The Felix New Format

The Felix New Format data header parameters.

Some customers have asked for more information about the Felix New Format data header. A Felix New Format data file consists of a pre-header(byte key), a header, and then one or more spectra. The header itself consists of some initial general information about the file followed by one or more frames which contain spectral parameters.

The first word of a Felix New Format data file contains the byte key. The second word contains the number of words in the header. This is often 256 for example. The next 256 words contain the header information. The first 5 words of the header (words 1 to 5) contain the Number of Frames (1), Data Format (floating point), Frame Size (32 words), an unused parameter (default=1) and the Felix Version Number. The actual spectrum specific information is stored in the header frames. Currently only one header frame is actually used but the original idea was that multiple frames could be used to store the information for the various dimensions in a multidimensional experiment for example. Thus the Frame Size parameter is the size of the header frames. This should be left at the default of 32 words. The Number of Frames parameter is the number of these header frames that are contained within the header. This should be left at the default of one header frame. Note then that only one header frame will be present and it will be located at words 95 to 126. This is where the actual header information will be found. The rest of the header will generally just contain a series of integers which will indicate the corresponding point number in the header that the number corresponds to. Thus point number 127 in the header will contain the integer value of 127 etc. After the 256 header values then the data records will start. The first number in the data record is an integer which indicates the number of words in the data record. The actual floating point data values will follow this number. Multiple data records may be present for multidimensional data.

For more information about this see Table 24. Felix Data File Formats in The Felix Data Format section of Appendix D. Data Transfer and Conversion of the Felix User Guide.