XCMS Package - Retention time - r

Is there a simple way to get the list/array of retention times from a xcmsRaw object?
Example Code:
xraw <- xcmsRaw(cdfFile)
So for example getting information from it :
xraw#env$intensity
or
xraw#env$mz

You can see what slots are available in your xcmsRaw instance with
> slotNames(xraw)
[1] "env" "tic" "scantime"
[4] "scanindex" "polarity" "acquisitionNum"
[7] "profmethod" "profparam" "mzrange"
[10] "gradient" "msnScanindex" "msnAcquisitionNum"
[13] "msnPrecursorScan" "msnLevel" "msnRt"
[16] "msnPrecursorMz" "msnPrecursorIntensity" "msnPrecursorCharge"
[19] "msnCollisionEnergy" "filepath"
What you want is xraw#msnRt - it is a vector of numeric.
The env slot is a environment that stores 3 variables:
> ls(xraw#env)
[1] "intensity" "mz" "profile"
More details on the class itself at class?xcmsRaw.
EDIT: The msnRt slot is populated only if you specify includeMSn = TRUE and your input file must be in mzXML or mzML, not in cdf; if you use the faahKO example from ?xcmasRaw, you will see that
xr <- xcmsRaw(cdffiles[1], includeMSn = TRUE)
Warning message:
In xcmsRaw(cdffiles[1], includeMSn = TRUE) :
Reading of MSn spectra for NetCDF not supported
Also, xr#msnRt will only store the retention times for MSn scans, with n > 1. See the xset#rt where xset is an xcmsSet instance for the raw/corrected MS1 retention times as provided by xcms.
EDIT2: Alternatively, have a go with the mzR package
> library(mzR)
> cdffiles[1]
[2] "/home/lgatto/R/x86_64-unknown-linux-gnu-library/2.16/faahKO/cdf/KO/ko15.CDF"
> xx <- openMSfile(cdffiles[1])
> xx
Mass Spectrometry file handle.
Filename: /home/lgatto/R/x86_64-unknown-linux-gnu-library/2.16/faahKO/cdf/KO/ko15.CDF
Number of scans: 1278
> hd <- header(xx)
> names(hd)
[1] "seqNum" "acquisitionNum"
[3] "msLevel" "peaksCount"
[5] "totIonCurrent" "retentionTime"
[7] "basePeakMZ" "basePeakIntensity"
[9] "collisionEnergy" "ionisationEnergy"
[11] "highMZ" "precursorScanNum"
[13] "precursorMZ" "precursorCharge"
[15] "precursorIntensity" "mergedScan"
[17] "mergedResultScanNum" "mergedResultStartScanNum"
[19] "mergedResultEndScanNum"
> class(hd)
[1] "data.frame"
> dim(hd)
[1] 1278 19
but you will be outside of the default xcms pipeline if you take this route (although Steffen Neumann, from xcms, does know mzR very well, oubviously).
Finally, you are better of to use the Bioconductor mailing list of the xcms online forum if you want to maximise your chances to get feedback from the xcms developers.
Hope this helps.

Good answer but i was looking for this :
xraw <- xcmsRaw(cdfFile)
dp_index <- which(duplicated(rawMat(xraw)[,1]))
xraw_rt_dp <- rawMat(xraw)[,1]
xrawData.rt <- xraw_rt_dp[-dp_index]
Now :
xrawData.rt #contains the retention time.
Observation --> Using mzr package:
nc <- mzR:::netCDFOpen(cdfFile)
ncData <- mzR:::netCDFRawData(nc)
mzR:::netCDFClose(nc)
ncData$rt #contains the same retention time for the same input !!!

Related

How to find algo type(regression,classification) in Caret in R for all algos at once?

