Next Page Previous Page Home Tools & Aids Search Handbook
1. Exploratory Data Analysis
1.3. EDA Techniques
1.3.3. Graphical Techniques: Alphabetic Scatter Plot

Scatter Plot: Exponential Relationship

Scatter Plot Showing Exponential Relationship scatter plot showing exponential relationship
Discussion Note that a simple straight line is grossly inadequate in describing the relationship between X and Y in this plot of the CHWIRUT2.DAT data set. A quadratic model would prove lacking, especially for large values of X. In this example, the large values of X correspond to nearly constant values of Y, and so a non-linear function beyond the quadratic is needed. Among the many other non-linear functions available, one of the simpler ones is the exponential model
    \[ Y_{i} = A + B e^{CX_{i}} + E_{i} \]
for some A, B, and C. In this case, an exponential function would, in fact, fit well, and so one is led to the summary conclusion of an exponential relationship.
Home Tools & Aids Search Handbook Previous Page Next Page