Question

更新：

tl; dr 是RJSONIO不再是两个选项中较快的选项。而rjson现在要快得多。

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我的印象是RJSONIO应该更快rjson 但是，我得到了相反的结果。

我的问题是：

是否可以/应该执行任何调整以改善RJSONIO的结果？（即，我忽略了什么吗？）

以下是使用真实数据的比较（其中U是json网页的内容）然后是模拟的json

## REAL DATA
library(microbenchmark)
> microbenchmark(RJSONIO::fromJSON(U), rjson::fromJSON(U))

Unit: milliseconds
                  expr       min        lq    median        uq      max
1   rjson::fromJSON(U)  29.46913  30.16218  31.74999  34.11012 158.6932
2 RJSONIO::fromJSON(U) 175.11514 181.67742 186.52871 195.90646 414.6160

> microbenchmark(RJSONIO::fromJSON(U, simplify=FALSE), rjson::fromJSON(U))
Unit: milliseconds
                                    expr       min       lq    median        uq        max
1                     rjson::fromJSON(U)  27.92341  28.7430  29.60091  30.63291 1 143.9478
2 RJSONIO::fromJSON(U, simplify = FALSE) 173.30136 179.5815 183.94315 190.17245 2 328.8996

模拟数据的示例

（类似结果）

# MOCK DATA
U <- toJSON(list(1:10, LETTERS, letters, rnorm(20)))

microbenchmark(RJSONIO::fromJSON(U), rjson::fromJSON(U))
# Unit: microseconds
#                   expr     min       lq   median       uq      max
# 1   rjson::fromJSON(U)  94.788 100.8650 105.6035 111.0740 3457.479
# 2 RJSONIO::fromJSON(U) 520.131 527.7775 533.2715 555.2415  942.136

包含iris数据集的示例2

Iris.JSON <- toJSON(iris)

microbenchmark(RJSONIO::fromJSON(Iris.JSON), rjson::fromJSON(Iris.JSON))
# Unit: microseconds
#                           expr      min       lq   median       uq       max
# 1   rjson::fromJSON(Iris.JSON)  229.669  235.571  238.511  241.423   260.164
# 2 RJSONIO::fromJSON(Iris.JSON) 1209.607 1224.793 1232.165 1238.953 12039.772

> sessionInfo()
R version 2.15.1 (2012-06-22)
Platform: x86_64-apple-darwin9.8.0/x86_64 (64-bit)

locale:
[1] en_US.UTF-8/en_US.UTF-8/en_US.UTF-8/C/en_US.UTF-8/en_US.UTF-8

attached base packages:
[1] stats     graphics  grDevices utils     datasets  methods   base

other attached packages:
[1] data.table_1.8.8 stringr_0.6.1    RJSONIO_1.0-1    rjson_0.2.11

loaded via a namespace (and not attached):
[1] plyr_1.7.1

Answer 1

> library('BBmisc')
> suppressAll(lib(c('RJSONIO','rjson','jsonlite','microbenchmark')))
> U <- toJSON(list(1:10, LETTERS, letters, rnorm(20)))
> microbenchmark(
+     rjson::toJSON(U),
+     RJSONIO::toJSON(U),
+     jsonlite::toJSON(U, dataframe = "column"),
+     times = 10
+ )
Unit: microseconds
                                      expr     min      lq      mean   median      uq       max neval cld
                          rjson::toJSON(U)  65.174  68.767 2002.7007  88.2675 103.151 19179.224    10   a
                        RJSONIO::toJSON(U) 299.186 304.832  482.8038 329.7210 493.683  1351.727    10   a
 jsonlite::toJSON(U, dataframe = "column") 485.985 501.381  555.4192 548.5935 587.083   708.708    10   a

测试system.time（）

> microbenchmark(
+     system.time(rjson::toJSON(U)),
+     system.time(RJSONIO::toJSON(U)),
+     system.time(jsonlite::toJSON(U, dataframe = "column")),
+     times = 10)
Unit: milliseconds
                                                   expr      min       lq     mean   median       uq      max neval cld
                          system.time(rjson::toJSON(U)) 112.0660 115.8677 119.8426 119.8372 121.6908 132.2111    10  ab
                        system.time(RJSONIO::toJSON(U)) 115.4223 118.0262 129.2758 120.5690 148.5175 151.6874    10   b
 system.time(jsonlite::toJSON(U, dataframe = "column")) 113.2674 114.9096 118.0905 117.8401 120.9626 123.6784    10  a

下面是几个包的比较。希望这些链接有所帮助......

1）New package: jsonlite. A smart(er) JSON encoder/decoder.

2）Improved memory usage and RJSONIO compatibility in jsonlite 0.9.15

3）A biased comparsion of JSON packages in R

Answer 2

https://cran.r-project.org/web/packages/jsonlite/vignettes/json-aaquickstart.html

请尝试jsonlite，这是我对json数据特别是嵌套

的最快体验

另见

https://rstudio-pubs-static.s3.amazonaws.com/31702_9c22e3d1a0c44968a4a1f9656f1800ab.html

RJSONIO vs rjson - 更好的调整

模拟数据的示例

2 个答案: