Counting the quantity of the items from data.frame

Question

I have a data.frame with 2 columns and it looks like this

Now, I have form a table which contains the quantity of the items

Such as,

item   Quantity
   A          7
   B          2
   C          5

Please help with this!

Simple Google search would have given the answer. – dikesh Feb 04 '16 at 04:42 — dikesh, Feb 04 '16 at 04:42
I just want to add the values of C2 with same value of C1 – Sandesh Feb 04 '16 at 04:42 — Sandesh, Feb 04 '16 at 04:42

Ronak Shah · Accepted Answer · 2016-02-04T04:43:58.167

0

I think you just need aggregate

aggregate(df$c2, list(df$c1), sum)

#  Group.1 x
#1       A 7
#2       B 2
#3       C 5

Or as the @thelatemail suggested to preserve the column names you can use

aggregate(c2 ~ c1, data=df, sum)

#c1 c2
#1  A  7
#2  B  2
#3  C  5

edited Feb 04 '16 at 04:43

answered Feb 04 '16 at 04:42

Ronak Shah

1

Or `aggregate(c2 ~ c1, data=df, sum)` or `aggregate(df["c2"], df["c1"], sum)` – thelatemail Feb 04 '16 at 04:43

1 Answers1