# Issue with RData

**URL:** <https://discourse.julialang.org/t/issue-with-rdata/5748>\
**Category:** General Usage\
**Created:** [September 6, 2017, 7:33pm UTC](https://discourse.julialang.org/t/issue-with-rdata/5748 "2017-09-06T19:33:24Z")\
**Posts on this page:** 9\
**Page:** 1

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**Author:** ![pegger0709](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/pegger0709/32/1811_2.png) [@pegger0709](https://discourse.julialang.org/u/pegger0709)\
**Post date:** [September 6, 2017, 7:33pm UTC](https://discourse.julialang.org/t/issue-with-rdata/5748/1 "2017-09-06T19:33:24Z")

</div>

Hello,  
I am using julia v0.6.0 on the server at work and having a problem loading RData files using the RData package. I ran the following:

“”"  
using RData  
ResponseMatrix = load(“Dahaniel-DoOR.data-6436660/data/response.matrix.RData”,convert=true)  
“”"

and got the following error message

ERROR: AssertionError: FileIO.detect\_rdata(io)

with the following stack trace

Stacktrace:  
[1] load(::FileIO.Stream{FileIO.DataFormat{:RData},GZip.GZipStream}, ::Array{Any,1}) at /data1/homes/pee3/.julia/v0.6/RData/src/RData.jl:53  
[2] gzopen(::RData.##4#5{Array{Any,1},FileIO.File{FileIO.DataFormat{:RData}}}, ::String) at /data1/homes/pee3/.julia/v0.6/GZip/src/GZip.jl:268  
[3] #load#3(::Array{Any,1}, ::Function, ::FileIO.File{FileIO.DataFormat{:RData}}) at /data1/homes/pee3/.julia/v0.6/RData/src/RData.jl:46  
[4] (::FileIO.#kw##load)(::Array{Any,1}, ::FileIO.#load, ::FileIO.File{FileIO.DataFormat{:RData}}) at ./:0  
[5] #load#13(::Array{Any,1}, ::Function, ::String) at /data1/homes/pee3/.julia/v0.6/FileIO/src/loadsave.jl:52  
[6] (::FileIO.#kw##load)(::Array{Any,1}, ::FileIO.#load, ::String) at ./:0

Does anyone know what might be going on? Using other julia packages on the server doesn’t seem to cause problems.  
Thanks,  
Philip

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<div class="post-metadata">

**Author:** ![mkborregaard](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/mkborregaard/32/556_2.png) [@mkborregaard](https://discourse.julialang.org/u/mkborregaard)\
**Post date:** [September 6, 2017, 7:47pm UTC](https://discourse.julialang.org/t/issue-with-rdata/5748/2 "2017-09-06T19:47:33Z")

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What’s in the data file? Could be objects of a class not supported?

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**Author:** ![dmbates](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/dmbates/32/44_2.png) [@dmbates](https://discourse.julialang.org/u/dmbates)\
**Post date:** [September 6, 2017, 9:13pm UTC](https://discourse.julialang.org/t/issue-with-rdata/5748/3 "2017-09-06T21:13:09Z")

</div>

Do you know what compression type was used in creation of the RData file? Under Linux I can use

```julia
bates@lunchbox:~$ file ~/ml10m.rda
/workspace/bates/ml10m.rda: gzip compressed data, from Unix

```

to determine that.

R allows you to use different compression types when creating an RData file but we only allow gzip compression when reading with the RData package.

One of the items on my “To Do” list is to create a PR to allow for xz and bzip2 compression.

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<div class="post-metadata">

**Author:** ![dmbates](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/dmbates/32/44_2.png) [@dmbates](https://discourse.julialang.org/u/dmbates)\
**Post date:** [September 6, 2017, 9:19pm UTC](https://discourse.julialang.org/t/issue-with-rdata/5748/4 "2017-09-06T21:19:55Z")

</div>

By the way, what would the preferred package(s) be to open a file, check for gzip, bzip2 or xz compression, then uncompress using the detected compression scheme?

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**Author:** ![pfarndt](https://avatars.discourse-cdn.com/v4/letter/p/8dc957/32.png) [@pfarndt](https://discourse.julialang.org/u/pfarndt)\
**Post date:** [May 30, 2018, 11:11am UTC](https://discourse.julialang.org/t/issue-with-rdata/5748/5 "2018-05-30T11:11:46Z")

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This does not seem to be resolved yet. Today I got similar problems and could not even read a simple `.Rdata` file.

