Entering edit mode
Heidi Dvinge
★
2.0k
@heidi-dvinge-2195
Last seen 10.3 years ago
Hello Patrick,
sorry for the delay in replying.
> Dear Heidi,
>
> I just found out about your R-package for analyzing PCR data. I
started to
> read about it but suffered with a silly problem.
> My output files look like the ones attached: 1 per sample and 3
technical
> replicate per file and used the following:
>
> files <- read.delim(file.path(path, "file listing.txt"))
> raw <- readCtData(files=files$File, path=path,
> n.features=48,feature=1,Ct=2,header=FALSE, SDS=FALSE)
>
> The readCtData command did not work. Could you give some assistance
to a
> non-frequent user of R?
>
In case this is still relevant, then the issue is that your file
doesn't
contain a lot of the standard high-throughput qPCR information, such
as
well position on a plate, and type of probe (control or 'real').
Therefore, you need to set these input to NULL. For examplke, this
should
work:
> files <- read.delim("file listing.txt", as.is=TRUE)
> raw <- readCtData(files=files$File, flag=NULL, feature=1,
type=NULL,
position=NULL, Ct=2, n.features=48)
Warning message:
In readCtData(files = files$File, flag = NULL, feature = 1, type =
NULL, :
One or more samples contain NAs. Consider replacing these with e.g.
Ct=40 now.
> show(raw)
An object of class "qPCRset"
Size: 48 features, 3 samples
Feature types: Target
Feature names: Hprt1 B2m Gapdh ...
Feature classes:
Feature categories: OK
Sample names: 31H 34H 35H ...
You can now continue as outlined in the vignette, and for example
check
the distribution of your Ct values:
> plotCtBoxes(raw)
> plotCtPairs(raw)
Note the warning about missing values. You can keep those as NA if you
prefer, but if you want to replace them you can say e.g.
> exprs(raw)[is.na(exprs(raw))] <- 40
HTH
\Heidi
> Thank you so much.
>
> Best wishes,
>
> Patrick
>
>
> Patrick De Boever, PhD, MSc
> Flemish Institute for Technological Research (VITO)
> Unit Environmental Risk and Health
> Industriezone Vlasmeer 7, 2400 Mol, Belgium
> Tel. + 32 14 33 51 45
> Fax. + 32 14 58 05 23
> patrick.deboever at vito.be<mailto:patrick.deboever at="" vito.be="">
>
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>
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