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Contents → Standard User Functions → scans.4 → File conventions

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The scan files contain control lines, data lines and blank lines. Control lines contain a # character in the first column followed by a command word. Data lines generally contain a row of numbers. Special data lines containing MCA data begin with an @ character followed by a row of numbers. These data lines are ignored unless the use MCA data option .B +M is selected.

The control conventions used by scans.4 are as follows:

#S N

3m starts a new scan. Here, N is the user's numbering scheme and is the number used when retrieving by scan number (+S). Most often the scan number is the position of the scan in the file.

#M N

3m indicates data was taken counting to N monitor counts.

#T N

3m indicates data was taken counting for N seconds.

#N N [M]

3m indicates there are N columns of data. If M is present, it indicates there are M sets of data columns on each line. When collecting data from a multi-channel analyzer, for example, the data might be arranged with 16 points per line in the file to make the file easier to scan by eye. In such a case, the control line would be #N 1 16.

#I N

3m is for an optional multiplicative intensity-normalization factor.

#@MCA

3m indicates the scan contains MCA data. If the +M option is selected, x (2D or 3D) or y (3D only) values will be calculated automatically. In three-column mode, whether it is x or y depends on whether the x=M or y=M command line option is selected or on which interactive response was given. Data in the lines starting with @A will be stuffed into the y (2D) or z (3D) data array.

#@CALIB a b c

3m gives calibration factors for MCA data. The x (2D or 3D) or y (3D only) values will be calculated using the formula

xi = a + b*i + c*i*i

where i is the point number, starting from zero. Calibration factors can be changed within the data portion of a scan for subsequent MCA data by the line

@CALIB a b c

Before each scan is read by scans.4, the calibration parameters are initialized to zero.

The following control lines are not commands but are printed out as they are encountered while reading a scan:

#C

3m is a comment line.

#D

3m is followed by the date and time the scan was taken.

#L label1 label2 ...

3m is the data-column labels, with each label separated from the next by two spaces.

For example, a very simple file might have:

#S 1
#N 3
#L Temperature  Voltage  Counts
23.4 1.01 30456
23.6 1.015 24000

#S 2 etc.

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