Connecting lines through null values, and date values on x-axis

BS,

The Scatter Chart is broken with Date X-Values. Submit Feedback from the Numbers menu and ask for it to be fixed. For now, use Numbers 2.3.

Jerry

As I'm sure you know, if your Dates are a regular series, you could use a Line chart instead of a Scatter Chart.

Jerry

1) I've created a scatter chart with date values along the x-axis and three columns of data along the y-axis. Some of the data values are missing, yet I'd still like to connect the points, from the first data point through to the last without a break in the line.

Is there a way to connect lines through null values?

Hi Badsushi,

There doesn't appear to be a way to "connect" through the null values. (That makes sense to me because how would Numbers know what to connect to?)

But you can run trendlines in various ways even when some values in a series are null:

SG

I could write a formula to calculate the mid-point between those two data values for the purposes of the chart, but it wouldn't accurately represent the data.

Why would that less accurately represent the data than other apps, which are doing the same thing for you?

SG

I see. There are workarounds but probably not worth the trouble for large datasets. I suggest in your menu you go to Numbers > Provide Numbers Feedback and mention this use case. Here's what I get in Excel, though, before applying trendlines.

I've seen Wayne recommend a program called DataGraph here in the discussons. I had a look at the trial and it looks as if it can handle just about anything.

SG

I'm having a similar problem. In this case, because the scatter plot wasn't working I forced the x-axis to follow a regular series (even though this was slightly off), allowing me to use a line graph. But I'm astonished that even now I can't seem to find a way to connect lines through the null values.

This seems incredibly elementary, and I'm hoping it's a bug and not yet another design oversight on the part of the Numbers team. (Is there a "team" or is Numbers someone's side project?)

Your comment about using a line graph gives me hope that perhaps it's pilot error, in which case could you please let me know what I'm doing wrong?

What's even worse, it looks like if I switch to a polynomial trendline to approximate line connections between three or more points, it wipes out the lines connecting only two points.

My only alternative, I think, is to interpolate a value in the case of only two values to force the polynomial trendline to work?

Why not make a table that does not share the x value so thay you can enter only the (X, Y) pairs where both have a value?:

The chart on the left enters data the way the OP did (a common, shared) x-axis. switch to non-shared x-axis (chart on the right) and your problems are fixed.

Thank you, thank you, thank you. That worked perfectly, once I went back to 2.3.

3.0.1 has at least two bugs or design regressions that prevent this from working:

1. The date/time x-axis isn't available
2. I can't find a way -- whether it's drag-and-drop; control-click then select; or command select -- to add another data series that includes an X value.

What I'm trying to do, incidentally, is simply track swimmers' event times over a period of a year or so. The meets are shared and on a regular basis (i.e., on weekends, though not every one), but not every swimmer competes at a given event in every meet.