ExcelBanter - Need to get slope of peaks on excel graph

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Need to get slope of peaks on excel graph

I have a graph with many peaks which are decreasing logarithmically and i
need to get the slope of these peaks ignoring the "Noise" which is below
these peaks.

Any suggestions ???

Sorry I probaly didnt word the question well. My graph has many peaks e.g.
20 peaks, each one smaller than the previous one. What i am trying to do is
draw a lins through the top of these peaks and then get the slope of this
line.

I have tried using the trendling but with no success. It does give me ths
slope of the whole graph which is useful but not what i am looking for.
Regards

Capillod

"Capillod" wrote:

I have a graph with many peaks which are decreasing logarithmically and i
need to get the slope of these peaks ignoring the "Noise" which is below
these peaks.

Any suggestions ???

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capillod wrote:
<blockquote "
type="cite"
<pre wrap=""Sorry I probaly didnt word the question well. My graph has many peaks e.g.
20 peaks, each one smaller than the previous one. What i am trying to do is
draw a lins through the top of these peaks and then get the slope of this
line.

I have tried using the trendling but with no success. It does give me ths
slope of the whole graph which is useful but not what i am looking for.
Regards

Capillod

"Capillod" wrote:

</pre
<blockquote type="cite"
<pre wrap=""I have a graph with many peaks which are decreasing logarithmically and i
need to get the slope of these peaks ignoring the "Noise" which is below
these peaks.

Any suggestions ???
</pre
</blockquote
</blockquote
<font face="Arial"<br
<br
Can you create a helper column which contains only the data points for
the peaks.Â* Then plot that on your chart also (in some invisible color
if you wish) and put a trend line through them, rather than through all
your data points.<br
<br
For a one time use you can probably manually copy over a few relevant
peak data points easiest.Â* If this is some repeated process you want to
automate then you should be able to automatically copy over only the
points immediately following a change in sign of the slope or some such.<br
<br
Good luck....<br
<br
Bill<br
</font
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</html

You have what looks like a decaying harmonic process. Something like
amplitude versus time.. Assume that times are in A1 through A1000. Assume
that amplitudes are in B1 through B1000. In column C2 enter =B2-B1 and copy
the formula down. Column C will show if you are ascending or descending.

In Column D3 enter =IF(AND(C3<0,C20),1,0)
Column D will have zeros everywhere except just after the peaks it will have
ones.

Use Tools - Filter to see only the peaks. Plot this and measure the slope.

--
Gary's Student

"Bill Martin -- (Remove NOSPAM from addre" wrote:

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
<html
<head
<meta content="text/html;charset=UTF-8" http-equiv="Content-Type"
</head
<body bgcolor="#ffffff" text="#000000"
capillod wrote:
<blockquote "
type="cite"
<pre wrap=""Sorry I probaly didnt word the question well. My graph has many peaks e.g.
20 peaks, each one smaller than the previous one. What i am trying to do is
draw a lins through the top of these peaks and then get the slope of this
line.

I have tried using the trendling but with no success. It does give me ths
slope of the whole graph which is useful but not what i am looking for.
Regards

Capillod

"Capillod" wrote:

</pre
<blockquote type="cite"
<pre wrap=""I have a graph with many peaks which are decreasing logarithmically and i
need to get the slope of these peaks ignoring the "Noise" which is below
these peaks.

Any suggestions ???
</pre
</blockquote
</blockquote
<font face="Arial"<br
<br
Can you create a helper column which contains only the data points for
the peaks. Then plot that on your chart also (in some invisible color
if you wish) and put a trend line through them, rather than through all
your data points.<br
<br
For a one time use you can probably manually copy over a few relevant
peak data points easiest. If this is some repeated process you want to
automate then you should be able to automatically copy over only the
points immediately following a change in sign of the slope or some such.<br
<br
Good luck....<br
<br
Bill<br
</font
</body
</html