Dan,
That was very helpful. When I run your code on a different computer than the
first one I was working on, I see this:
ghic> input
[Seq (SeqLabel {unSL = "Rosalind_6404"}) (SeqData {unSD =
"CCTGCGGAAGATCGGCACTAGAATAGCCAGAACCGTTTCTCTGAGGCTTCCGGCCTTCCCTCCCACTAATAATTCTGAGG"})
Nothing,Seq (SeqLabel {unSL = "Rosalind_5959"}) (SeqData {unSD =
"CCATCGGTAGCGCATCCTTAGTCCAATTAAGTCCCTATCCAGGCGCTCCGCCGAAGGTCTATATCCATTTGTCAGCAGACACGC"})
Nothing,Seq (SeqLabel {unSL = "Rosalind_0808"}) (SeqData {unSD =
"CCACCCTCGTGGTATGGCTAGGCATTCAGGAACCGGAGAACGCTTCAGACCAGCCCGGACTGGGAACCTGCGGGCAGTAGGTGGAAT"})
Nothing]
ghic> :t input
input :: [Sequence]
Which is entirely different from what I’m seeing on the other computer (see
below). Both are Macs. As far as I can tell, all versions of the Haskell
Platform and the modules are the same.
Any ideas?
Ken
> On Oct 20, 2014, at 1:49 PM, Dan Fornika <dforn...@gmail.com> wrote:
>
> Hi Ken,
>
> I've also been working on the rosalind.info problem set. If you'd like to
> see my answer for this problem, you can see it here:
>
> https://github.com/dfornika/rosalind/blob/master/04_gc_content/04_gc_content.hs
>
> If you'd prefer to work through the problem yourself, I can offer some advice
> to get started. The internal sequence data in the Sequence type in
> Bio.Sequence.Fasta is a lazy bytestring. You can access the sequence data
> with the 'seqdata' function from Bio.Sequence.Fasta, and convert it to a
> 'plain old' String with 'toStr'.
>
> If you need to work with they bytestrings, you can import
> Data.ByteString.Lazy.Char8. It should be imported 'qualified' so that it
> doesn't conflict with functions from the Prelude.
>
> Here is some code. I haven't had a chance to test it, so I apologize for any
> bugs.
>
> Dan
>
> module Main where
>
> import Bio.Core.Sequence
> import Bio.Sequence.Fasta
> import qualified Data.ByteString.Lazy.Char8 as B -- not necessary for this
> example, but this is how you would import the bytestring functions.
>
> main :: IO()
> main = do
> input <- readFasta "./input.fasta"
> let seqs = map (toStr . seqdata) seqs
> mapM_ putStrLn seqs
>
> On Mon, Oct 20, 2014 at 9:27 AM, Youens-Clark, Charles Kenneth - (kyclark)
> <kycl...@email.arizona.edu> wrote:
> I’m currently working my way through the problems at “rosalind.info,”
> implementing each of my solutions in Perl, Python, and Haskell. I’m stuck on
> the “GC” problem (http://rosalind.info/problems/gc/) as I need to parse a
> FASTA file with "Bio.Sequence.Fasta.”
>
> In ghci, I can easily do this:
>
> ghci> let f = readFasta "input.fasta"
> ghci> f
> [ID -----------------------------------------------------------------
> Rosalind_6404
>
> COMMENT ------------------------------------------------------------
>
>
> DATA ---------------------------------------------------------------
> 0 CCTGCGGAAG ATCGGCACTA GAATAGCCAG AACCGTTTCT CTGAGGCTTC CGGCCTTCCC
> 60 TCCCACTAAT AATTCTGAGG,ID
> -----------------------------------------------------------------
> Rosalind_5959
>
> COMMENT ------------------------------------------------------------
>
>
> DATA ---------------------------------------------------------------
> 0 CCATCGGTAG CGCATCCTTA GTCCAATTAA GTCCCTATCC AGGCGCTCCG CCGAAGGTCT
> 60 ATATCCATTT GTCAGCAGAC ACGC,ID ————————————————————————————————
> …
>
> So I know it’s working, but I can’t figure out what to do with “f” now. I
> can see it’s type:
>
> ghci> :t f
> f :: IO
> [Bio.Sequence.SeqData.Sequence Bio.Sequence.SeqData.Unknown]
>
> But what do I do with “f” to, say, iterate over the sequences and count G/C
> content, get the length of the sequence, etc.?
>
> Thanks,
>
> Ken
>
