Thanks, Sean. I modified the codes and have generated a list of columns.I am 
working on convert a list of columns to a new data frame. It seems that there 
is no direct  API to do this.
----- 原始邮件 -----
发件人:Sean Owen <sro...@gmail.com>
收件人:ckgppl_...@sina.cn
抄送人:user <user@spark.apache.org>
主题:Re: calculate correlation between multiple columns and one specific column 
after groupby the spark data frame
日期:2022年03月16日 11点55分

Are you just trying to avoid writing the function call 30 times? Just put this 
in a loop over all the columns instead, which adds a new corr col every time to 
a list. 

On Tue, Mar 15, 2022, 10:30 PM  <ckgppl_...@sina.cn> wrote:
Hi all,
I am stuck at  a correlation calculation problem. I have a dataframe like 
below:groupiddatacol1datacol2datacol3datacol*corr_co000011234500001234650000242175000028932500003712350000335315I
 want to calculate the correlation between all datacol columns and corr_col 
column by each groupid.So I used the following spark scala-api 
codes:df.groupby("groupid").agg(functions.corr("datacol1","corr_col"),functions.corr("datacol2","corr_col"),functions.corr("datacol3","corr_col"),functions.corr("datacol*","corr_col"))
This is very inefficient. If I have 30 data_col columns, I need to input 30 
times functions.corr to calculate correlation.I have searched, it seems that 
functions.corr doesn't accept a List/Array parameter, and df.agg doesn't accept 
a function to be parameter.So any  spark scala API codes can do this job 
efficiently?
Thanks
Liang

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