Scatter graph with step wise data

[KateB]

Just a quick question, i'm trying to graph some data, for which I've
used a x-y scatter chart. So far, so good, the data represents an
average value for a a 1/2 day period.

The chart interpolates between my points, instead of displaying
stepwise data, with the value displayed being the average for the next
period (until the new point).

I can't for love nor money find an option in the charts to do this -
am I missing something??

Hope this makes sense, let me know if I can post a picture somwhere!

Thanks!
Kate

 

[Dougaj4]

Just a quick question, i'm trying to graph some data, for which I've
used a x-y scatter chart.  So far, so good, the data represents an
average value for a a 1/2 day period.

The chart interpolates between my points, instead of displaying
stepwise data, with the value displayed being the average for the next
period (until the new point).

I can't for love nor money find an option in the charts to do this -
am I missing something??

Hope this makes sense, let me know if I can post a picture somwhere!

Thanks!
Kate

Right click on the graph, select "Chart Type", then select an option
with straight lines between the points, rather than curved lines.

 

[KateB]

I'm not sure that we're on the same page - it's not a straight line /
curved line problem, it's a "style" of interpolation.

For example, if I had the following data:-

x y
0 5
1 6
3 7

If I wanted the x value for x=0.5, y should be 5 (i.e. y = 5 for x = 0
to 1), not 5.5 (if it was interpolated)

I know I can do this, if I fiddled with the data and made a series
like so:-
x y
0 5
0.99 5
1 6
2.99 6
3 7

But that seems a lot of work for something that I want to do
repeatedly.... I would have thought that Excel might have another
option for drawing lines between the points. The chart type is closer
to a column chart, but the x values are not evenly spaced, so I can't
use that.

Thanks,
Kate

 

[Dougaj4]

I'm not sure that we're on the same page - it's not a straight line /
curved line problem, it's a "style" of interpolation.

Kate, you're right, I didn't understand what you wanted to do.

As far as I know there is no way to do what you want automatically,
other than writing a macro to generate the additional data points for
the steps.

 

[Lori]

Try one of the methods from this thread:
http://groups.google.com.au/group/microsoft.public.excel/browse_thread/thread/f90d906f1d1bf80f
HTH.

 

[Dougaj4]

Based on the link from Lori, but to my mind a bit simpler:

You can generate a new set of data to plot a stepped line with a
simple set of =INDEX() functions.
If your original data is in Datarange, and you want to generate the
modified data starting on Row 1, in three adjacent colums (say D, E,
F) put:

Row 1: 1, =INDEX(Datarange,$D1,1), =INDEX(Datarange,$D1,2)
Row 2: +D1+1, =INDEX(Datarange,$D2,1), +F1
Row 3: +D2, +E2, =INDEX(Datarange,$D3,2)

Then copy Rows 2 and 3 down as far as necessary and plot your graph
using Colums E and F as your XY data.

 

[KateB]

Cheering! That's great, thanks so much!

Kate