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My recent BARUG talk: Parametric Programming in R with replyr

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I want to share an edited screencast of my rehearsal for my recent San Francisco Bay Area R Users Group talk:

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jmount

Data Scientist and trainer at Win Vector LLC. One of the authors of Practical Data Science with R.

5 replies ›

  1. To make “let” easier to import I have moved it to a new low-dependency package: wrapr. Newer reply will re-export “let” so all the examples should continue to work. Please see here for some details.

  2. Great stuff. You can eliminate the temporary column name in your lazyeval::interp example, though it requires nesting: d %>% mutate_(.dots = stats::setNames(lazyeval::interp(~ is.na(VAR), VAR = as.name(cname)), rname))

    1. Thanks, I appreciate the support and the info.

      I tried it in the source of vignette('ParametricExample', package= 'replyr'), and for me that sets the result column to “is.na(x)” (an improvement), not exactly to “x_isNA” (my goal in that vignette). My packageVersion('lazyeval') is 0.2.0 (current CRAN version as of Feb 28, 2017).

      
library("dplyr")
d <- data.frame(x= c(1,NA))
cname <- 'x'
rname <- paste(cname, 'isNA', sep= '_')
print(rname)

 # [1] "x_isNA"

d <- d %>% 
  mutate_(.dots = stats::setNames(
    lazyeval::interp(~ is.na(VAR), 
                     VAR = as.name(cname)), rname))
print(d)

 # x is.na(x)
 # 1  1    FALSE
 # 2 NA     TRUE

  3. Oops I forgot you should surround the interp() call with list(). 

    library("dplyr")
d <- data.frame(x= c(1,NA))
cname <- 'x'
rname <- paste(cname, 'isNA', sep= '_')
print(rname)

 # [1] "x_isNA"

d %>%
  mutate_(.dots = stats::setNames(list(
    lazyeval::interp(~ is.na(VAR),
                     VAR = as.name(cname))), rname))
 # x x_isNA
 # 1  1  FALSE
 # 2 NA   TRUE

    1. Walter, Thanks for taking the time to work this out! I learned something here. I’ve update the matching vignette to remove all uses of rename_().

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