Raw scans 20001 to 20200 are stored within the
second file on a magnetic tape containing 4 files.
The following sequence of SPA commands will
read the data into the S file subdirectory S12, reduce the data by
selecting a backend spectrometer within the observed configuration,
put the x axis of the spectra into the velocity domain,
remove a first order baseline within the velocity intervals
-15 to 2 km s 
and 10 to 27 km s , calculate
moments within the velocity interval 4 and 8 km s-1 and place the
results in S13.
One must first check the status of the data files with the files command. S12> files The program list the various files: Command Input (A,B,TY,CR) = A Command Responses (A,B,PR,TY,VP,NP) = A Printer (A,B,PR,TY,VP,MT,DI,NO) = A Plotter (A,B,TY,VP,MT,NO,HP) = A Tape file (MT, MT01 - MT04) = MT01 Tape mode(0=SEQUENCE, 1=SCAN) = 1 To change the tape file to the second file on tape while leaving the remaining files unchanged, ,,,,mt02
One must now mount the tape with the TAPE command. S12> tape The program now prompts the user for answers to a series of questions concerning the magnetic tape. DO YOU WANT TO LIST THE CURRENT FILE? YES OR NO no DO YOU WANT TO ADD TO COMMENTS? YES OR NO no DO YOU WANT TO WRITE A DIRECTORY? YES OR NO no DO YOU WANT TO MOUNT A NEW TAPE? YES OR NO yes NOW MOUNT A NEW TAPE. IS IT READY? yes The program reads and prints the tape directory and moves the tape to the beginning of the first tape file. DO YOU WANT TO ERASE ANY FILES? YES OR NO no
Now read the data into the S12 subdirectory. S12> s12 = 20001 to 20200 read
To reduce the raw data, one needs to modify the baseline and line functions constants which can be done on the command line. S12> s13 = s12 first vlsr base ? line ?
For the first scan, the program stops to list the function constants for the baseline function, ORDER OF POLYNOMIAL=1 XL1=-1.0E+35, XU1=1.0E+35 XL2=-1.0E+35, XU2=1.0E+35 XL3=-1.0E+35, XU3=1.0E+35 The user then enters the desired baseline parameters. 1,-15,2,10,27 A baseline will be removed from the first pixel of the first scan and some information regarding the polynomial and calculated rms is printed. The program stops again to list the constants of the line function XL=-1.0E+35, XU=1.0E+35 The user enters 4,8
The program now processes all pixels within all scans and writes the results to S13. without further input from the user