pun">(</span><span class="str">"2013-01-01"</span><span class="pun">))</span><span class="pln"> </span><span class="kwd">print</span><span class="pun">(</span><span class="pln">retval</span><span class="pun">)</span><span class="pln"> </span>
When we execute the above code, it produces the following result ?
<span class="pln"> </span><span class="pun">[</span><span class="lit">1</span><span class="pun">]</span><span class="pln"> id </span><span class="typ">Name</span><span class="pln"> salary </span><span class="typ">Job_date</span><span class="pln"> dept </span><span class="pun"><</span><span class="lit">0</span><span class="pln"> rows</span><span class="pun">></span><span class="pln"> </span><span class="pun">(</span><span class="kwd">or</span><span class="pln"> </span><span class="lit">0</span><span class="pun">-</span><span class="pln">length row</span><span class="pun">.</span><span class="pln">names</span><span class="pun">)</span><span class="pln"> </span>
Writing into a CSV File
R can create csv file form existing data frame. The write.csv() function is used to create the csv file. This file gets created in the working directory.
<span class="pln"> </span><span class="com"># Create a data frame.</span><span class="pln"> data </span><span class="pun"><-</span><span class="pln"> read</span><span class="pun">.</span><span class="pln">csv</span><span class="pun">(</span><span class="str">"inputData.csv"</span><span class="pun">)</span><span class="pln"> retval </span><span class="pun"><-</span><span class="pln"> subset</span><span class="pun">(</span><span class="pln">data</span><span class="pun">,</span><span class="pln"> </span><span class="kwd">as</span><span class="pun">.</span><span class="typ">Date</span><span class="pun">(</span><span class="typ">Job_date</span><span class="pun">)</span><span class="pln"> </span><span class="pun">></span><span class="pln"> </span><span class="kwd">as</span><span class="pun">.</span><span class="typ">Date</span><span class="pun">(</span><span class="str">"01-01-2013"</span><span class="pun">))</span><span class="pln"> </span><span class="com"># Write filtered data into a new file.</span><span class="pln"> write</span><span class="pun">.</span><span class="pln">csv</span><span class="pun">(</span><span class="pln">retval</span><span class="pun">,</span><span class="str">"output.csv"</span><span class="pun">)</span><span class="pln"> newdata </span><span class="pun"><-</span><span class="pln"> read</span><span class="pun">.</span><span class="pln">csv</span><span class="pun">(</span><span class="str">"output.csv"</span><span class="pun">)</span><span class="pln"> </span><span class="kwd">print</span><span class="pun">(</span><span class="pln">newdata</span><span class="pun">)</span><span class="pln"> </span>
When we execute the above code, it produces the following result ?
<span class="pln"> X id </span><span class="typ">Name</span><span class="pln"> salary </span><span class="typ">Job_date</span><span class="pln"> dept </span><span class="lit">1</span><span class="pln"> </span><span class="lit">2</span><span class="pln"> </span><span class="lit">2</span><span class="pln"> </span><span class="typ">Jaman</span><span class="pln"> </span><span class="lit">32515.20</span><span class="pln"> </span><span class="lit">23</span><span class="pun">-</span><span class="lit">09</span><span class="pun">-</span><span class="lit">2013</span><span class="pln"> </span><span class="typ">Operations</span><span class="pln"> </span><span class="lit">2</span><span class="pln"> </span><span class="lit">3</span><span class="pln"> </span><span class="lit">3</span><span class="pln"> </span><span class="typ">Inza</span><span class="pln"> </span><span class="lit">342611.00</span><span class="pln"> </span><span class="lit">15</span><span class="pun">-</span><span class="lit">11</span><span class="pun">-</span><span class="lit">2014</span><span class="pln"> IT </span><span class="lit">3</span><span class="pln"> </span><span class="lit">4</span><span class="pln"> </span><span class="lit">4</span><span class="pln"> </span><span class="typ">Azam</span><span