pander: An R Pandoc Writer

## ---- echo = FALSE, message = FALSE--------------------------------------
knitr::opts_chunk$set(collapse = T, comment = "#>")
library(pander)
library(futile.logger)
evalsOptions('graph.name', 'test')
evalsOptions('graph.dir', 'my_plots')
evalsOptions('graph.output', 'jpg')

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evals('1:10')

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evals('1:10', output = c('result', 'output'))

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evals('x')[[1]]$msg
evals('as.numeric("1.1a")')[[1]]$msg

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evals('plot(mtcars)')[[1]]$result

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evals('plot(mtcars)', graph.dir = 'my_plots', graph.output = 'jpg')[[1]]$result

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## generating dataset
set.seed(1)
df <- mtcars[, c('hp', 'wt')]
df$factor <- sample(c('Foo', 'Bar', 'Foo bar'), size = nrow(df), replace = TRUE)
df$factor2 <- sample(c('Foo', 'Bar', 'Foo bar'), size = nrow(df), replace = TRUE)
df$time <- 1:nrow(df)

## ----echo=FALSE----------------------------------------------------------
## loading packages
require(ggplot2, quietly = TRUE)
require(lattice, quietly = TRUE)

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evalsOptions('graph.unify', TRUE)
evals('histogram(df$hp, main = "Histogram with lattice")')[[1]]$result
evals('ggplot(df) + geom_histogram(aes(x = hp), binwidth = 50) + ggtitle("Histogram with ggplot2")')[[1]]$result
evalsOptions('graph.unify', FALSE)

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x <- evals('1:10', log = 'foo')

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evalsOptions('log', 'evals')
flog.threshold(TRACE, 'evals')
x <- evals('1:10', cache.time = 0)

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t <- tempfile()
flog.appender(appender.file(t), name = 'evals')
x <- evals('1:10', log = 'evals')
readLines(t)
# revert back to console
flog.appender(appender.console(), name = 'evals')

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evalsOptions('cache.time', 0)
evalsOptions('log', 'evals')
flog.threshold(TRACE, 'evals')

## ------------------------------------------------------------------------
system.time(evals('1:1e5'))
system.time(evals('1:1e5'))

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res <- evals('1:1e5', cache.mode = 'disk', cache.dir = 'cachedir')
list.files('cachedir')

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x <- mtcars$hp
y <- 1e3
system.time(evals('sapply(rep(x, y), mean)'))

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f <- sapply
g <- rep
h <- mean
X <- mtcars$hp * 1
Y <- 1000
system.time(evals('f(g(X, Y), h)'))

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x <- 1
res <- evals('x <- 1:10;')

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evals('x <- 1:10; x[3]')[[2]]$result

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system.time(evals('plot(mtcars)'))
system.time(evals('plot(mtcars)'))

## ---- echo = FALSE, message = FALSE--------------------------------------
unlink('cachedir', recursive = TRUE, force = TRUE)
unlink('my_plots', recursive = TRUE, force = TRUE)