Trend lines on line graphs

[dshearer]

I am trying to add two different trend lines to the same set of data on a
line graph but cannot do it!

To give you more of an idea:

I have been running a psychological experiment where i have been observing
the occurence of a specific behaviour each week for 20 weeks. However, at
week 5 i introduced an intervention which should change the measured
behaviour. To demonstrate this, i need to display a trendline for weeks 1 -
5 and a second trendline for weeks 5-20.

Does anyone have any ideas how to do this?

 

[Bernard Liengme]

Make the chart (I assume it is XY) from two separate ranges.
Start with a chart made from weeks 1 thru 5 data.
Now select data (both the x and y columns) for the weeks 5-20; copy; click
chart; use menu item Edit | Paste Special and specify New Series with
x-values ion first column
Now you can add trendlines for the separate series
You can format the series to look identical if that is your need.
best wishes

 

[dshearer]

Thanks for getting back so quick Bernard. I have had a go at your procedure
and it nearly works. However, when i add the weeks 5-20 one of two things
happens. If I select "add cells as new series" it overlays the data points,
such that week 5 is on top of week one. If I select "add cells as new
points" it pastes the values in but it links the two data set together, such
that when i add a trendline it does it across all the data point again!

Any ideas?

 

[Bernard Liengme]

I should have said Range A is week 1 to 5
and Range B is week 6 to 20
Send me (my private email) your file and I will show you the result

 

[Bernard Liengme]

remove TRUENORTH

 

[integreat]

sounds like your data is from experimental test.

Any test like the one you are using should have the same time duration
for both tests.

If your data is in columns, then the first test data (y values ) goes
into, say, column A and the data from your second test (y values) goes
into, say, column B. Then to display two trend lines on the same chart
just select columns A and B as far as your data is recorded. Then use
the chart wizard in the usual way. If one column has more data cells
than the other you can manually edit the ranges.