class="pln"> </span><span class="lit">232729.00</span><span class="pln"> </span><span class="lit">11</span><span class="pun">-</span><span class="lit">05</span><span class="pun">-</span><span class="lit">2014</span><span class="pln"> HR </span><span class="lit">4</span><span class="pln"> </span><span class="lit">5</span><span class="pln"> </span><span class="lit">5</span><span class="pln"> </span><span class="typ">Sabir</span><span class="pln"> </span><span class="lit">45843.25</span><span class="pln"> </span><span class="lit">27</span><span class="pun">-</span><span class="lit">03</span><span class="pun">-</span><span class="lit">2015</span><span class="pln"> </span><span class="typ">Finance</span><span class="pln"> </span><span class="lit">5</span><span class="pln"> </span><span class="lit">6</span><span class="pln"> </span><span class="lit">6</span><span class="pln"> </span><span class="typ">Jakir</span><span class="pln"> </span><span class="lit">322578.00</span><span class="pln"> </span><span class="lit">21</span><span class="pun">-</span><span class="lit">05</span><span class="pun">-</span><span class="lit">2013</span><span class="pln"> IT </span><span class="lit">6</span><span class="pln"> </span><span class="lit">7</span><span class="pln"> </span><span class="lit">7</span><span class="pln"> </span><span class="typ">Sourav</span><span class="pln"> </span><span class="lit">221632.80</span><span class="pln"> </span><span class="lit">30</span><span class="pun">-</span><span class="lit">07</span><span class="pun">-</span><span class="lit">2013</span><span class="pln"> </span><span class="typ">Operations</span><span class="pln"> </span><span class="lit">7</span><span class="pln"> </span><span class="lit">8</span><span class="pln"> </span><span class="lit">8</span><span class="pln"> </span><span class="typ">Ramu</span><span class="pln"> </span><span class="lit">22722.50</span><span class="pln"> </span><span class="lit">17</span><span class="pun">-</span><span class="lit">06</span><span class="pun">-</span><span class="lit">2014</span><span class="pln"> </span><span class="typ">Finance</span><span class="pln"> </span>
Here the column X comes from the data set newper. This can be dropped using additional parameters while writing the file.
<span class="pln"> </span><span class="com"># Create a data frame.</span><span class="pln"> data </span><span class="pun"><-</span><span class="pln"> read</span><span class="pun">.</span><span class="pln">csv</span><span class="pun">(</span><span class="str">"inputData.csv"</span><span class="pun">)</span><span class="pln"> retval </span><span class="pun"><-</span><span class="pln"> subset</span><span class="pun">(</span><span class="pln">data</span><span class="pun">,</span><span class="pln"> </span><span class="kwd">as</span><span class="pun">.</span><span class="typ">Date</span><span class="pun">(</span><span class="typ">Job_date</span><span class="pun">)</span><span class="pln"> </span><span class="pun">></span><span class="pln"> </span><span class="kwd">as</span><span class="pun">.</span><span class="typ">Date</span><span class="pun">(</span><span class="str">"01-01-2014"</span><span class="pun">))</span><span class="pln"> </span><span class="com"># Write filtered data into a new file.</span><span class="pln"> write</span><span class="pun">.</span><span class="pln">csv</span><span class="pun">(</span><span class="pln">retval</span><span class="pun">,</span><span class="str">"output.csv"</span><span class="pun">,</span><span class="pln"> row</span><span class="pun">.</span><span class="pln">names </span><span class="pun">=</span><span class="pln"> FALSE</span><span class="pun">)</span><span class="pln"> newdata </span><span class="pun"><-</span><span class="pln"> read</span><span class="pun">.</span><span class="pln">csv</span><span class="pun">(</span><span class="str">"output.csv"</span><span class="pun">)</span><span class="pln"> </span><span class="kwd">print</span><span class="pun">(</span><span class="pln">newdata</span><span class="pun">)</span><span class="pln"> </span>
When we execute the above code, it produces the following result ?
