Welcome to Semi-Sentient Systems (R) GraphDigitizer 1.0! ----------------------------------------------------------------------- This file contais a brief description of GraphDigitizer. For complete information please refer to GRAPHDIG.HLP. To read GRAPHDIG.HLP, double- click on it in Microsoft Windows File Manager or run WINHELP.EXE and use File|Open menu to open GRAPHDIG.HLP. ----------------------------------------------------------------------- Overview. --------- Have you ever needed to convert a graph printed on paper back into the digital data used to create the graph? Suppose you want to utilize someone else's results in your research and need the raw numbers for calculations. Or you are going to use your old graph in a new article but feel it's necessary to change the scale, data symbols, or add new curves -- and -- oops! -- can't find the file with the data from which the graph was produced. What would you do in such a situation? The answer is obvious: take a ruler or piece of graph paper, a calculator, and pencil and start working. If there is an expensive graph tablet with sophisticated software at hand, which is usually not the case, it could save you the boring chore of calculating each data point's coordinates. Wouldn't it be nice to employ something more common than graph tablets to automate the job? What about a scanner or xerox? Unlike graph tablets with special software, scanners and xeroxes are not uncommon gadgets in an average office or laboratory, and it's not necessary to spend hours reading manuals to use them. If you have a PC that runs Microsoft Windows 3.1 or later, GraphDigitizer makes it possible to convert graphs with the help of a scanner or xerox, or just an overhead projector transparency and a marker, into numerical data of great precision. Here is the idea behind GraphDigitizer: the graph to be digitized is projected onto the computer screen in one or another way and the data points are marked directly on the screen with a pointing device, such as a mouse. GraphDigitizer computes the real coordinates of each marked point corresponding to the original graph's coordinate system and writes them in a file format that can be read later by a spreadsheet or chart- drawing application, such as Microsoft Excel or Microsoft Graph, or directly by a user. To project the image on screen, the following three methods may be used: 1) The graph is scanned and written into a file. GraphDigitizer reads the file containing the scanned image and displays it onscreen as a background. This is the most accurate method. Of course, scanning the image takes some time. However, this will be compensated by easier, faster, and more accurate digitizing. 2) The image is xeroxed onto a transparency, then laid over the computer screen. Then GraphDigitizer's window is then resized and positioned to fit the graph. This is a quick and dirty method that works fine, if high accuracy is not important. 3) The image is copied onto a transparency with a marker rather than a xerox. This is, of course, the quickest and dirtiest method of the three. Installation. ------------- GraphDigitizer will work on any PC running Microsoft Windows 3.1 or later, or Windows NT 3.5 or later. Mouse or other compatible pointing device is necessary. Math coprocessor is very desirable. To install GraphDigitizer, create a directory on your hard drive, copy GRAPHDIG.ZIP over, then unzip it with PKUNZIP or any other PKZIP- compatible utility. You should hopefully see the following nine files listed in the directory: 1) GRAPHDIG.EXE -- 32-bit version of the executable file, 2) GRAPHD16.EXE -- 16-bit version of the executable file, 3) GRAPHDIG.HLP -- help file, 4) README.TXT -- this file (short overview, ASCII text), 5) CTL3DV2.D~~ -- Microsoft 3-D Controls DLL (16-bit), 6) CTL3D32.D~~ -- Microsoft 3-D Controls DLL (32-bit), 7) SAMPLE.BMP -- sample scanned image in Windows 3.0 Bitmap format, 8) SAMPLE.DAT -- sample data file, 9) SAMPLE.CSV -- sample data file in CSV format. In Windows Program Manager, create a new program group (or choose an appropriate existing one) and create a new program item "GraphDigitizer" in that group. If you are running Microsoft Windows NT or Windows 3.1 with Win32 installed, the command-line will be DRIVE:\DIRECTORY\GRAPHDIG.EXE, where DRIVE:\DIRECTORY stands for the name of the drive and directory where GraphDigitizer's files are put. Otherwise, the command-line should be DRIVE:\DIRECTORY\GRAPHD16.EXE. GRAPHDIG.EXE and GRAPHD16.EXE are completely independent of each other and functionally equivalent, although, being a 32-bit application, GRAPHDIG.EXE is much faster. I promise, it will run under Windows 95 as well, should Microsoft finally come up with it (hopefully we will see it happen in this century). When you run GraphDigitizer for the first time, it will try to install CTL3DV2.DLL (16-bit) or CTL3D32.DLL (32-bit) in WINDOWS\SYSTEM directory, if these files are not already there. If you run Windows via a network, WINDOWS\SYSTEM directory may not be available for writing. If for some reason the above-mentioned DLLs cannot be installed properly, GraphDigitizer will complain and advise you how to solve the problem. Neither CTL3DV2.D~~ , nor CTL3D32.D~~ should ever be renamed or moved to a directory other than the one containing GRAPHDIG.EXE and GRAPHD16.EXE.