Needle Graphs: Display Time-Based Transaction Data
Needle Graphs display time based transactions or occurrence frequency, rather than time based trends. They are simply time based Bar Graphs where each bar is located at a particular time point on the axis. They work especially well when combined with a Line Graph. Needle Graphs are commonly used to display trading volume for a stock, commodity or other financial instrument, usually underneath a Line Graph correlated to price performance.
Numeric Needle Graphs display price distributions
Numeric Needle Graphs specialize in displaying price distributions. The X Axis is referenced to an arbitrary series of numbers instead of time. Like traditional Needle Graphs, they are simply a special kind of Bar Graph, but each bar in a Numeric Needle Graph is associated with a particular number in the numeric series used to generate the X Axis and their height is determined by their Y values. This allows gaps and clustering in price to be more accurately identified. They work especially well when combined with a Numeric Line Graph visualization.
Stacked Needle Graph visualizations
Stacked Needle Graphs display time based transactions or occurrence frequency and are quite similar to the standard Needle Graph. However, Stacked Needle Graphs allow each transaction to be split into its components, which makes it easy to see contribution to the total across time. Common uses for the Stacked Need Graph include the split of transaction volume by venue or by direction (Buy versus Sell).