I have a dataset of 32 samples quantified using `salmon`. I used `tximport` to import the data:

    txi=tximport(c(a vector of file names),type="salmon",tx2gene=tx2gene)

I have created the colData and used `DESeqDataSetFromTximport` to construct the Deseq2 data set:

    dds <- DESeqDataSetFromTximport(txi = txi,colData = col_data,design = ~ Form)

In this case, all 32 samples are used, now I only want to use a subset of txi by choosing specific samples. Is there a way to subset my current txi rather than constructing a new txi using only the samples that I want?
The DESeq2 object is basically a SummarizedExperiment so you can subset this prior to running `DESeq` using standard operations such as `dds_use <- dds[,c(columns_to_keep]` where `columns_to_keep` is a numeric vector with the columns (samples) you want to use.