Contour Maps and Three-Dimensional Representations with a Line Printer Pseudo-three-dimensional diagrams from digital XY-plotters, and descriptions of their use; have been publishedl.2 and find wide acceptance for their clear representation of complicated functions. However, the digital blotter may be slowand expensive to use or may not he available a t all institutions. Therefore, a computer program has been written to provide such three-dimensional representations on a line printer, as well as two-dimensional contour diagrams. The Fortran IV program PRINT (acronym for Plotting, and Repiesentation IN Three dimensions, by PRINTer) evaluates and plots, on the digital line printer, a user-defined function of u p to thtee independent parameters, according t o one or mare of the following -o.~ t i o n s (1) a two-dimensional contour map of the defined function, undistorted dimensionally (to within one line space) (2) pseudo-three-dimensional views of the function, evaluated across a two-parameter section (specified as the XY section) a t selected azimuths and elevations of view, with "hidden" contours omitted (3) further three-dimensional views of XYsections of the function a t a series of values of a third (Z) parameter Although the three parameters are denatedx, Yand 2,there is, of course, no requirement that they be spatial parameters. The program PRINT, together with complete user instructions, is available from the Quantum Chemistry Program Exchange3 a s Program QCPE 219. IBordass, W. T., and Linnett, J. W., J. CHEM. EDUC., 47,672 (1970). 2Deming, S. N.,Anal. Chem., 43,1726 (1971). Quantum Chemistry Program Exchange, Chemistry Dept., Room 204, Indiana University, Bloamingtan, Ind., 47401. Rhodes University Grahamstawn, South Africa
L. Glasser
Volume 50. Number 6, June 1973 / 421
