Showing papers in "Cartographica: The International Journal for Geographic Information and Geovisualization in 1973"

Algorithms for the reduction of the number of points required to represent a digitized line or its caricature

Abstract: All digitizing methods, as a general rule, record lines with far more data than is necessary for accurate graphic reproduction or for computer analysis. Two algorithms to reduce the number of points required to represent the line and, if desired, produce caricatures, are presented and compared with the most promising methods so far suggested. Line reduction will form a major part of automated generalization. Regle generale, les methodes numeriques enregistrent des lignes avec beaucoup plus de donnees qu'il n'est necessaire a la reproduction graphique precise ou a la recherche par ordinateur. L'auteur presente deux algorithmes pour reduire le nombre de points necessaires pour representer la ligne et produire des caricatures si desire, et les compare aux methodes les plus prometteuses suggerees jusqu'ici. La reduction de la ligne constituera une partie importante de la generalisation automatique.

The visual perception of the circle in thematic maps/experimental results

Abstract: The circle is a valuable and useful map symbol. However, traditional and popular methods of designing and using the circle to show quantitative data in thematic maps create erroneous impressions in the minds of map readers in two ways. First, the map reader is unable to discern small variations in circle sizes and second, viewers have difficulties in making quantitatively accurate comparisons of the areas of different size circles. This results in a universal and inherent inaccuracy in the visual perception of relative quantities. These shortcomings can be rectified by employing at all times range-graded circles, varying in size according to an experimentally derived key, and by incorporating within the map an appropriate legend, including as many circle size differences as are found in the map environment. This is true for open, black, or gray circles, regardless of selected variations in base maps. These findings provide guidelines for those who seek to use most effectively circles in thematic maps. Le ...

Some reflections on the subject and method of cartography after the sixth international cartographic conference

Abstract: The author, a leading Soviet academic cartographer, criticizes some ideas which have resulted from the successes of automated cartography and which have been presented at recent international meetings, particularly the narrow conception of cartography as an informational technique independent of geography and the notion of the inherent subjectivity of the perception of cartographic information. He poses a broader and less technical definition of cartography with strong ties to geography, and urges greater understanding by the cartographer of the phenomena that he or she is mapping and strict objectivity in cartographic generalization. L'auteur chef de file parmi les professeurs sovietiques de cartographie, critique certaines idees qui resultent des succes de la cartographie automatique et qui ont ete presentees lors des rencontres internationales recentes, particulierement la conception etroite de la cartographie comme technique d'information independante de la geographie et la notion de subjectivite inhe...

Generalisation and realism within automated cartographic systems

Abstract: The principles and practice of generalisation of cartographic elements in an automated system should not be assumed to be the same as those in manual cartography. Given the present lack of knowledge on what constitutes efficiently perceived graphics, generalisation procedures should now be re-designed as economically as possible in machine terms. Certain types of generalisation are, however, much more easily and usefully achieved than others by computer. These types are described in this text. The relative costs of generalisation and digitising of data at different input scales are also discussed. Les principes et l'application de la generalisation des elements cartographiques dans un systeme automatique ne doivent pas etre consideres comme identiques a ceux que l'on utilise en cartographie manuelle. Etant donne le manque actuel de connaissance sur les graphiques compris de facon efficace, les processus de generalisation devraient maintenant etre concus le plus economiquement possible au point de vue meca...

Analogs between class-interval selection and location-allocation models

Abstract: Significant parallels exist between the problem of locating multiple facilities to serve numerous demand points and the problem of dividing data values into categories for choroplethic mapping. Heuristic techniques developed for solving location-allocation problems can be used to solve the statistical part of the class-interval problem using a variety of objective criteria. Psychophysical research on map perception should attempt to determine measurable properties of a map pattern that are important in increasing visual effectiveness and that can be employed either in objective functions or as constraints for computerized optimization algorithms. Il existe des paralleles significatifs entre le probleme de localisation d'installations multiples pour desservir de nombreux points de demande et le probleme de la division de la valeur de donnees en categories pour la cartographie choroplethe. Les techniques heuristiques developpees pour resoudre des problemes de situation et d'affectation peuvent etre utilisee...

Acadia/the origin of the name and its geographical and historical utilization

Abstract: Acadia is a name that has been used for nearly 400 years in the area of the Maritime Provinces. There is strong evidence that it derives from Archadia (Arcadia), given by Giovanni da Verrazzano in 1524 when he sighted an ideal landscape described in classical literature. Cartographers applied it to a region south of New France. In the early 1600s Sieur de Monts found it to be a useful designation for a new colonization scheme between New France and the Spanish possessions. The Micmac termination – Acadie ('occurrence place') appears to have no bearing on the origin of the choronym. Le choronyme Acadie est utilise depuis pres de 400 ans dans les provinces Maritimes. Selon la plupart des auteurs serieux, le terme Acadie serait indeniablement derive du nom Archadia (Arcadia) utilise en 1524 par Giovanni da Verrazzano pour nommer un paysage bucolique qu'il apercut sur la cote de l'Amerique du Nord. Les cartographes se sont servi de ce nom pour designer line region situee au sud de la Nouvelle-France. Au debut...

The canadian cartographer and the computer / present trends and future challenges

Abstract: This paper examines the implications of the increasing importance of the computer in Canadian cartography. Basic distinction is made between automated cartography and computer mapping. Various Canadian systems are discussed, including those of the Surveys and Mapping Branch and Statistics Canada. A number of issues are considered, including the implications of automation for cartographic employment and education, confidentiality, costs, map perception, maps as planning tools, and issues relating to map types, design, content, presentation and scale. Arguments are made for a conceptual shift in Canadian cartography, and for a reexamination of basic cartographic assumptions. The greatest challenge for Canadian cartography will be the provision of a new conceptual and theoretical framework in response to the technological innovations brought by the advent of computer cartography. L'auteur examine les repercussions que peut avoir sur la cartographie canadienne l'importance croissante des ordinateurs. I1 exist...

The bildkarten of hermann bollmann

Abstract: The representation of surfaces in three-dimensions is a problem that has always intrigued cartographers Early attempts to portray towns and cities in the 16th century used elevation as a technique The oblique, perspective-like view came into use in the latter part of the century, and the method was later improved and enhanced The modern plan is accurate, functional and correct, but perhaps less attractive than these early town plans Herman Bollman has revived cartographic interest in 'bildkarten' through the production of a remarkable series of town plans over a period of nearly 25 years In his brilliant series of plans, Herr Bollman has developed new methods in the production of perspective drawings and combines technique with the understanding of a master craftsman La representation des surfaces en trois dimensions est un probleme qui a toujours intrigue les cartographes Les premieres tentatives de representer des villes au 16e siecle ont utilise l'elevation comme technique La vision oblique, co

The essence and content of the history of cartography and the results of fifty years of work by soviet scholars

Abstract: The author, a senior Russian specialist on the history of cartography, briefly and critically reviews Soviet work in his field. He also discusses the nature of the history of cartography, emphasizing that it encompasses the history of the development of cartographic science, not just the history of the geographical map. L'auteur, un eminent specialiste russe en Histoire de la cartographie, fait une breve retrospect critique des travaux sovietiques dans ce domaine. Il traite aussi de la nature de l'histoire de la cartographie, soulignant qu'elle embrasse l'histoire de l'avancement de la science cartographique, et non seulement l'histoire de la carte geographique.