HI, sorry for the latency.
I can't replicate the error with:
A <- as.scidb(matrix(1,100,100))
Perhaps you're on an old version of SciDB? This works OK with 12.12 and 14.3 at least.
As a work-around perhaps consider using the more efficient 'build' function, for example:
A <- build(1.0, dim=c(100,100), type="double")
(that approach builds the data on the SciDB side instead of in R and then uploading it to SciDB).
You can certainly transfer matrices between R and SciDB using 'as.scidb' -- again, maybe you have too old a version of SciDB?