carlvlewis / ggd3

GGD3

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Grammar of graphics in D3.js

Roadmap:

• Fixed/free space
• Pan and zoom on x and y axes.
• Brush on one axis or both axes
  • Scatterplot highlights according to datapoint value or id
• Context brush for either axis, [linear, ordinal, or time]
• All global aesthetics (fill, color, alpha, size) are aggregated according to the facet and groupings, and the median is calculated if it is numeric. If it is a factor and it was a grouping variable (fill, color, group), the first observation of the array is taken, because the will all be the same. If it was not a grouping variable (fill and color may not be), it is calculated. Other calculations are available. Min, max, mean, percentile.
• tooltip displays all known data for given point.
• Initial geoms:
  • geom bar with stack, group and expand options
  • point w/ jitter on ordinal axis
  • line, hline, vline, abline
  • box
  • geom error that mounts on geom point, bar, box, line, etc.
  • smooth with loess or lm methods
• Possible adoption of bin-summarize-smooth methods to replace plots that draw too many DOM elements.
• Sampling methods for large datasets

Problems and questions:

• Find smarter way to decide, during computation step, which axis is the number and which the factor. Currently my dtypes function returns a two tuple
  • the first is one of "number", "string", or "date"
  • the second is one of "few" or "many", 20 being the cutoff
  • if it's a date, a third element can be the format to be passed to axes.
  • doing it like this prohibits drawing 100 boxplots on a single facet
• Introducing several layers and allowing them to map different variable names tto the same aesthetic confuses me. If layer 0 maps "foo" to 'fill' and layer 1 maps 'bar' to 'fill', do I go through both and create a fill scale based on the union? I say layer one is special and should contain all relevant catagorical scale info. Subsequent layers can expand numeric domains, only.
• The more I do, the more the "layer" element seems to be important in theory only. As such, layer-specific features such as position, aesthetics, and even data, should be able to be set directly on the geom.