I have a large data.table
that I want to generate a random number (using two columns) and perform a calculation. Then I want to perform this step 1,000 times. I am looking for a way to do this efficiently with out a loop.
Example data:
> dt <- data.table(Group=c(rep("A",3),rep("B",3)),
Year=rep(2020:2022,2),
N=c(300,350,400,123,175,156),
Count=c(25,30,35,3,6,8),
Pop=c(1234,1543,1754,2500,2600,2400))
> dt
Group Year N Count Pop
1: A 2020 300 25 1234
2: A 2021 350 30 1543
3: A 2022 400 35 1754
4: B 2020 123 3 2500
5: B 2021 175 6 2600
6: B 2022 156 8 2400
> dt[, rate := rpois(.N, lambda=Count)/Pop*100000]
> dt[, value := N*(rate/100000)]
> dt
Group Year N Count Pop rate value
1: A 2020 300 25 1234 1944.8947 5.8346840
2: A 2021 350 30 1543 2009.0732 7.0317563
3: A 2022 400 35 1754 1938.4265 7.7537058
4: B 2020 123 3 2500 120.0000 0.1476000
5: B 2021 175 6 2600 115.3846 0.2019231
6: B 2022 156 8 2400 416.6667 0.6500000
I want to be able to do this calculation for value
1,000 times, and keep all instances (with an indicator column for 1-1,000 indicating which run) without using a loop. Any suggestions?
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