R language count rows of dataframe matching a criteria

Question

I have a dataframe population with Height and Weight

    Height    Weight
1   1.4349813 53.73766
2   1.6875582 61.83858
3   1.4952729 51.64203
etc....

How can I count how many of these people have a height higher than 1.70 and a weight higher than 60?

I tried nrow(which(population$Height > 1.70 && population$Weight > 60))

Answer 1

您可以按照以下步骤进行：

sum(population$Height > 1.70 & population$Weight > 60)

Answer 2

With base R:

nrow(population[population$Height > 1.70 & population$Weight > 60, ])

With dpylr:

library(dpylr)

population %>% filter(Height > 1.70 & Weight > 60) %>% nrow()