Then, anytime TLEq is empty, line 4 errors because it cannot carry out the CDbl(Mid()) an empty TLEq.

The issue begins in line 2 where TLEq is inconsistently left blank during the loop some iterations all the trendline equation are extracted, sometimes only some are, and other times no equations are extracted. To get the equation - slope and offset - of the original trend line, select the trend line on the chart, right-click and choose Format Trendline. There has been no issues with graphing, trendlines showing up, or trendline equations displaying. However, you can take the equation for the trend line and calculate the data that comprise it, then create a new data set that adjusts for the slope of the trend line that you want to use. If you change the values in E3:E22, the trend () function will update Cell E24 for your new input at Cell A24. Cell C24 contains the X3 formula (A24A24A24) for the new X. Cell B24 contains the X2 formula (A24A24) for the new X. In lines above these (not included), the series are added, trendlines inserted, and DisplayEquation is called for each trendline. Cell A24 contains the new X, and is the cell to change to update the formula in E24. However, when I tried to use the original x data to calculate y using the trendline equation, it doesn't appear right. The CDbl(Mid()) is used to trim TLEq to just the slope and convert to a Double. Excel trendline looks fine but the equation is completely wrong I used excel to fit a curve to some data points (x,y). TLEq is a string to temporarily hold the full text of the trendline equation (intercept set to 0 so simple y = mx equation). SelectedSheets is an array filled with the sheets the user selects to be analyzed from a multi-select userform listbox. ModulusArr(j) = CDbl(Mid(TLEq, 4, Len(TLEq) - 4)) I want to report the slope average of all the trendlines and I've written the code below to do this action: For j = 1 To UBound(SelectedSheets) I've had success with everything except extracting the trendline slopes. I'm currently making a macro to extract raw data from multiple csvs, print it in different sheets, trim extraneous data, plot data from each sheet on a single graph with individual trendlines, and report some information for said trendlines and data.

Excel trendline custom equation