3.16 Pipes: Tee Pipe Intermediate Results
20220511 The tee-pipe comes in handy with
base::assign()ing intermediate results into a variable without
breaking the main flow of the pipeline. In the following example the
variable tmp
has an intermediate value assigned to it within the
base::globalenv() so that we can access it from anywhere in the
R session.
%>%
ds select(rainfall, min_temp, max_temp, sunshine) %>%
filter(rainfall==0) %T>%
assign("tmp", ., globalenv()) %>%
select(min_temp, max_temp, sunshine) %>%
summary()
## min_temp max_temp sunshine
## Min. :-8.70 Min. :-2.10 Min. : 0.0
## 1st Qu.: 7.30 1st Qu.:19.60 1st Qu.: 6.8
## Median :12.00 Median :24.40 Median : 9.6
## Mean :12.02 Mean :24.78 Mean : 8.7
## 3rd Qu.:16.80 3rd Qu.:29.80 3rd Qu.:11.1
## Max. :33.90 Max. :48.90 Max. :14.5
## NA's :612 NA's :676 NA's :76973
We can now access the variable tmp
:
print(tmp)
## # A tibble: 135,572 × 4
## rainfall min_temp max_temp sunshine
## <dbl> <dbl> <dbl> <dbl>
## 1 0 7.4 25.1 NA
## 2 0 12.9 25.7 NA
## 3 0 9.2 28 NA
## 4 0 14.3 25 NA
## 5 0 7.7 26.7 NA
## 6 0 9.7 31.9 NA
## 7 0 13.4 30.4 NA
## 8 0 8.4 24.6 NA
## 9 0 14.1 20.9 NA
## 10 0 9.8 25.6 NA
## # … with 135,562 more rows
Notice that for a tee-pipe curly braces will often be used to
encapsulate a sequence of operations for the first path of the
tee-pipe, allowing reference the data from the pipeline as the period
(.
).
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
