DetSlope function

Determine slope for the log(y) and x regression manually

You choose a slope for terminal half-life.

DetSlope(x, y, SubTitle="", sel.1=0, sel.2=0)

Arguments

• x: vector values of x-axis, usually time
• y: vector values of y-axis, usually concentration
• SubTitle: subtitle to be shown on the plot
• sel.1: default index of the first element to use
• sel.2: default index of the last element to use

Details

Sometimes BestSlope cannot find terminal slope satisfactorily. Then you can use this function to choose manually. It returns the same format result with BestSlope with an attribute indicating used points.

Returns

• R2: R-squared

• R2ADJ: adjusted R-squared

• LAMZNPT: number of points used for the slope

• LAMZ: negative of the slope, lambda_z

• b0: intercept of the regression line

• CORRXY: correlation of log(y) and x

• LAMZLL: earliest x for lambda_z

• LAMZUL: last x for lambda_z

• CLSTP: predicted y value at the last point, predicted concentration for the last time point

Author(s)

Kyun-Seop Bae k@acr.kr

See Also

Slope

Examples

DetSlope(Theoph[Theoph$Subject==1, "Time"], Theoph[Theoph$Subject==1, "conc"])
DetSlope(Indometh[Indometh$Subject==2, "time"], Indometh[Indometh$Subject==2, "conc"])