xBit64 v2.03 README. April 10, 1995 ================================================= xBit64.sit.hqx contains: ----------------- "xBit64": FAT IgorPro XOP file. Provides 10 new external functions (XFUNCs) to IgorPro running on PPC or 68k Macintoshes. "macros-Bit64": Procedure file. Provide a few handy macros extending the usefulness of the external functions. "macros-Bit64 Demo Panel": Demonstration procedure file. "Bit64 Tutorial": IgorPro Notebook file. Step-by-step introduction to the functions. ================================================ FUNCTIONS: --------- The functions provided by xBit64 give IgorPro programmers bitwise access to 64-bit, double precision variables and wave elements. They provide the following single bit operations: SET CLEAR TEST They provide the following bitwise operations on 64-bit masks: AND OR EXCLUSIVE OR DIFFERENCE SET INCLUSION SET EQUALITY COMPLEMENT ================================================= PURPOSE: -------- We developed these functions in order to manage a number of "flags" applied to large data sets. Specifically, we collect chromatographic data. For each sample, there are a number of compounds which may be detected. Using xBit64, we can assign one flag to each compound. Thus, if the "CFC-113" flag is set for a given sample, we know that we obtained a good value for that compound. Other flags tell us the source of each sample, "Calibration", "Air", "Zero Air", etc... Yet others store the state of certain instrument solenoid valves at sample time. In post-processing, the flag wave becomes a data filter. Using the "set inclusion" operation, for instance, the analyst can request all samples of "Air" which contained bad "CFC-113" data, and then look for sources of trouble. ===================================================== By: Tom Baring tbaring@cmdl.noaa.gov Contributed free of charge. No warranty. You accept all risk in using this software.