<span class="pln"> id </span><span class="typ">Name</span><span class="pln"> salary </span><span class="typ">Job_date</span><span class="pln"> dept </span><span class="lit">1</span><span class="pln"> </span><span class="lit">2</span><span class="pln"> </span><span class="typ">Jaman</span><span class="pln"> </span><span class="lit">32515.20</span><span class="pln"> </span><span class="lit">23</span><span class="pun">-</span><span class="lit">09</span><span class="pun">-</span><span class="lit">2013</span><span class="pln"> </span><span class="typ">Operations</span><span class="pln"> </span><span class="lit">2</span><span class="pln"> </span><span class="lit">3</span><span class="pln"> </span><span class="typ">Inza</span><span class="pln"> </span><span class="lit">342611.00</span><span class="pln"> </span><span class="lit">15</span><span class="pun">-</span><span class="lit">11</span><span class="pun">-</span><span class="lit">2014</span><span class="pln"> IT </span><span class="lit">3</span><span class="pln"> </span><span class="lit">4</span><span class="pln"> </span><span class="typ">Azam</span><span class="pln"> </span><span class="lit">232729.00</span><span class="pln"> </span><span class="lit">11</span><span class="pun">-</span><span class="lit">05</span><span class="pun">-</span><span class="lit">2014</span><span class="pln"> HR </span><span class="lit">4</span><span class="pln"> </span><span class="lit">5</span><span class="pln"> </span><span class="typ">Sabir</span><span class="pln"> </span><span class="lit">45843.25</span><span class="pln"> </span><span class="lit">27</span><span class="pun">-</span><span class="lit">03</span><span class="pun">-</span><span class="lit">2015</span><span class="pln"> </span><span class="typ">Finance</span><span class="pln"> </span><span class="lit">5</span><span class="pln"> </span><span class="lit">6</span><span class="pln"> </span><span class="typ">Jakir</span><span class="pln"> </span><span class="lit">322578.00</span><span class="pln"> </span><span class="lit">21</span><span class="pun">-</span><span class="lit">05</span><span class="pun">-</span><span class="lit">2013</span><span class="pln"> IT </span><span class="lit">6</span><span class="pln"> </span><span class="lit">7</span><span class="pln"> </span><span class="typ">Sourav</span><span class="pln"> </span><span class="lit">221632.80</span><span class="pln"> </span><span class="lit">30</span><span class="pun">-</span><span class="lit">07</span><span class="pun">-</span><span class="lit">2013</span><span class="pln"> </span><span class="typ">Operations</span><span class="pln"> </span><span class="lit">7</span><span class="pln"> </span><span class="lit">8</span><span class="pln"> </span><span class="typ">Ramu</span><span class="pln"> </span><span class="lit">22722.50</span><span class="pln"> </span><span class="lit">17</span><span class="pun">-</span><span class="lit">06</span><span class="pun">-</span><span class="lit">2014</span><span class="pln"> </span><span class="typ">Finance</span><span class="pln"> </span>
All code in one place
<span class="pln"> </span><span class="com"># Get and print current working directory.</span><span class="pln"> </span><span class="kwd">print</span><span class="pun">(</span><span class="pln">getwd</span><span class="pun">())</span><span class="pln"> </span><span class="com"># Set current working directory.</span><span class="pln"> setwd</span><span class="pun">(</span><span class="str">"E:/R-Programming-Script-files"</span><span class="pun">)</span><span class="pln"> </span><span class="com"># Get and print current working directory.</span><span class="pln"> </span><span class="kwd">print</span><span class="pun">(</span><span class="pln">getwd</span><span class="pun">())</span><span class="pln"> data </span><span class="pun"><-</span><span class="pln"> read</span><span class="pun">.</span><span class="pln">csv</span><span class="pun">(</span><span class="str">"inputData.csv"</span><span class="pun">)</span><span class="pln"> </span><span class="kwd">print</span><span class="pun">(</span><span class="pln">data</span><span class="pun">)</span><span class="pln"> data </span><span class="pun"><-</span><span class="pln"> read</span><span class="pun">.