Consider a spreadsheet for monitoring blood pressure. It has three columns: date, systolic pressure, and diastolic pressure. Each day, a new row is added. There's also a "Line with Markers" chart that plots the two measurements over time.

If I fail to record a measurement on a given day, the chart does the intuitive thing: The X axis steps consistently through time, but there are no markers on the days there are no measurements.

Suppose, though, I fail to record just one of the measurements. On a particular row I have the date and the systolic pressure but a blank cell for the diastolic pressure. The chart will show the diastolic pressure dropping to 0 on that day.

How do I get the chart to omit individual missing values rather than treating them as zero?

Consider a spreadsheet for monitoring blood pressure. It has three columns: date, systolic pressure, and diastolic pressure. Each day, a new row is added. There's also a "Line with Markers" chart that plots the two measurements over time.

If I fail to record a measurement on a given day, the chart does the intuitive thing: The X axis steps consistently through time, but there are no markers on the days there are no measurements.

Suppose, though, I fail to record just one of the measurements. On a particular row I have the date and the systolic pressure but a blank cell for the diastolic pressure. The chart will show the diastolic pressure dropping to 0 on that day.

How do I get the chart to omit individual missing values rather than treating them as zero?

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