There has been a lot of discussion here lately about XY and Line charts:
- Line Charts vs. XY Charts
- Line-XY Combination Charts
- Category Axis Tricks for Line and Area Charts – 1
- Category Axis Tricks for Line and Area Charts – 2
- Order of Points in XY and Line Charts
Many of these posts have described differences between XY and Line charts. One difference that’s been mentioned but not examined is that an XY axis recognizes the complete numerical value of its X data, while a line chart only recognizes whole number (integer) categories. Even if you use a Date-Scale X axis in a line chart, the dates are treated as categories, and you can only plot a point on a date, not on a time between midnight and midnight.
To investigate the behavior further, let’s look at fractional data, that is, dates with times. This data set contains a few points per day (midnight, noon, 6pm; not uniformly spaced) over several days. [Read more…] about Integer Values on Line Chart Category Axis