PALSfit spectrum files
Elements of a PALSfit spectrum
1. Spectrum file
- Spectrum file
- Spectrum header
- Spectrum body
A spectrum file is a text file consisting of a number of positron
lifetime spectra (from 1 up to 100 spectra).
The preferred filetype is
A spectrum in a spectrum file must be composed of a 'spectrum header'
line and a 'spectrum body'.
The latter consists of a number of
'channels', each containing a count number.
All spectra in a spectrum file must consist of the same number of
A spectrum file containing several spectra should have each spectrum
terminated by a blank line. 2. Spectrum
The first line of a spectrum will be interpreted as a header to
identify the individual spectrum in the file.
No two headers should be identical. If they are, only the first af
those spectra will be accessible.
If a header is missing, PALSfit will attempt to use the first dataline
(in the body) as the header. 3. Spectrum body
This will only work if the spectrum file
contains one single spectrum.
The spectrum body contains the actual counts in a proper format
suitable for collective reading.
There is in principle no limit to the number of channels. The program has been verified up to 64,000 channels pr. spectrum.
PALSfit allows spectrum lines to be up to 260 characters in width, but
we recommend a maximum of 80 characters pr. line.
Each line (except the first and last) in the spectrum body must contain
the same number of channels.
If the first line has fewer numbers than the following, then it will be
skipped when reading the spectrum.
This allows for storing extra
descriptive data, which will be neglected by PALSfit.
The preferred format of a data line is n columns of right aligned
PALSfit will however accept lines containing n numbers separated by a
fixed delimiter, either comma or tabulation, as long as the same delimiter
is used in all spectra in the file.
If the last line in a spectrum is shorter, only by containing fewer
channels, but otherwise formatted like the rest, then these channels will
be included in the spectrum and included in the channel count, otherwise
they will be skipped.