Add a new column from an existing column with a calculation from the previous column

R Programming Language Data Frames in R Language (Article) Data Frames in R Language (Program)

278

---

Program:

<span class="com"># input code</span><span class="pln">

</span><span class="typ">Student</span><span class="pln"> </span><span class="pun">&lt;-</span><span class="pln"> data</span><span class="pun">.</span><span class="pln">frame</span><span class="pun">(</span><span class="pln">
</span><span class="typ">RollNo</span><span class="pln"> </span><span class="pun">=</span><span class="pln"> </span><span class="lit">1</span><span class="pun">:</span><span class="lit">10</span><span class="pun">,</span><span class="pln">  
</span><span class="typ">Marks</span><span class="pln"> </span><span class="pun">=</span><span class="pln"> c</span><span class="pun">(</span><span class="lit">10</span><span class="pun">,</span><span class="pln"> </span><span class="lit">20</span><span class="pun">,</span><span class="pln"> </span><span class="lit">30</span><span class="pun">,</span><span class="pln"> </span><span class="lit">40</span><span class="pun">,</span><span class="pln"> </span><span class="lit">50</span><span class="pun">,</span><span class="pln"> </span><span class="lit">60</span><span class="pun">,</span><span class="pln"> </span><span class="lit">70</span><span class="pun">,</span><span class="pln"> </span><span class="lit">80</span><span class="pun">,</span><span class="pln"> </span><span class="lit">90</span><span class="pun">,</span><span class="pln"> </span><span class="lit">95</span><span class="pun">),</span><span class="pln"> 
</span><span class="typ">PassOrFail</span><span class="pln"> </span><span class="pun">=</span><span class="pln"> c</span><span class="pun">(</span><span class="pln">F</span><span class="pun">,</span><span class="pln"> F</span><span class="pun">,</span><span class="pln"> F</span><span class="pun">,</span><span class="pln"> F</span><span class="pun">,</span><span class="pln"> F</span><span class="pun">,</span><span class="pln"> T</span><span class="pun">,</span><span class="pln"> T</span><span class="pun">,</span><span class="pln"> T</span><span class="pun">,</span><span class="pln"> T</span><span class="pun">,</span><span class="pln"> T</span><span class="pun">))</span><span class="pln">

</span><span class="com"># code for output</span><span class="pln">

</span><span class="pun">&gt;</span><span class="pln"> </span><span class="com"># add marks to each student and creating a new column</span><span class="pln">
</span><span class="pun">&gt;</span><span class="pln"> </span><span class="typ">Student$NewMarks</span><span class="pln"> </span><span class="pun">&lt;-</span><span class="pln"> </span><span class="typ">Student$Marks</span><span class="pln"> </span><span class="pun">+</span><span class="pln"> </span><span class="lit">5</span>

Output:

> str(Student)
'data.frame':	10 obs. of  5 variables:
 $ RollNo     : int  1 2 3 4 5 6 7 8 9 10
 $ Marks      : num  10 20 30 40 50 60 70 80 90 95
 $ PassOrFail : logi  TRUE TRUE TRUE TRUE TRUE TRUE ...
 $ StudentName: chr  "Rumman" "Inza" "Jaman" "Azam" ...
 $ NewMarks   : num  15 25 35 45 55 65 75 85 95 100

Explanation:

---

---