Iquery select dimension names in R


#1

My goal is to store R matrix in scidb and be able to use them in R. These matrices have rownames and colnames.
In scidb I store the rownames and colnames as non-integer (string) dimension names. To get the values, I casted the array dimensions to int64. For rownames and colnames, I thought it would be possible through iquery. But such query did not work.
Please advise. Many thanks.

AQL% select * from show(A); {i} schema {0} "A<value:double> [sample(string)=*,1000,0,variable(string)=*,1000,0]" AQL% select * from A:sample;

## in R options(scidb.debug=TRUE) iquery(query='select * from A:sample', afl=FALSE) select * from A:sample Error in scidbquery(query, afl) : UserQueryException in file: src/query/parser/QueryParser.cpp function: parse line: 81 Error id: scidb::SCIDB_SE_PARSER::SCIDB_LE_QUERY_PARSING_ERROR Error description: Error during query parsing. Query parser failed with error 'syntax error, unexpected '*', expecting AS'. select * from A:sample ^ Failed query id: 1100902404516


#2

Yes, sorry right now non-integer dimension support in both SciDB and the scidb package for R is spotty. Since the support is not really there in SciDB for it, I didn’t put much effort into supporting that for the R side of things.

Alex has implemented a few new operators recently (to be released in SciDB 13.6) that improve the story somewhat. They require manual mapping of non-integer dimensions, but they work.

My plan is to try to integrate this new approach into the R package that hides most of the manual details from the user.

I expect a major update of the R package by mid-July that will have better NID support, expanded linear algebra functions, and expanded aggregate support.