</span><span class="pln">csv</span><span class="pun">(</span><span class="str">"inputData.csv"</span><span class="pun">)</span><span class="pln"> </span><span class="kwd">print</span><span class="pun">(</span><span class="kwd">is</span><span class="pun">.</span><span class="pln">data</span><span class="pun">.</span><span class="pln">frame</span><span class="pun">(</span><span class="pln">data</span><span class="pun">))</span><span class="pln"> </span><span class="kwd">print</span><span class="pun">(</span><span class="pln">ncol</span><span class="pun">(</span><span class="pln">data</span><span class="pun">))</span><span class="pln"> </span><span class="kwd">print</span><span class="pun">(</span><span class="pln">nrow</span><span class="pun">(</span><span class="pln">data</span><span class="pun">))</span><span class="pln"> </span><span class="com"># Create a data frame.</span><span class="pln"> data </span><span class="pun"><-</span><span class="pln"> read</span><span class="pun">.</span><span class="pln">csv</span><span class="pun">(</span><span class="str">"inputData.csv"</span><span class="pun">)</span><span class="pln"> </span><span class="com"># Get the max salary from data frame.</span><span class="pln"> sal </span><span class="pun"><-</span><span class="pln"> max</span><span class="pun">(</span><span class="pln">data$salary</span><span class="pun">)</span><span class="pln"> </span><span class="kwd">print</span><span class="pun">(</span><span class="pln">sal</span><span class="pun">)</span><span class="pln"> </span><span class="com"># Create a data frame.</span><span class="pln"> data </span><span class="pun"><-</span><span class="pln"> read</span><span class="pun">.</span><span class="pln">csv</span><span class="pun">(</span><span class="str">"inputData.csv"</span><span class="pun">)</span><span class="pln"> </span><span class="com"># Get the max salary from data frame.</span><span class="pln"> sal </span><span class="pun"><-</span><span class="pln"> max</span><span class="pun">(</span><span class="pln">data$salary</span><span class="pun">)</span><span class="pln"> </span><span class="com"># Get the person detail having max salary.</span><span class="pln"> retval </span><span class="pun"><-</span><span class="pln"> subset</span><span class="pun">(</span><span class="pln">data</span><span class="pun">,</span><span class="pln"> salary </span><span class="pun">==</span><span class="pln"> max</span><span class="pun">(</span><span class="pln">salary</span><span class="pun">))</span><span class="pln"> </span><span class="kwd">print</span><span class="pun">(</span><span class="pln">retval</span><span class="pun">)</span><span class="pln"> </span><span class="com"># Create a data frame.</span><span class="pln"> data </span><span class="pun"><-</span><span class="pln"> read</span><span class="pun">.</span><span class="pln">csv</span><span class="pun">(</span><span class="str">"inputData.csv"</span><span class="pun">)</span><span class="pln"> retval </span><span class="pun"><-</span><span class="pln"> subset</span><span class="pun">(</span><span class="pln"> data</span><span class="pun">,</span><span class="pln"> dept </span><span class="pun">==</span><span class="pln"> </span><span class="str">"IT"</span><span class="pun">)</span><span class="pln"> </span><span class="kwd">print</span><span class="pun">(</span><span class="pln">retval</span><span class="pun">)</span><span class="pln"> </span><span class="com"># Create a data frame.</span><span class="pln"> data </span><span class="pun"><-</span><span class="pln"> read</span><span class="pun">.</span><span class="pln">csv</span><span class="pun">(</span><span class="str">"inputData.csv"</span><span class="pun">)</span><span class="pln"> info </span><span class="pun"><-</span><span class="pln"> subset</span><span class="pun">(</span><span class="pln">data</span><span class="pun">,</span><span class="pln"> salary </span><span class="pun">></span><span class="pln"> </span><span class="lit">25000</span><span class="pln"> </span><span class="pun">&</span><span class="pln"> dept </span><span class="pun">==</span><span class="pln"> </span><span class="str">"IT"</span><span class="pun">)</span><span class="pln"> </span><span class="kwd">print</span><span class="pun">(</span><span class="pln">info</span><span class="pun">)</span><span class="pln"> </span><span class="com"># Create a data frame.</span><span class="pln"> data </span><span class="pun"><-</span><span class="pln"> read</span><span class="pun">.