How do I find whether model type for all models at once? I know how to access this info if I know the algo name, e.g.:
library('Caret')
tail(name(getModelInfo()))
[1] "widekernelpls" "WM" "wsrf" "xgbLinear" "xgbTree"
[6] "xyf"
getModelInfo()$xyf$type
[1] "Classification" "Regression"
How do I see the $type for all the algos in one place?
Look at the help page ?models. Also, here are some links too.
Also:
> is_class <- unlist(lapply(mods, function(x) any(x$type == "Classification")))
> class_mods <- names(is_class)[is_class]
> head(class_mods)
[1] "ada" "AdaBag" "AdaBoost.M1" "amdai" "avNNet"
[6] "bag"

Case insensitive sort of vector of string in R

I have the following vector:
mylist <- c("MBT.LN.ID", "ISA51VG.LN.ID", "R848.LN.ID", "sHz.LN.ID", "FK565.LN.ID",
"bCD.LN.ID", "MALP2s.LN.ID", "ADX.LN.ID", "AddaVax.LN.ID", "FCA.LN.ID",
"Pam3CSK4.LN.ID", "D35.LN.ID", "ALM.LN.ID", "K3.LN.ID", "K3SPG.LN.ID",
"MPLA.LN.ID", "DMXAA.LN.ID", "cGAMP.LN.ID", "Poly_IC.LN.ID",
"cdiGMP.LN.ID")
I'd like to sort them alphabetically in case-insensitive manner.
The expected output is this:
[1] "AddaVax.LN.ID" "ADX.LN.ID" "ALM.LN.ID" "bCD.LN.ID" "cdiGMP.LN.ID" "cGAMP.LN.ID"
[7] "D35.LN.ID" "DMXAA.LN.ID" "FCA.LN.ID" "FK565.LN.ID" "ISA51VG.LN.ID" "K3.LN.ID"
[13] "K3SPG.LN.ID" "MALP2s.LN.ID" "MBT.LN.ID" "MPLA.LN.ID" "Pam3CSK4.LN.ID" "Poly_IC.LN.ID"
[19] "R848.LN.ID" "sHz.LN.ID"
I tried this but failed (Using R.3.2.0 alpha):
> sort(mylist)
[1] "ADX.LN.ID" "ALM.LN.ID" "AddaVax.LN.ID" "D35.LN.ID"
[5] "DMXAA.LN.ID" "FCA.LN.ID" "FK565.LN.ID" "ISA51VG.LN.ID"
[9] "K3.LN.ID" "K3SPG.LN.ID" "MALP2s.LN.ID" "MBT.LN.ID"
[13] "MPLA.LN.ID" "Pam3CSK4.LN.ID" "Poly_IC.LN.ID" "R848.LN.ID"
[17] "bCD.LN.ID" "cGAMP.LN.ID" "cdiGMP.LN.ID" "sHz.LN.ID"
Try
mylist[order(tolower(mylist))]
As noted by #Pascal, this is documented in help(Comparison) and sort is local specific. One Option is switching your local (for example Sys.setlocale("LC_TIME", "us")), but that could be inconvenient. Another option could be using gtools::mixedsort which could be also useful because you string also contains numbers.
library(gtools)
mixedsort(mylist)
# [1] "AddaVax.LN.ID" "ADX.LN.ID" "ALM.LN.ID" "bCD.LN.ID" "cdiGMP.LN.ID" "cGAMP.LN.ID" "D35.LN.ID" "DMXAA.LN.ID" "FCA.LN.ID" "FK565.LN.ID"
# [11] "ISA51VG.LN.ID" "K3.LN.ID" "K3SPG.LN.ID" "MALP2s.LN.ID" "MBT.LN.ID" "MPLA.LN.ID" "Pam3CSK4.LN.ID" "Poly_IC.LN.ID" "R848.LN.ID" "sHz.LN.ID"
> library(searchable)
> sort(ignore.case(mylist))
[1] "AddaVax.LN.ID" "ADX.LN.ID" "ALM.LN.ID" "bCD.LN.ID" "cdiGMP.LN.ID"
[6] "cGAMP.LN.ID" "D35.LN.ID" "DMXAA.LN.ID" "FCA.LN.ID" "FK565.LN.ID"
[11] "ISA51VG.LN.ID" "K3.LN.ID" "K3SPG.LN.ID" "MALP2s.LN.ID" "MBT.LN.ID"
[16] "MPLA.LN.ID" "Pam3CSK4.LN.ID" "Poly_IC.LN.ID" "R848.LN.ID" "sHz.LN.ID"