In R (version 3.5.0) I generate the file with:

```r
> a <- 42
> save(a,file="tmp.Rdata")

```

and then in Julia (version 0.6.2):

```julia
julia> Pkg.status("RData")
 - RData 0.4.0

julia> using RData
WARNING: Method definition unix2zdt(Real) in module TimeZones at /Users/a/.julia/v0.6/TimeZones/src/conversions.jl:122 overwritten in module RData at /Users/a/.julia/v0.6/RData/src/convert.jl:201.

julia> load("tmp.Rdata")
Error encountered while loading "/Users/a/tmp.Rdata".
Fatal error:
ERROR: UndefVarError: load not defined
Stacktrace:
 [1] #load#27(::Array{Any,1}, ::Function, ::FileIO.File{FileIO.DataFormat{:GZIP}}) at /Users/a/.julia/v0.6/FileIO/src/loadsave.jl:180
 [2] load(::FileIO.File{FileIO.DataFormat{:GZIP}}) at /Users/a/.julia/v0.6/FileIO/src/loadsave.jl:167
 [3] #load#13(::Array{Any,1}, ::Function, ::String) at /Users/a/.julia/v0.6/FileIO/src/loadsave.jl:113
 [4] load(::String) at /Users/a/.julia/v0.6/FileIO/src/loadsave.jl:113

```

while I can read the file `iris.rda`, which ships with `Rdatasets`, without any problem:

```julia
julia> load("/Users/a/.julia/v0.6/RDatasets/data/datasets/iris.rda")
Dict{String,Any} with 1 entry:
  "iris" => 150×5 DataFrames.DataFrame…

```

Any help is appreciated.

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<div class="post-metadata">

**Author:** ![Tamas\_Papp](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/tamas_papp/32/25949_2.png) [@Tamas\_Papp](https://discourse.julialang.org/u/Tamas_Papp)\
**Post date:** [May 30, 2018, 11:58am UTC](https://discourse.julialang.org/t/issue-with-rdata/5748/6 "2018-05-30T11:58:42Z")

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> [@dmbates](#):
>
> what would the preferred package(s) be to open a file, check for gzip, bzip2 or xz compression, then uncompress using the detected compression scheme?

I don’t know anything better than a long chain of `try ... catch` blocks, but perhaps you could make a feature request in

> **[GitHub - JuliaIO/TranscodingStreams.jl: Simple, consistent interfaces for any...](https://github.com/JuliaIO/TranscodingStreams.jl)**
>
> Simple, consistent interfaces for any codec. Contribute to JuliaIO/TranscodingStreams.jl development by creating an account on GitHub.

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<div class="post-metadata">

**Author:** ![pfarndt](https://avatars.discourse-cdn.com/v4/letter/p/8dc957/32.png) [@pfarndt](https://discourse.julialang.org/u/pfarndt)\
**Post date:** [May 30, 2018, 12:20pm UTC](https://discourse.julialang.org/t/issue-with-rdata/5748/7 "2018-05-30T12:20:50Z")

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In my above example both files seem to be properly gzip encoded:

```julia
> gzip -t -v /Users/arndt/.julia/v0.6/RDatasets/data/datasets/iris.rda
/Users/a/.julia/v0.6/RDatasets/data/datasets/iris.rda: OK
> gzip -t -v tmp.Rdata 
tmp.Rdata: OK

```

And with `load` I can read one file but not the other.

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<div class="post-metadata">

**Author:** ![Yifan\_Liu](https://avatars.discourse-cdn.com/v4/letter/y/4da419/32.png) [@Yifan\_Liu](https://discourse.julialang.org/u/Yifan_Liu)\
**Post date:** [May 30, 2018, 3:30pm UTC](https://discourse.julialang.org/t/issue-with-rdata/5748/8 "2018-05-30T15:30:03Z")

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Could you try to use the extension .RData instead of .Rdata?

I use RData.jl a lot, and it works well.

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<div class="post-metadata">

**Author:** ![pfarndt](https://avatars.discourse-cdn.com/v4/letter/p/8dc957/32.png) [@pfarndt](https://discourse.julialang.org/u/pfarndt)\
**Post date:** [May 30, 2018, 7:20pm UTC](https://discourse.julialang.org/t/issue-with-rdata/5748/9 "2018-05-30T19:20:52Z")

</div>

Yep - that solved the problem - the two extension which work are: `.RData` and `.rda`. E.g.

```julia
julia> load("tmp.rda")
Dict{String,Any} with 1 entry:
  "a" => 42.0

```

Thanks a lot.