fprintf behaviour

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I use IGOR to group and sort EDS spectra (counts vs. energy) which I then want to export and quantify in external software. The latter needs to read a header from a spectrum to identify instrument settings. I load this header from an existing spectrum and store it as a global string variable. The string header may look like this (print header):

•print header
#FORMAT : EMSA/MAS Spectral Data File
#VERSION : 1.0
#TITLE : Base(1)
#DATE : 20-SEP-2013
#TIME : 13:55: 6
#OWNER :
#NPOINTS : 2048
#NCOLUMNS : 1
#XUNITS : keV
#YUNITS : Intensity
#DATATYPE : XY
#XPERCHAN : 0.010000000
#OFFSET : 0.000000000
#CHOFFSET : 0.000000
#SIGNALTYPE : EDS
#XLABEL : X-Ray Energy
#YLABEL : X-Ray Intensity
#BEAMKV -kV: 15.0
#EMISSION -uA: 0.0000
#PROBECUR -nA: 1.0000
#BEAMDIAM -nm: 0.0
#MAGCAM : 0.0
#OPERMODE : IMAG
.
. //more lines to follow

.
#SPECTRUM :

After the last entry "#SPECTRUM :" the actual data would follow. The header in this particular case contains about 540 entries (lines). My export function looks like:

function ExportSpectrum(header, spectrum)
    string header
    wave spectrum
   
    Variable refnum
   
    string filename = NameOfWave(spectrum)
   
    Duplicate/O/Free  spectrum Energy
    Energy = x
   
    Open/Z=2 /P = SpectrumPath /T="emsa"  refnum   as FileName+".emsa"          // path exists from loading header
   
    if (V_flag == -1)   //User cancelled dialog
        return -1
    endif
   
    fprintf refnum, Header                                          // writes header file to file, followed by return
    wfprintf refnum, "%g, %12d,\r\n",  Energy, spectrum         // writes energy and count data to file, followed by return
    fprintf refnum, "#ENDOFDATA   : \r\n"
    Close refnum
   
    return 1
end


The problem is that fprintf refnum header does not write the header completely to file (same for fprintf 1 header and the history window) but a large portion of the string is missing. Would that be for some reason an expected behaviour?
I would not be shocked to discover that fprintf is printing into a fixed-sized buffer. Try printing the header using Fbinwrite then print the remainder with a separate fprintf call.
--Jim Prouty
Software Engineer, WaveMetrics, Inc.

September 21, 2013 at 06:17 pm - Permalink

Thanks!
FBinWrite worked but in the end I changed my header load procedure that now creates a header text wave instead of a string.

September 22, 2013 at 06:20 am - Permalink