The LEXIS Program for Creating Shaded Contour Maps of Demographic Surfaces

The LEXIS computer program, which was developed at the International Institute for Applied Systems Analysis (IIASA) and Duke University, is intended to aid demographers in the analysis of large arrays of data. Its application as a supplement t o other methods of graphic display is demonstrated in 'Thousands of Data at a Glance: Shaded Contour Maps of Demographic Surfaces" (Vaupel, Gambill, and Yashin, 1985) and will not be discussed here. This paper provides instructions on the use of the program, gives some hints concerning the art and craft of using the program in a creative way, and briefly describes the algorithm used in designing the program. A diskette containing a copy of the LEXIS program may be obtained from the authors or from IIASA. The program is copyrighted but the diskette is not protected against copying: please feel free to make and distribute copies. By making the program available to demographers and others interested in mapping the contours of surfaces, we hope to encourage the development of this method of data analysis. We would, of course, sincerely appreciate it if we and the International Institute for Applied Systems Analysis were acknowledged when the program or some modified version of it is used to produce maps for presentation or publication. Comments and suggestions are welcome

Contour Maps of Population Surfaces

Contour maps are useful for displaying demographic surfaces, including surfaces of population levels and fertility, marriage, and mortality rates. Most often the surfaces are defined over age and time, but such other dimensions can be used as life expectancy or population growth rate. This paper presents a bouquet of contour maps to suggest the broad potential of their use in demographic studies. The maps presented range from maps of Italian mortality, French population levels, and U.S. birth rates, to maps of Coale and Demeny's and Brass's model life tables. The value of the maps lies in their substantive import: by giving demographers visual access to population surfaces, the maps can help demographers uncover and understand population patterns. The text of the paper adumbrates some of these patterns and discusses the use of contour maps in exploratory data analyses and model building, including the use of maps of residuals in fitting models to data

The LEXIS Computer Program for Creating Shaded Contour Maps of Demographic Surfaces

The LEXIS computer program, which was developed at the International Institute for Applied Systems Analysis (IIASA) and Duke University, is intended to aid demographers in the analysis of large arrays of data. Its application as a supplement t o other methods of graphic display is demonstrated in Thousands of Data at a GLance: Shaded Contour Maps of PopuLation Surfaces (Vaupel. Gambill, and Yashin, forthcoming) and will not be discussed here. This paper provides instructions on the use of the program, gives some hints concerning the art and craft of using the program in a creative way, and briefly describes the algorithm used in designing the program. A diskette containing a copy of the LEXIS program is enclosed. The program is copyrighted but the diskette is not protected against copying: please feel free to make and distribute copies. By making the program available to demographers and others interested in mapping the contours of surfaces, we hope to encourage the development of this method of data analysis. We would, of course, sincerely appreciate it if we and the International Institute for Applied Systems Analysis were acknowledged when the program or some modified version of it is used to produce maps for presentation or publication. Comments and suggestions are welcome

Contour Maps of Demographic Surfaces

This paper presents a bouquet of contour maps to suggest the broad potential of their use in demographic studies. Every picture presented could serve as the basis for a thousand words or more of explanation and analysis, but here we merely serve up the maps as illustrations of the method. For an example of how such maps can be used in demographic analysis, see Caselli, Vaupel, and Yashin (1985): Mortality in Italy--Contours of a Century of Evolution (CP-85-24, International Institute for Applied Systems Analysis, Laxenburg, Austria)

Cause Specific Mortality in Japan: Contour Maps Approach

An important part of the activity of IIASA's Population Program is related to the development of data visualization techniques. The paper is devoted to the analysis of cause specific mortality data for Japan using the shaded contour map approach which was recently developed in the program by an international team of scientists

Thousands of Data at a Glance: Shaded Contour Maps of Demographic Surfaces

Contour maps are useful for displaying demographic surfaces, including surfaces of population levels and fertility, marriage, and mortality rates. Most often the surfaces are defined over age and time, but other dimensions can be used such as life expectancy or population growth rate. This research report presents a bouquet of contour maps to suggest the broad potential of their use in demographic studies. The maps presented range from maps of Italian mortality, French population levels, and US birth rates, to maps of Coale and Demeny's and Brass's model life tables. The value of the maps lies in their substantive import: by giving demographers visual access to population surfaces, the maps can help demographers uncover and understand population patterns. The text of the research report adumbrates some of these patterns and discusses the use of contour maps in exploratory data analyses and model building, including the use of maps of residuals in fitting models to data