What is Regression

Regression is used to map a data item to a real-valued prediction variable. In actuality, regression involves the learning of the function that does this mapping. Regression assumes that the target data fir into some known type of function (e.g. linear, logistic, etc.) and then determine the best function of this type that models the given data. Some type of error analysis is used to determine which function is "bedt". Standard linear is a simple example of regression. For example, a college professor wishes to reach a certain level of saving before his retirement. Periodically, he predicts what his retirement savings will be based on its current value and several past values. He uses a simple linear regression formula to predict this value by fitting past behavior to a linear function and then using this function to predict the values at points in the future. Based on these values, he then alters his investment portfolio.