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Basic Data Displays

We begin with the familiar two dimensional point cloud. Point cloud layout is the positioning of each constituent point symbol according to values for the x and y variates. Positioning is carried out in the coordinate system of the variates themselves. When the point cloud is drawn, the point symbol locations in variate coordinates are transformed into viewport locations in screen coordinates. Thereafter we describe layouts where views are positioned within a bounding region in some abstract coordinate system.

Views such as the 2d-pointcloud that require two values per case are collectively known as 2-d views. Other examples of 2-d views are the lines-view, which has line segments connecting consecutive pairs of coordinates, ordered by the x values, the fitted-line, which uses the coordinates to compute a (by default, least squares) fitted line, and a smooth. Similarly, views such as a histogram-view and a boxplot-view, which use one coordinate per case are collectively known as 1-d views and a rotating-point-cloud is a 3-d view. In summary, a p-d view is a view that given a dataset and p variates, calculates p values per case.


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Next: Plot Layout Up: ORGANISING INFORMATION GRAPHICALLY Previous: ORGANISING INFORMATION GRAPHICALLY

2000-01-28