This will do:

|> samp <- read.FCS(system.file("extdata","0877408774.B08", package="flowCore"))
> apply(exprs(samp),2,range)
      FSC-H SSC-H    FL1-H FL2-H    FL3-H FL1-A    FL4-H Time
[1,]85     11     1.000      1     1.000      0     1.000     1
[2,]1023   1023  3681.141  10000  3304.164   1023  9910.371   626
> samp.trans <- transform(samp, trans.FL4.H =10^(`FL4-H`/1024))
> apply(exprs(samp.trans),2,range)
      FSC-H SSC-H    FL1-H FL2-H    FL3-H FL1-A    FL4-H Time  trans.FL4.H
[1,]85     11     1.000      1     1.000      0     1.000     1  1.002251e+00
[2,]1023   1023  3681.141  10000  3304.164   1023  9910.371   626  4.765375e+09|

Mike Jiang

On 07/03/2013 04:10 AM, Telma Fernandes [guest] wrote:

> I wanna know how to do transformation of the channel four (FLH 4) without using the standard transformations offer by the flowCore package?
>
> The values of the channel four are between 1 and 4096 and i need to convert in values between 1 and 246 with the rule 10^(x/1024).
>
> Thank you.
>
>   -- output of sessionInfo():
>
> R version 2.15.1 (2012-06-22)
> Platform: i386-pc-mingw32/i386 (32-bit)
>
> locale:
> [1] LC_COLLATE=Portuguese_Portugal.1252  LC_CTYPE=Portuguese_Portugal.1252    LC_MONETARY=Portuguese_Portugal.1252
> [4] LC_NUMERIC=C                         LC_TIME=Portuguese_Portugal.1252
>
> attached base packages:
> [1] stats     graphics  grDevices utils     datasets  methods   base
>
> other attached packages:
>   [1] latticeExtra_0.6-24 RColorBrewer_1.0-5  flowViz_1.22.0      lattice_0.20-15     flowCore_1.24.2
>   [6] rrcov_1.3-3         pcaPP_1.9-49        mvtnorm_0.9-9995    robustbase_0.9-8    Biobase_2.18.0
> [11] BiocGenerics_0.4.0
>
> loaded via a namespace (and not attached):
>   [1] feature_1.2.8      graph_1.36.2       grid_2.15.1        hexbin_1.26.2      IDPmisc_1.1.17     KernSmooth_2.23-10
>   [7] ks_1.8.12          MASS_7.3-23        stats4_2.15.1      tools_2.15.1
>
> --
> Sent via the guest posting facility at bioconductor.org.


	[[alternative HTML version deleted]]

