Can you create a line chart with fixed reference lines?

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Level 1

10 points

Can you create a line chart with fixed reference lines?

I want to create a simple chart that tracks my blood pressure. It's straight-forward to enter readings into a table and create a line graph based on the observations. What I would like to do though is to have a a fixed horizontal reference line that marks the "normal" threshold so I can easily see when the chart goes above and below the threshold line. There doesn't seem to be a built-in way to do it so I thought maybe I would get fancy and add a data series that was basically a static fixed number to a new, hidden table. What happened when I did this though it only adds one data point at the beginning and I can't get it to make a line unless I create a new copy of the threshold value for each observation. Any ideas?

Posted on Mar 31, 2014 1:18 PM

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Answer 1

Mar 31, 2014 3:17 PM in response to Tom Roehl

Tom,

Use the Scatter Chart option and make your reference line a separate series from your pressure data. Choose the Connection Line option for the reference line series.

Jerry

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Answer 2

Tom Roehl Author

Level 1

10 points

Mar 31, 2014 4:10 PM in response to Jerrold Green1

That's a good tip and it almost gets me what I want but not quite unless I'm missing some trick. I'm able to create a scatter chart and add my observations and that part is good, but I can't quite get the reference line the work unless I create a table coloumn that has the reference value for each observation. What I was really hoping to do is to just have one cell in a table somewhere that is my reference value. I tried doing something like X Value = Observations::A and Y Value is Thresholds::A1 where column A in the Observations table is the date and the cell Thresholds::A1 is the cell that contains the value I want for my refernce line. What ends up happening is that the reference line only shows up as a single point on the first observation date. Am I doing something wrong? Or can Numbers not do what I am trying to do?

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Answer 3

Mar 31, 2014 6:37 PM in response to Tom Roehl

Tom,

You've just repeated your first post, and I read that one earlier. I'll make an example for you...

In this example, the Plus marks are the pressure series and the Solid line is the limit series.

Jerry

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Answer 4

Barry

Level 9

59,861 points

Mar 31, 2014 6:43 PM in response to Tom Roehl

Hi Tom,

A scatter chart will plot only the tata points that it has, and will connect only consecutive data points in a series, If there are gaps in the column containing the 'straight line' values, then points on either side of that gap will not be connected.

If the reason you want to enter only one value is that you what to be able to shift the reference value, that can be done. Select a cell to contain that value (eg. C1), then in all cells inthe column to contain the value to be charted as the reference line place the formula =$C$1

(BP values generated randomly within a range).

Regards,

Barry

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Answer 5

Tom Roehl Author

Level 1

10 points

Mar 31, 2014 6:52 PM in response to Barry

Barry, your example is basically what I am trying to achieve. The only thing I was trying to avoid was having to repeat the threshold values for each observation. I.e. the 80 and 120 values in your example.

The solution Jerry gave gets closer but I would have to update the ending date for the second row of the Limit Series table each time I add a new observation. I was kind of hoping that I could create a data series where the X value is the date and the Y value was a fixed number but I can't get Numbers to accept it. One possible solution is to see if there is a formula that I can use for the second date in the Limit Series table which returns the latest date in the observation table. Is there such a function?

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Answer 6

Mar 31, 2014 7:01 PM in response to Tom Roehl

In my example, the start date is: =MIN(PRESSURE DATA::A) and the ending date is: =MAX(PRESSURE DATA::A)

Neither has to be manually updated.

Jerry

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Answer 7

Tom Roehl Author

Level 1

10 points

Mar 31, 2014 7:12 PM in response to Jerrold Green1

Thanks Jerry! I think that's the solution... I appreciate the help!

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Answer 8

Apr 9, 2014 7:12 PM in response to Tom Roehl

This is a very interesting topic to me, I can't help to read the good solution for twice and found it really valuable to learn its techniques. Very insightful question on the line chart creation. Since I am also new to a UI chart control, this topic really helps.

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Answer 9

Jun 14, 2014 8:36 AM in response to Tom Roehl

I am trying to do something similar with a slight variation.

I'm putting together a case report for a mdeical study and I want to show a plot of a patient's labaratory values with the normal range of lab values in the background. See below TSH (thyroid stimulating hormone) example. Ignore Free T4.

	3/11/13, 13:10	4/2/13, 11:05:00	3/13/14, 15:31:00			Reference Range
TSH	0.90	0.99	1.94			(0.3 to 3.0)

User uploaded file

Is this possible in numbers? or do i need to use different software?

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Answer 10

SGIII

Level 8

35,264 points

Jun 14, 2014 4:30 PM in response to mdiloreto

Hi mdiloreto,

Suggest you start a new thread and give details about you want to do, and how you want the result to look.

SG

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