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hadley/object_size.md

Last active June 27, 2016 00:07
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object_size.md 
diamonds <- ggplot2::diamonds
pryr::object_size(diamonds)
#> 3.46 MB

diamonds2 <- transform(diamonds, price_per_carat = price / carat)
pryr::object_size(diamonds2)
#> 3.89 MB

# Size of both data frames combined
pryr::object_size(diamonds, diamonds2)
#> 3.89 MB
@decisionstats
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why does a data.table have a bigger objectsize than same data.frame

@mattdowle
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@decisionstats how much bigger do you see? I see 0.0006 MB bigger for one extra internal attribute of fixed size. Unless perhaps your data.table has had an automatic index added. DT[ someCol == someVal, ] does that by default for convenience and instant lookup if someCol is queried again. In which case both base::object.size() and pryr::object_size() will include the size of the data.table index which is added as an attribute.

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