Selecting every nth (e.g. 10th) row for a graph

**Mel_P** · 07-20-2009, 02:31 PM

Hello,

I have too many data points (time, value) for a graph.

I want to select every 10th or 20th point to plot. Any ideas how I can achieve this please.

I have tried selection
row 1
row 10
row 20

and extending it but this then selects 2, 11, 21 !!

Help please !!

Thanks, Mel

**zero760** · 07-20-2009, 02:38 PM

Press the CTRL key and then highlight the data points. Excel should
pick up the fields you want.

**Mel_P** · 07-20-2009, 05:01 PM

But I have 33,000 rows! So manual selection is out.

I am trying to do this:

row1>>>>>>>>link>>>>>>>>>row 1 (time, value)
row2>>>>>>>>>>>>>>>>>>>row10(time, value)
..>>>>>>>>>>>>>>>>>>>>>row20 (time, value)
row10
..
..
row20

so that I can easily graph the row1, row10, row20 pairs as they form a contiguous dataset I can lasoo.

**Mel_P** · 07-20-2009, 05:15 PM

I have 33,000 pairs of values from a logger.

-Time, concentration

How do I plot (or extract) every 20th pair of value (or some other defined interval)?

Any ideas please (macro, VBA NOT manual selection)

Thanks. Mel

**shg** · 07-20-2009, 06:35 PM

Threads merged -- there's no need to start a new one. Carry on.

**Mel_P** · 07-20-2009, 06:56 PM

Thanks mod - apols.

**shg** · 07-20-2009, 07:15 PM

Any reason not to do this with a simple formula?

If you really want code, post a workbook that shows input (not all 30000 rows) and desired output (like, where it goes).

**Mel_P** · 07-21-2009, 04:45 PM

Posted it on microsoft excel forum and a response telling me to use the INDIRECT function worked.

So solved!

**shg** · 07-21-2009, 05:08 PM

Well done.

Be aware that INDIRECT is a volatile function, so it recalculates every time anything changes. So is OFFSET, which is another alternative.

A better choice would be a solution that used INDEX.