If you have a formula, you can roll your own trendline.

In a column enter a sequence of X values which you want the trendline to span. In the next column, enter the formula based on the cells in the first column. Copy these 2 columns of data, select the XY chart, and use paste special to add the data as a new series, categories in first column.

Great website here. So I am wondering why the “Inverse” and “S” trendline options are not available in Excel? It seems there is a limited number of trendline options.

I just fitted my data to a bunch of curves in SPSS and the two best fit (with the highest R2 values) were “Inverse” and “S”. But for the documents I make I need to have excel graphs so was hoping to use the trendlines in Excel. Is there a way to plot an “inverse or “S” trendline in excel? I now have the formulas (e.g. y = -6.831 + (0.762/x) is the “Inverse” curve equation for one of my data sets) for the trendlines if that is any help.

Thanks in advance!
Lenore

Does deleting then redisplaying the label with the formula show an updated formula? If not, you probably need to delete and recreate the trendline itself with formula.

You can calculate the t-statistics for LINEST coefficients from the LINEST output table, and you can get p-values from these.

I have 2 questions: I have a series of graphs of climate data and stats for a given site. Each time I import data from a new climate station, I run a macro to calculate some seasonal climate statistics and then update the underlying data/titles for the graphs. The graphs are updated automatically (with one exception). I notice that when I change the underlying data, the trendline on the graph updates but the trendline formula on the graph does not. Is there a way to get the formula on the graph to update as well (I am using Excel 2010). Second, is there a way to quickly produce a p-value related to the slope of a linear trend (something alluded to by the first post here). I would like this to be autocomputed and shown on the updated graph as well. I know I can get a t-stat from the TINV fxn – maybe I just say something about the significance based on this?