How to distinguish package namespace environment from other environment objects

Is there any way to programmatically distinguish between package environments and non-package environment objects? For example, the objects x and y below are both environments, with the same class and attributes.
x <- as.environment(cars)
y <- getNamespace("graphics")
However judging from the print method there is a difference:
> print(x)
<environment: 0x1d38118>
> print(y)
<environment: namespace:graphics>
Now suppose I have an arbitrary object, how can I determine which of the two it is (without looking at the output of print)? I would like to know this to determine how to store the object on disk. In case of the former I need to store the list representation of the environment (and perhaps its parents), but for the latter I would just store the name and version of the package.
isNamespace ?
isNamespace(y)
# [1] TRUE
isNamespace(x)
# [1] FALSE
And, for future reference, apropos is often helpful when you've got a question like this.
apropos("namespace")
# [1] "..getNamespace" ".BaseNamespaceEnv" ".getNamespace"
# [4] ".methodsNamespace" "asNamespace" "assignInMyNamespace"
# [7] "assignInNamespace" "attachNamespace" "fixInNamespace"
# [10] "getFromNamespace" "getNamespace" "getNamespaceExports"
# [13] "getNamespaceImports" "getNamespaceInfo" "getNamespaceName"
# [16] "getNamespaceUsers" "getNamespaceVersion" "isBaseNamespace"
# [19] "isNamespace" "loadedNamespaces" "loadingNamespaceInfo"
# [22] "loadNamespace" "namespaceExport" "namespaceImport"
# [25] "namespaceImportClasses" "namespaceImportFrom" "namespaceImportMethods"
# [28] "packageHasNamespace" "parseNamespaceFile" "requireNamespace"
# [31] "setNamespaceInfo" "unloadNamespace"

parent.env( x ) confusion

I've read the documentation for parent.env() and it seems fairly straightforward - it returns the enclosing environment. However, if I use parent.env() to walk the chain of enclosing environments, I see something that I cannot explain. First, the code (taken from "R in a nutshell")
library( PerformanceAnalytics )
x = environment(chart.RelativePerformance)
while (environmentName(x) != environmentName(emptyenv()))
{
print(environmentName(parent.env(x)))
x <- parent.env(x)
}
And the results:
[1] "imports:PerformanceAnalytics"
[1] "base"
[1] "R_GlobalEnv"
[1] "package:PerformanceAnalytics"
[1] "package:xts"
[1] "package:zoo"
[1] "tools:rstudio"
[1] "package:stats"
[1] "package:graphics"
[1] "package:utils"
[1] "package:datasets"
[1] "package:grDevices"
[1] "package:roxygen2"
[1] "package:digest"
[1] "package:methods"
[1] "Autoloads"
[1] "base"
[1] "R_EmptyEnv"
How can we explain the "base" at the top and the "base" at the bottom? Also, how can we explain "package:PerformanceAnalytics" and "imports:PerformanceAnalytics"? Everything would seem consistent without the first two lines. That is, function chart.RelativePerformance is in the package:PerformanceAnalytics environment which is created by xts, which is created by zoo, ... all the way up (or down) to base and the empty environment.
Also, the documentation is not super clear on this - is the "enclosing environment" the environment in which another environment is created and thus walking parent.env() shows a "creation" chain?
Edit
Shameless plug: I wrote a blog post that explains environments, parent.env(), enclosures, namespace/package, etc. with intuitive diagrams.
1) Regarding how base could be there twice (given that environments form a tree), its the fault of the environmentName function. Actually the first occurrence is .BaseNamespaceEnv and the latter occurrence is baseenv().
> identical(baseenv(), .BaseNamespaceEnv)
[1] FALSE
2) Regarding the imports:PerformanceAnalytics that is a special environment that R sets up to hold the imports mentioned in the package's NAMESPACE or DESCRIPTION file so that objects in it are encountered before anything else.
Try running this for some clarity. The str(p) and following if statements will give a better idea of what p is:
library( PerformanceAnalytics )
x <- environment(chart.RelativePerformance)
str(x)
while (environmentName(x) != environmentName(emptyenv())) {
p <- parent.env(x)
cat("------------------------------\n")
str(p)
if (identical(p, .BaseNamespaceEnv)) cat("Same as .BaseNamespaceEnv\n")
if (identical(p, baseenv())) cat("Same as baseenv()\n")
x <- p
}
The first few items in your results give evidence of the rules R uses to search for variables used in functions in packages with namespaces. From the R-ext manual:
The namespace controls the search strategy for variables used by functions in the package.
If not found locally, R searches the package namespace first, then the imports, then the base
namespace and then the normal search path.
Elaborating just a bit, have a look at the first few lines of chart.RelativePerformance:
head(body(chart.RelativePerformance), 5)
# {
# Ra = checkData(Ra)
# Rb = checkData(Rb)
# columns.a = ncol(Ra)
# columns.b = ncol(Rb)
# }
When a call to chart.RelativePerformance is being evaluated, each of those symbols --- whether the checkData on line 1, or the ncol on line 3 --- needs to be found somewhere on the search path. Here are the first few enclosing environments checked:
First off is namespace:PerformanceAnalytics. checkData is found there, but ncol is not.
Next stop (and the first location listed in your results) is imports:PerformanceAnalytics. This is the list of functions specified as imports in the package's NAMESPACE file. ncol is not found here either.
The base environment namespace (where ncol will be found) is the last stop before proceeding to the normal search path. Almost any R function will use some base functions, so this stop ensures that none of that functionality can be broken by objects in the global environment or in other packages. (R's designers could have left it to package authors to explicitly import the base environment in their NAMESPACE files, but adding this default pass through base does seem like the better design decision.)
The second base is .BaseNamespaceEnv, while the second to last base is baseenv(). These are not different (probably w.r.t. its parents). The parent of .BaseNamespaceEnv is .GlobalEnv, while that of baseenv() is emptyenv().
In a package, as #Josh says, R searches the namespace of the package, then the imports, and then the base (i.e., BaseNamespaceEnv).
you can find this by, e.g.:
> library(zoo)
> packageDescription("zoo")
Package: zoo
# ... snip ...
Imports: stats, utils, graphics, grDevices, lattice (>= 0.18-1)
# ... snip ...
> x <- environment(zoo)
> x
<environment: namespace:zoo>
> ls(x) # objects in zoo
[1] "-.yearmon" "-.yearqtr" "[.yearmon"
[4] "[.yearqtr" "[.zoo" "[<-.zoo"
# ... snip ...
> y <- parent.env(x)
> y # namespace of imported packages
<environment: 0x116e37468>
attr(,"name")
[1] "imports:zoo"
> ls(y) # objects in the imported packages
[1] "?" "abline"
[3] "acf" "acf2AR"
# ... snip ...

