# Adding Aggregate methods - dsSynthetic

**URL:** <https://datashield.discourse.group/t/adding-aggregate-methods-dssynthetic/710>\
**Category:** Analyst Support\
**Created:** [10 February 2023 09:17 UTC](https://datashield.discourse.group/t/adding-aggregate-methods-dssynthetic/710 "2023-02-10T09:17:03Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![InesAmine](https://avatars.discourse-cdn.com/v4/letter/i/c6cbf5/32.png) [@InesAmine](https://datashield.discourse.group/u/InesAmine)\
**Post date:** [10 February 2023 09:17 UTC](https://datashield.discourse.group/t/adding-aggregate-methods-dssynthetic/710/1 "2023-02-10T09:17:03Z")

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Hi all

I was interested in using the package dsSynthetics, with the function ds.syn(). When I try it on the data used in the Vignette it works properly. ( [vignette](https://tombisho.github.io/synthetic_bookdown/synthpop.html#getting-set-up) ).

Then, I tried using the same code on the Ninfea italian cohort:

```auto
builder <- DSI::newDSLoginBuilder()
builder$append(server = "server1", url = "https://www.lifecycle.unito.it/",driver = "OpalDriver", 
               user = "----", password = "-----")
logindata <- builder$build()
connections <- DSI::datashield.login(logins = logindata, assign = TRUE, 
                                     symbol = "DST")
synth_data = ds.syn(data = "DST", method = "cart", m = 1, seed = 123)$server1$Data$syn

```

And I get this error:

```auto
"Command 'synDS(\"DST\", \"cart\", 1, NULL, FALSE, 123)' failed on 'server1': No such DataSHIELD 'AGGREGATE' method with name: synDS"

```

I checked and the synDS function is indeed not in the list of available methods when I run datashield.methods(connections, type = “aggregate”). More generally, it is not the first time I get an error like this for an ASSIGN or AGGREGATE method, that Datashield cannot find.

Does it mean the function is not installed/autorized by the cohort server? Can I install it myself? I looked at the Opal documentation ([DataSHIELD — Opal documentation (obiba.org)](https://opaldoc.obiba.org/en/latest/web-user-guide/administration/datashield.html#administrate-permission)) but I don’t see any codes to try.

Versions of packages used:

- dsBase & dsBaseClient: 6.2.0.
- dsSynthetic: 0.0.2.
- dsOpal: 1.4.0
- DSI: 1.5.0

Thanks in advance Inès

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<div class="post-metadata">

**Author:** ![swheater](https://yyz2.discourse-cdn.com/free1/user_avatar/datashield.discourse.group/swheater/32/182_2.png) [@swheater](https://datashield.discourse.group/u/swheater)\
**Post date:** [10 February 2023 10:10 UTC](https://datashield.discourse.group/t/adding-aggregate-methods-dssynthetic/710/2 "2023-02-10T10:10:48Z")

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Inès,

What you are seeing does imply that the dsSynthetic package is not installed on the lifecycle.unito.it server. To install the package will require administrative access to the lifecycle.unito.it server.

I have name of a person at NINFEA who may be of help in this matter, contact me if you think it could help ([stuart.wheater@arjuna.com](mailto:stuart.wheater@arjuna.com))

Stuart