Go to TogaWare.com Home Page. Data Science Desktop Survival Guide
by Graham Williams
Duck Duck Go

Replacing Missing Values

20201026 See Section 9.11 to impute (guess) values to replace missing values.

To replace missing values (NA) in a data set with a specific default value, like 0 for numeric data, we can use tidyr::replace_na() within a pipeline. In the following example only the numeric columns of the dataset are considered dplyr::across() the dataset, by checking tidyselect::where() the data base::is.numeric().

ds %>%
  mutate(across(where(is.numeric), ~replace_na(.x, 0)))
## # A tibble: 176,747 x 24
##    date       location min_temp max_temp rainfall evaporation sunshine
##    <date>     <chr>       <dbl>    <dbl>    <dbl>       <dbl>    <dbl>
##  1 2008-12-01 Albury       13.4     22.9      0.6         4.8      8.5
##  2 2008-12-02 Albury        7.4     25.1      0           4.8      8.5
##  3 2008-12-03 Albury       12.9     25.7      0           4.8      8.5
##  4 2008-12-04 Albury        9.2     28        0           4.8      8.5
##  5 2008-12-05 Albury       17.5     32.3      1           4.8      8.5
##  6 2008-12-06 Albury       14.6     29.7      0.2         4.8      8.5
##  7 2008-12-07 Albury       14.3     25        0           4.8      8.5
##  8 2008-12-08 Albury        7.7     26.7      0           4.8      8.5
##  9 2008-12-09 Albury        9.7     31.9      0           4.8      8.5
## 10 2008-12-10 Albury       13.1     30.1      1.4         4.8      8.5
## # ... with 176,737 more rows, and 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 <dbl>, pressure_9am <dbl>, pressure_3pm <dbl>,
## #   cloud_9am <dbl>, cloud_3pm <dbl>, temp_9am <dbl>, temp_3pm <dbl>,
## #   rain_today <fct>, risk_mm <dbl>, rain_tomorrow <fct>


Support further development by purchasing the PDF version of the book.
Other online resources include the GNU/Linux Desktop Survival Guide.
Books available on Amazon include Data Mining with Rattle and Essentials of Data Science.
Popular open source software includes rattle and wajig.
Hosted by Togaware, a pioneer of free and open source software since 1984.
Copyright © 2000-2020 Togaware Pty Ltd. . Creative Commons ShareAlike V4.