# [R] Problem with random numbers/seed

Uwe Ligges ||gge@ @end|ng |rom @t@t|@t|k@tu-dortmund@de
Fri Jun 21 19:03:05 CEST 2019

```What does not work?

For me it works under R-3.6.0:

x<-1:500
set.seed(12345671)
j<-sample(1:length(x),size=60); y<-x[j]
summary(j)

RNGversion("3.5.3")
set.seed(12345671)
j<-sample(1:length(x),size=60); y<-x[j]
summary(j)

Now I get the results you got udner the old R.

Best,
Uwe Ligges

On 21.06.2019 18:39, Steven Yen wrote:
> Thanks. Somewhat of a mystery. The older version I had was R-3.5.3patched.
> I cannot get the RNGversion command to run. Can you help? Thanks.
>
> On 6/22/2019 12:25 AM, Uwe Ligges wrote:
>> See the NEWS, the RNG has been changed, use RNGversion
>>
>> On 21.06.2019 18:10, Steven Yen wrote:
>>> Dear all,
>>> I did all this work with older R (R-3.5.3.patched and older)
>>> but now with R3.6 I cannot replicate the results.
>>> Below I sample 60 observations from 1:500 using the sample command with
>>> a random seed of 123. I get different results. Advice appreciated.
>>> Steven Yen
>>>
>>>   > # Run under R-3.6.0
>>>   > x<-1:500
>>>   > set.seed(12345671)
>>>   > j<-sample(1:length(x),size=60); y<-x[j]
>>>   > summary(y)
>>>      Min. 1st Qu.  Median    Mean 3rd Qu.    Max.
>>>      26.0   134.2   240.0   249.8   368.0   500.0
>>>
>>>   > # Run under R-3.5.3.patched
>>>   > x<-1:500
>>>   > set.seed(12345671)
>>>   > j<-sample(1:length(x),size=60); y<-x[j]
>>>   > summary(y)
>>>      Min. 1st Qu.  Median    Mean 3rd Qu.    Max.
>>>       9.0   122.2   205.0   236.1   364.2   493.0
>>>
>>
>>
>> Under R-3.6.0  use, e.g.
>> RNGversion("3.5.2")
>> to get reproducible results from the older RNG.
>>
>> Best,
>> Uwe Ligges
>>
>>
>
> --
> styen using ntu.edu.tw  (S.T. Yen)
>

```