This documentation is divided into three parts: Instructions for DOS users David Cummins cummins@stat.ncsu.edu *********** FOR DOS USERS *********** I am including a file called DECOMP.EXE. This is the dos equivalent to the unix uncompress command. Also, the file COMPRESS.EXE is equivalent to the unix compress command. So you can download compressed files to a dos machine, and uncompress them there. Remember if you want to download the sp500.dat file to a dos machine, you need to use the unix2dos utility so that it will have the proper carriage control at the end of each line. uncompress it, convert it to dos format, then compress that file, then download it (use binary setting) to your dos machine, then decompress it using the dos decomp utility. SCATTER.EXE I am also including a program to make scatter plots from an input data file. Since the s&p file has over 16,000 records, it may not be possible to import it into your spreadsheet and graph it from there. This program can handle any size file, because it doesn't store its arrays in memory. The program itself teaches you how to use it, but for the sp500.dat file, if you wanted to graph the S&P index over time, you would notice that it is the sixth column in the file, and also that you don't want to graph the first two lines since they are header info, and you would enter the following: scatter sp500.dat 6 6 startrec=3 endrec=99999 at the dos prompt, in the directory where the sp500.dat file resides. The first 6 is the x axis, and the second 6 is the y axis. If you make the x and y the same, the program knows to map the y column against time. If you wanted to graph the index against volume, you could enter scatter sp500.dat 8 6, which would graph volume on the x axis and the index on the y axis. (not a pretty graph!)