predictYfromLin: Predict a New Y Value from a Linear Regression

In ecology-rocks/MakeMyForests: SORTIE-ND Preparation From Forest Inventory Data

Description

This function takes a dataframe and formula, calculates a linear regression, then predicts new Y values from the linear regression. It returns those Y values as a vector. You can provide a "new x" value directly in "newX", or tell the function where a column is that contains your predictive value(s) in "newCol."

Usage

predictYfromLin(x, formula, newX = NULL, newCol = "minAge")

Arguments

x	The dataframe to use for prediction.
formula	The formula for the linear regression, in the format "y ~ x"
newX	Optional. The value you want to predict, given X. If left blank, it assumes that there is a column in the dataframe called "minAge" that is populated with the values you want to predict for. It takes the unique() of x$minAge and uses that as the newX. This ensures that if you're wrapping in doFxBySort, you can have values specific to a given subset just by having them in another column, and since repeats are ignored, you can have as many or as few up to the nrow() of your column.
newCol	What you want your new column to be named.

Note

This function does not police your use. If you predict from an X that is outside of your range of original x's, that is on you.

Examples

data <- data.frame(x=runif(30, min=0, max=25), y=runif(30, min=0, max=100), newVal=30)
 predictYfromLin(data, "y~x", newCol="newVal")

ecology-rocks/MakeMyForests documentation built on May 15, 2019, 7:57 p.m.