Cockrell, P R2014-07-312014-07-3119831467-8659https://doi.org/10.1111/j.1467-8659.1983.tb00116.xContour (iso-line) maps are used extensively by the Meteorological Office for both routine and research tasks. The techniques employed in a new FORTRAN subroutine (CMAP) for drawing such maps are described. The algorithm employed is raster based, suited to both scalar and vector processors and inherently device independent. In addition some normally cpu intensive operations such as contour shading, chart masking (eg. with respect togeographical areas) and isometric projections are natural extensions of the method requiring comparatively little cpu time.10.1111/j.1467-8659.1983.tb00116.x35-47