spChFIDs() on level 1 or higher map-files

Hopefully (one of) the last question on map-files.
Why is this not working, and how would I do that right?
load(url('http://gadm.org/data/rda/CUB_adm1.RData'))
CUB <- gadm
CUB <- spChFIDs(CUB, paste("CUB", rownames(CUB), sep = "_"))
Thank you very much!!!
seems to work with row.names()
load(url('http://gadm.org/data/rda/CUB_adm1.RData'))
CUB <- gadm
CUB <- spChFIDs(CUB, paste("CUB", row.names(CUB), sep = "_"))
The answer is apparent once one reads the help for ?row.names() and ?rownames().
The rownames() function only knows something about matrix-like objects, and CUB is not one of those, hence it doesn't have row names that rownames() can find:
> rownames(CUB)
NULL
row.names() is different, it is an S3 generic function and that means package authors can write methods for specific types of objects such that the row names of those objects can be extracted.
Here is a list of the methods available for row.names() in my current session, with the sp package loaded:
> methods(row.names)
[1] row.names.data.frame
[2] row.names.default
[3] row.names.SpatialGrid*
[4] row.names.SpatialGridDataFrame*
[5] row.names.SpatialLines*
[6] row.names.SpatialLinesDataFrame*
[7] row.names.SpatialPixels*
[8] row.names.SpatialPoints*
[9] row.names.SpatialPointsDataFrame*
[10] row.names.SpatialPolygons*
[11] row.names.SpatialPolygonsDataFrame*
Non-visible functions are asterisked
The class of the object CUB is:
> class(CUB)
[1] "SpatialPolygonsDataFrame"
attr(,"package")
[1] "sp"
So what is happening is that the SpatialPolygonsDataFrame method of the row.names() function is being used and it knows where to find the required row names.

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