software

Is there a way to link to the coefficients of a trend line? I have some data
plotted with a exponential trend line fitted to it and the equation of the
trend line (y = cx^d) shown on the chart. Rather than manually copying c and
d to use them in another worksheet, I would like to link to them so that I
don't have to re-copy everytime my data changes. Can this be done?

Thanks.

If you really are using an exponential fit lt; y=Aexp(Bx) gt; see
www.stfx.ca/people/bliengme/E...amp; LOGEST.htm
If you are using a power fit lt; y = Ax^B gt; then see the lower half of
www.stfx.ca/people/bliengme/E...Polynomial.htm
best wishes
--
Bernard V Liengme
www.stfx.ca/people/bliengme
remove caps from email

quot;Jakequot; gt; wrote in message
...
gt; Is there a way to link to the coefficients of a trend line? I have some
gt; data
gt; plotted with a exponential trend line fitted to it and the equation of the
gt; trend line (y = cx^d) shown on the chart. Rather than manually copying c
gt; and
gt; d to use them in another worksheet, I would like to link to them so that I
gt; don't have to re-copy everytime my data changes. Can this be done?
gt;
gt; Thanks.
Cool, thanks. You're right - it's power fit, not exponential.

quot;Bernard Liengmequot; wrote:

gt; If you really are using an exponential fit lt; y=Aexp(Bx) gt; see
gt; www.stfx.ca/people/bliengme/E...amp; LOGEST.htm
gt; If you are using a power fit lt; y = Ax^B gt; then see the lower half of
gt; www.stfx.ca/people/bliengme/E...Polynomial.htm
gt; best wishes
gt; --
gt; Bernard V Liengme
gt; www.stfx.ca/people/bliengme
gt; remove caps from email
gt;
gt; quot;Jakequot; gt; wrote in message
gt; ...
gt; gt; Is there a way to link to the coefficients of a trend line? I have some
gt; gt; data
gt; gt; plotted with a exponential trend line fitted to it and the equation of the
gt; gt; trend line (y = cx^d) shown on the chart. Rather than manually copying c
gt; gt; and
gt; gt; d to use them in another worksheet, I would like to link to them so that I
gt; gt; don't have to re-copy everytime my data changes. Can this be done?
gt; gt;
gt; gt; Thanks.
gt;
gt;
gt;

Actually, using this method gives me slightly different coefficients than the
numbers I got from the excel trendline equation. Any idea why?

Trendline:
a = 0.011
b = -0.433

Linest Equation
a = 0.014
b = -0.453

I only have 5 data points so might as well share those too:
1, 1.0985%
2, 0.7889%
3, 0.6603%
4, 0.6036%
5, 0.5432%
quot;Jakequot; wrote:

gt; Is there a way to link to the coefficients of a trend line? I have some data
gt; plotted with a exponential trend line fitted to it and the equation of the
gt; trend line (y = cx^d) shown on the chart. Rather than manually copying c and
gt; d to use them in another worksheet, I would like to link to them so that I
gt; don't have to re-copy everytime my data changes. Can this be done?
gt;
gt; Thanks.

My LINEST values are -0.4334173337 -4.5248442752

So my coefficients are
-0.4334173337 0.010836402

which are identical to those in the trendline equation.
I am using Excel 2003, what version are you using?
--
Bernard V Liengme
www.stfx.ca/people/bliengme
remove caps from email

quot;Jakequot; gt; wrote in message
...
gt; Actually, using this method gives me slightly different coefficients than
gt; the
gt; numbers I got from the excel trendline equation. Any idea why?
gt;
gt; Trendline:
gt; a = 0.011
gt; b = -0.433
gt;
gt; Linest Equation
gt; a = 0.014
gt; b = -0.453
gt;
gt; I only have 5 data points so might as well share those too:
gt; 1, 1.0985%
gt; 2, 0.7889%
gt; 3, 0.6603%
gt; 4, 0.6036%
gt; 5, 0.5432%
gt;
gt;
gt;
gt; quot;Jakequot; wrote:
gt;
gt;gt; Is there a way to link to the coefficients of a trend line? I have some
gt;gt; data
gt;gt; plotted with a exponential trend line fitted to it and the equation of
gt;gt; the
gt;gt; trend line (y = cx^d) shown on the chart. Rather than manually copying c
gt;gt; and
gt;gt; d to use them in another worksheet, I would like to link to them so that
gt;gt; I
gt;gt; don't have to re-copy everytime my data changes. Can this be done?
gt;gt;
gt;gt; Thanks.