R has a very powerful array slicing ability that allows for some very slick data processing.
Category: Coding
match_order() to Align DataR Tip: Use match_order() to Align Data
R tip. Use wrapr::match_order() to align data.
magrittr and wrapr Pipes in R, an Examination
Let’s consider piping in R both using the magrittr package and using the wrapr package.
Continue reading magrittr and wrapr Pipes in R, an Examination
R Tip: Think in Terms of Values
R tip: first organize your tasks in terms of data, values, and desired transformation of values, not initially in terms of concrete functions or code.
I know I write a lot about coding in R. But it is in the service of supporting statistics, analysis, predictive analytics, and data science.
Rwithout data is like going to the theater to watch the curtain go up and down.(Adapted from Ben Katchor’s Julius Knipl, Real Estate Photographer: Stories, Little, Brown, and Company, 1996, page 72, “Excursionist Drama 2”.)
Usually you come to R to work with data. If you think and plan in terms of data and values (including introducing more data to control processing) you will usually work in much faster, explainable, and maintainable fashion.
R Tip: Use Named Vectors to Re-Map Values
R Tip: Use let() to Re-Map Names
Another R tip. Need to replace a name in some R code or make R code re-usable? Use wrapr::let().
R Tip: Break up Function Nesting for Legibility
There are a number of easy ways to avoid illegible code nesting problems in R.
In this R tip we will expand upon the above statement with a simple example.
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stringsAsFactors = FALSER Tip: Use stringsAsFactors = FALSE
Take Care If Trying the RPostgres Package
Take care if trying the new RPostgres database connection package. By default it returns some non-standard types that code developed against other database drivers may not expect, and may not be ready to defend against.
Danger, Will Robinson!
for() Class Loss IssuesR Tip: Introduce Indices to Avoid for() Class Loss Issues
Here is an R tip. Use loop indices to avoid for()-loops damaging classes.
Below is an R annoyance that occurs again and again: vectors lose class attributes when you iterate over them in a for()-loop.
d <- c(Sys.time(), Sys.time())
print(d)
#> [1] "2018-02-18 10:16:16 PST" "2018-02-18 10:16:16 PST"
for(di in d) {
print(di)
}
#> [1] 1518977777
#> [1] 1518977777
Notice we printed numbers, not dates/times. To avoid this problem introduce an index, and loop over that, not over the vector contents.
for(ii in seq_along(d)) {
di <- d[[ii]]
print(di)
}
#> [1] "2018-02-18 10:16:16 PST"
#> [1] "2018-02-18 10:16:16 PST"
Continue reading R Tip: Introduce Indices to Avoid for() Class Loss Issues