CODEWITHSUNDEEP
r
tassones
tassones

Reputation: 1692

Count number of values less than an increasing value

I have a data frame where I want to count the number of values less or equal to 30, then count the number of values less than or equal to 60, less than or equal to 90...etc. I can do this iteratively using the sum(dat$values <= 30) but I would like to automate this somehow.

Example

set.seed(917)
dat <- as.data.frame(sample(0:2100,100,replace = F))
colnames(dat)[1] <- "values"

sum(dat$values <= 30)
sum(dat$values <= 60)
sum(dat$values <= 90)
sum(dat$values <= 120)
sum(dat$values <= 150)

Output should look like

  BinWidth TotalValuesLessThan
1       30                   1
2       60                   1
3       90                   2
4      120                   3
5      150                   4

I would like to have the output iteratively go out to BinWidth = 2100 without needing to use sum(dat$values <= X) 70 times.

Upvotes: 1

Views: 67

Answers (2)

G. Grothendieck
G. Grothendieck

Reputation: 269764

We can use findInterval:

BinWidth <- seq(30, 150, 30)
data.frame(BinWidth, TotalLessThan = findInterval(BinWidth, sort(dat$values)))
##   BinWidth TotalLessThan
## 1       30             0
## 2       60             1
## 3       90             3
## 4      120             6
## 5      150             6

Upvotes: 0

caldwellst
caldwellst

Reputation: 5956

Just create your bins and apply along them.

BinWidth <- seq(30, 2100, by = 30)
TotalValueLessThan <- sapply(BinWidth, \(x) sum(dat$values <= x))

head(data.frame(BinWidth, TotalValueLessThan))
#>   BinWidth TotalValueLessThan
#> 1       30                  0
#> 2       60                  1
#> 3       90                  3
#> 4      120                  6
#> 5      150                  6
#> 6      180                 10

Change \(x) to function(x) if you are using R < 4.1.

Upvotes: 1

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