kcui23

Time Series Visualization (I)

Basic tasks and visual strategies for temporal data

Befor beginning

• Be careful of variation across datasets and variation across tasks
• Based on that, there have been several efforts to systematically taxonomize the types of queries that time series visualizations have been used for.
• 

Technical details

• Human eyes good at catching information of lines: use geom_line() to create basic lines
• It is useful to draw area plot to emphasize the fact that these are amounts (they must be nonnegative). e.g. trade volume: use geom_area() to create area plot
• For a larger collection of time series: use group_by() and facet_wrap() or facet_grid() to create plots at the same time

kcui23

Small Multiples and Faceting

Motivation:

• want to show more variables or dimensions at the same time

Technical Details

• we can use facet_grid or facet_wrap to do that
• you can use different types of figure like scatterplot, line, barplot
you can use scale = “free_y” in facet function to allow different scales in different raws