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Activity Number:
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254
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Type:
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Contributed
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Date/Time:
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Tuesday, August 5, 2003 : 12:00 PM to 1:50 PM
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Sponsor:
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Section on Statistical Graphics
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| Abstract - #300111 |
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Title:
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Density Distribution Sunflower Plots
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Author(s):
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William D. Dupont*+ and W. Dale Plummer
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Companies:
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Vanderbilt University School of Medicine and Vanderbilt University School of Medicine
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Address:
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Division of Biostatistics, Nashville, TN, 37232-2158,
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Keywords:
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scatter plot ; bivariate data ; density plot ; graphical statistics ; sunflower
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Abstract:
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Density distribution sunflower plots are used to display high-density bivariate data. They are useful for data where a conventional scatter plot is difficult to read due to overstriking of the plot symbol. The user subdivides the x-y plane into a lattice of regular hexagonal bins of width w. She also specifies the values of L, D and k that affect the plot as follows: Individual observations are plotted when there are less than L observations per bin as in a conventional scatter plot. Each bin with from L to D observations contains a light sunflower. Other bins contain dark sunflowers. In a light sunflower each petal represents one observation. In a dark sunflower, each petal represents k observations. The user can control the sizes and colors of the sunflowers. By selecting appropriate colors and sizes for the light and dark sunflowers, plots can be obtained that give both the overall sense of the data density distribution as well as the number of data points in any given region. A documented Stata program that draws these graphs is available (see www.jstatsoft.org/index.php?vol=8).
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