Mehdi Farhangian - 2 months ago 17

R Question

I have the following dataset

`#df`

Factors Transactions

a,c 1

b 0

c 0

d,a 0

a 1

a 0

b 1

I'd like to know how many times we did

`#desired output`

Factors count

a 1

b 2

c 2

d 3

For instance, only one time we didn't had

`a`

There are many ways to know how many times we had each factor and we had transactions. For instance I tried this one:

`library(data.table)`

setDT(df)[, .(Factors = unlist(strsplit(as.character(Factors), ","))),

by = Transactions][,.(Transactions = sum(Transactions > 0)), by = Factors]

But I wish to count how many times we

Thanks in advance.

Answer

You can calculate the opposite, i.e, how many times the factor has a transaction and then the difference between the total transactions and transactions for each individual factor would be what you are looking for:

```
library(data.table)
total <- sum(df$Transactions > 0)
(setDT(df)[, .(Factors = unlist(strsplit(as.character(Factors), ","))), Transactions]
[, total - sum(Transactions > 0), Factors])
# Factors V1
#1: a 1
#2: c 2
#3: b 2
#4: d 3
```

Source (Stackoverflow)

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