Class Trendlines (PowerPoint VBA)
The class Trendlines represents a collection of all the Trendline objects for the specified series. To use a Trendlines class variable it first needs to be instantiated, for example
Dim trns as Trendlines
Set trns = ActiveWindow.RangeFromPoint.Chart.FullSeriesCollection(1).Trendlines()
Add
Creates a new trendline.
Add (Type, Order, Period, Forward, Backward, Intercept, DisplayEquation, DisplayRSquared, Name)
Dim trnln As Trendline
Set trnln = ActivePresentation.Slides(1).Shapes(1).Chart.FullSeriesCollection(1).Trendlines.Add()
Arguments
Optional arguments
The following arguments are optional
Type (XlTrendlineType) - One of the enumeration values that specifies the trendline type. The default is xlLinear.
Possible values are
| xlExponential | Uses an equation to calculate the least squares fit through points (for example, y=ab^x) . |
| xlLinear | Uses the linear equation y = mx + b to calculate the least squares fit through points. |
| xlLogarithmic | Uses the equation y = c ln x + b to calculate the least squares fit through points. |
| xlMovingAvg | Uses a sequence of averages computed from parts of the data series. The number of points equals the total number of points in the series minus the number specified for the period. |
| xlPolynomial | Uses an equation to calculate the least squares fit through points (for example, y = ax^6 + bx^5 + cx^4 + dx^3 + ex^2 + fx + g). |
| xlPower | Uses an equation to calculate the least squares fit through points (for example, y = ax^b). |
Order (XlTrendlineType) - The trendline order. Required ifType is set to xlPolynomial. If specified, the value must be an integer from 2 through 6.
Possible values are
| xlExponential | Uses an equation to calculate the least squares fit through points (for example, y=ab^x) . |
| xlLinear | Uses the linear equation y = mx + b to calculate the least squares fit through points. |
| xlLogarithmic | Uses the equation y = c ln x + b to calculate the least squares fit through points. |
| xlMovingAvg | Uses a sequence of averages computed from parts of the data series. The number of points equals the total number of points in the series minus the number specified for the period. |
| xlPolynomial | Uses an equation to calculate the least squares fit through points (for example, y = ax^6 + bx^5 + cx^4 + dx^3 + ex^2 + fx + g). |
| xlPower | Uses an equation to calculate the least squares fit through points (for example, y = ax^b). |
Period (XlTrendlineType) - The trendline period. Required ifType is set to xlMovingAvg. If specified, the value must be an integer greater than 1 and less than the number of data points in the series to which you are adding a trendline.
Possible values are
| xlExponential | Uses an equation to calculate the least squares fit through points (for example, y=ab^x) . |
| xlLinear | Uses the linear equation y = mx + b to calculate the least squares fit through points. |
| xlLogarithmic | Uses the equation y = c ln x + b to calculate the least squares fit through points. |
| xlMovingAvg | Uses a sequence of averages computed from parts of the data series. The number of points equals the total number of points in the series minus the number specified for the period. |
| xlPolynomial | Uses an equation to calculate the least squares fit through points (for example, y = ax^6 + bx^5 + cx^4 + dx^3 + ex^2 + fx + g). |
| xlPower | Uses an equation to calculate the least squares fit through points (for example, y = ax^b). |
Forward (Long) - The number of periods (or units on a scatter chart) that the trendline extends forward.
Backward (Long) - The number of periods (or units on a scatter chart) that the trendline extends backward.
Intercept (Trendline) - The trendline intercept. If specified, the value must be a double-precision floating-point number. If omitted, the intercept is automatically set by the regression, and the InterceptIsAuto property of the resulting Trendline object is set to True.
DisplayEquation (Boolean) - True to display the equation of the trendline on the chart (in the same data label as the R-squared value).
DisplayRSquared (Boolean) - True to display the R-squared value of the trendline on the chart (in the same data label as the equation).
Name - String
Count
Returns the number of objects in the collection.
Dim lngCount As Long
lngCount = ActiveWindow.RangeFromPoint.Chart.FullSeriesCollection(1).Trendlines.Count
Item
Returns a single Trendline object from the collection.
Item (Index)
Index: The index number for the object.
Dim trnln As Trendline
Set trnln = ActivePresentation.Slides(1).Shapes(1).Chart.FullSeriesCollection(1).Trendlines(Index:=1)