</span><span class="pln">csv</span><span class="pun">(</span><span class="str">"inputData.csv"</span><span class="pun">)</span><span class="pln"> retval </span><span class="pun"><-</span><span class="pln"> subset</span><span class="pun">(</span><span class="pln">data</span><span class="pun">,</span><span class="pln"> </span><span class="kwd">as</span><span class="pun">.</span><span class="typ">Date</span><span class="pun">(</span><span class="typ">Job_date</span><span class="pun">)</span><span class="pln"> </span><span class="pun">></span><span class="pln"> </span><span class="kwd">as</span><span class="pun">.</span><span class="typ">Date</span><span class="pun">(</span><span class="str">"2012-01-01"</span><span class="pun">))</span><span class="pln"> </span><span class="kwd">print</span><span class="pun">(</span><span class="pln">retval</span><span class="pun">)</span><span class="pln"> </span><span class="com"># Create a data frame.</span><span class="pln"> data </span><span class="pun"><-</span><span class="pln"> read</span><span class="pun">.</span><span class="pln">csv</span><span class="pun">(</span><span class="str">"inputData.csv"</span><span class="pun">)</span><span class="pln"> retval </span><span class="pun"><-</span><span class="pln"> subset</span><span class="pun">(</span><span class="pln">data</span><span class="pun">,</span><span class="pln"> </span><span class="kwd">as</span><span class="pun">.</span><span class="typ">Date</span><span class="pun">(</span><span class="typ">Job_date</span><span class="pun">)</span><span class="pln"> </span><span class="pun">></span><span class="pln"> </span><span class="kwd">as</span><span class="pun">.</span><span class="typ">Date</span><span class="pun">(</span><span class="str">"01-01-2013"</span><span class="pun">))</span><span class="pln"> </span><span class="com"># Write filtered data into a new file.</span><span class="pln"> write</span><span class="pun">.</span><span class="pln">csv</span><span class="pun">(</span><span class="pln">retval</span><span class="pun">,</span><span class="str">"output.csv"</span><span class="pun">)</span><span class="pln"> newdata </span><span class="pun"><-</span><span class="pln"> read</span><span class="pun">.</span><span class="pln">csv</span><span class="pun">(</span><span class="str">"output.csv"</span><span class="pun">)</span><span class="pln"> </span><span class="kwd">print</span><span class="pun">(</span><span class="pln">newdata</span><span class="pun">)</span><span class="pln"> </span><span class="com"># Create a data frame.</span><span class="pln"> data </span><span class="pun"><-</span><span class="pln"> read</span><span class="pun">.</span><span class="pln">csv</span><span class="pun">(</span><span class="str">"inputData.csv"</span><span class="pun">)</span><span class="pln"> retval </span><span class="pun"><-</span><span class="pln"> subset</span><span class="pun">(</span><span class="pln">data</span><span class="pun">,</span><span class="pln"> </span><span class="kwd">as</span><span class="pun">.</span><span class="typ">Date</span><span class="pun">(</span><span class="typ">Job_date</span><span class="pun">)</span><span class="pln"> </span><span class="pun">></span><span class="pln"> </span><span class="kwd">as</span><span class="pun">.</span><span class="typ">Date</span><span class="pun">(</span><span class="str">"01-01-2014"</span><span class="pun">))</span><span class="pln"> </span><span class="com"># Write filtered data into a new file.</span><span class="pln"> write</span><span class="pun">.</span><span class="pln">csv</span><span class="pun">(</span><span class="pln">retval</span><span class="pun">,</span><span class="str">"output.csv"</span><span class="pun">,</span><span class="pln"> row</span><span class="pun">.</span><span class="pln">names </span><span class="pun">=</span><span class="pln"> FALSE</span><span class="pun">)</span><span class="pln"> newdata </span><span class="pun"><-</span><span class="pln"> read</span><span class="pun">.</span><span class="pln">csv</span><span class="pun">(</span><span class="str">"output.csv"</span><span class="pun">)</span><span class="pln"> </span><span class="kwd">print</span><span class="pun">(</span><span class="pln">newdata</span><span class="pun">)</span><span class="pln"> </span>
No Questions Data Available.
No Program Data.