10.20 Subset of Rows Within Groups
20200814 The dplyr::slice() command understands
groups and so the indicies supplied will apply to each group. To
select, for example, the second row of each group, simply supply
2 as the argument. Notice the rows selected are all on the
second of the month.
ds %>%
group_by(location) %>%
slice(2)## # A tibble: 49 × 24
## # Groups: location [49]
## date location min_temp max_temp rainfall evaporation sunshine
## <date> <chr> <dbl> <dbl> <dbl> <dbl> <dbl>
## 1 2008-07-02 Adelaide 12.7 15.8 0.8 1.4 7.8
## 2 2008-12-02 Albany 14.7 21 0 5.4 9.1
## 3 2008-12-02 Albury 7.4 25.1 0 4.8 8.5
## 4 2008-12-02 AliceSprings 21 39.1 1.2 9 12.2
## 5 2009-01-02 BadgerysCreek 14.7 26.1 0 4.8 8.5
## 6 2008-12-02 Ballarat 4.3 19.5 0.4 4.8 8.5
## 7 2008-12-02 Bendigo 6.2 23 0 8.8 8.5
## 8 2008-07-02 Brisbane 8.1 22.9 0 2 9.8
## 9 2008-12-02 Cairns 24.2 32.3 8.4 6.6 5.3
## 10 2007-11-02 Canberra 14 26.9 3.6 4.4 9.7
## # ℹ 39 more rows
## # ℹ 17 more variables: wind_gust_dir <ord>, wind_gust_speed <dbl>,
## # wind_dir_9am <ord>, wind_dir_3pm <ord>, wind_speed_9am <dbl>,
## # wind_speed_3pm <dbl>, humidity_9am <dbl>, humidity_3pm <int>,
## # pressure_9am <dbl>, pressure_3pm <dbl>, cloud_9am <int>, cloud_3pm <int>,
## # temp_9am <dbl>, temp_3pm <dbl>, rain_today <fct>, risk_mm <dbl>,
## # rain_tomorrow <fct>Your donation will support ongoing availability and give you access to the PDF version of this book. Desktop Survival Guides include Data Science, GNU/Linux, and MLHub. Books available on Amazon include Data Mining with Rattle and Essentials of Data Science. Popular open source software includes rattle, wajig, and mlhub. Hosted by Togaware, a pioneer of free and open source software since 1984. Copyright © 1995-2022 Graham.Williams@togaware.com Creative Commons Attribution-ShareAlike 4.0
