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SPECTRUM is designed for post-run (rather than real-time) processing of "spectral" or time- series data (y values at equally-spaced x intervals), such as spectra, chromatograms, electrochemical signals, etc. The program enhances the information content of instrument signals, for example by reducing noise, improving resolution, compensating for instrumental artifacts, testing hypotheses, and decomposing a complex signal into its component parts.
SPECTRUM was the winner of two EDUCOM/NCRIPTAL national software awards in 1990, for Best Chemistry software and for Best Design.
Machine Requirements: SPECTRUM runs only on older Macintosh models running OS 7 or 8, minimum 1 MByte RAM, any standard printer. Color screen desirable. SPECTRUM has been tested on most Macintosh models and on all versions of the operating system through OS 8.1. No PC version or more recent Mac version is available or planned, but if you have some older model Macs laying around, you might find this program useful. SPECTRUM was written in Borland's Turbo Pascal in 1989. That firm has long been out of business, neither the Turbo Pascal complier nor the executable code generated by that compiler runs on current Macs, and therefore there is no way for me to update SPECTRUM without completely re-writing it in another language.
The full version of SPECTRUM 1.1 is available as freeware, and can be downloaded from http://www.wam.umd.edu/~toh/spectrum/. There are two versions:
SPECTRUM 1.1e: Signals are stored internally as extended-precision real variables and there is a limit of 1024 points per signal. This version performs all its calculations in extended precision and thus has the best dynamic range and the smallest numeric round-off errors. The download address of this version in HQX format is http://www.wam.umd.edu/~toh/spectrum/SPECTRUM11e.hqx.
SPECTRUM 1.1b: Signals are stored internally as single-precision real variables and there is a limit of 4000 points per signal. This version is less precise in its calculations (has more numerical round-off error) than the other version, but allows signals with data more points. The download address of this version in HQX format is http://www.wam.umd.edu/~toh/spectrum/SPECTRUM11b.hqx.
The two versions are otherwise identical.
There is also a documentation package (located at http://www.wam.umd.edu/~toh/spectrum/SPECTRUMdemo.hqx) consisting of:
1. Reference manual. Macwrite format (Can be opened from within MacWrite, Microsoft Word, ClarisWorks, WriteNow, and most other full-featured Macintosh word processors). Explains each menu selection and describes the algorithms and mathematical formulae for each operation. The SPECTRUM Reference Manual is also available separately in PDF format at http://www.wam.umd.edu/~toh/spectrum/SPECTRUMReferenceManual.pdf.
2. Signal processing tutorial. Macwrite format (Can be opened from within MacWrite, Microsoft Word, ClarisWorks, WriteNow, and most other full-featured Macintosh word processors). Self-guided tutorial on the applications of signal processing in analytical chemistry. This tutorial is also available on the Web at (http://www.wam.umd.edu/~toh/Chem498C/SignalProcessing.html)
3. Tutorial signals: A library of pre-recorded data files for use with the signal processing tutorial. These are plain decimal ascii (tab-delimited) data files.
(c) 1989 T. C. O'Haver. This program is free and may be freely distributed. It may be included on CD-ROM collections or other archives.
T. C. O'Haver
Dept. of Chemistry and Biochemistry
University of Maryland
College Park, MD 20742
Last updated March, 2012.
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