Export Raman Spectra/Maps in the Witec ASCII Graph format to be used by external software (e.g. ImageLab).
write.txt.Witec.Graph( x, file = NULL, type = "map", graphname = NULL, scan_params = NULL, encoding = "latin1" )
| x | a |
|---|---|
| file | path to the export file. Specify one template filepath, the three text files for the Witec ASCII Graph format are generated automatically with the infixed " (Header)", " (X-Axis)" and " (Y-Axis)" added before the file extension. |
| type | currently only "map" is supported. |
| graphname | Add a custom GraphName; If not specified the function generates it from |
| scan_params | list; contains information on the scale and origin of the scan and may contain the members "ScanUnit", "ScanWidth", "ScanHeight", "ScanOriginX", "ScanOriginY", "ScanOriginZ" (take a look at the examples in case your hyperSpec object contains spatial information in "real world units" and you want to generate this list from the data). |
| encoding | character; specifies the encoding of non-ASCII characters (e.g. for the unit), "latin1" is correct for most external software running under Windows. |
if (FALSE) { library(hyperSpec) library(hyperSpec.utils) # This example uses the chondro dataset contained in {hyperSpec} # prepare a list for meta info in real world units calculated from values of # the hyperSpec object scan_params <- list( ScanUnit = "µm", ScanWidth = diff(range(chondro$x)) + 1, ScanHeight = diff(range(chondro$y)) + 1, ScanOriginX = min(chondro$x), ScanOriginY = min(chondro$y), ScanOriginZ = 0 ) # write asci graph for chondro write.txt.Witec.Graph(chondro, file = "graphascii_chondro.txt", graphname = "chondro", scan_params = scan_params ) # you can now use the data in external software (e.g. ImageLab), # but you can also reimport it again - note that the import function from # {hyperSpec} reads in using pixel units rather than "real world units" # (um in this case) chondro_reimport <- read.txt.Witec.Graph("graphascii_chondro (Header).txt", encoding = "latin1", type = "map" ) # y axis is flipped after reimport - you may correct this chondro_reimport$y <- -chondro_reimport$y # compare original and reimport - note the differing scales # (um in the original, px in the reimport; # in this case 1um is represented by 1px) plotmap(chondro, xlab = "", ylab = "") # real world units used here with # -11.55, -4.77 as the origin and an image size of 35x25um plotmap(chondro_reimport, xlab = "", ylab = "") # not that pixel units are used here with pixel 1,1 being the # origin and an image size of 35x25px }