/* Logarithm Regression */

/*
   X = Wind Velocity
   Y = Soil Erosion
   Log_Y = Log(Y)

   There appears to be non-linear (curved) relation between X and Y.
   But there appears to be a linear relation between X and Log(Y).
*/

Data Erosion;
        input X  Y  Log_Y;
Cards;
        13.5    5       0.6990
        13.5    15      1.1761
        14      35      1.5441
        15      25      1.3979
        17.5    25      1.3979
        19      70      1.8451
        20      80      1.9031
        21      140     2.1461
        22      75      1.8751
        23      125     2.0969
        25      190     2.2788
        25      300     2.4771
        26      240     2.3802
        27      315     2.4983
Proc GLM;
        Model Log_Y = X / CLM;     /* replace Log_Y by y and run */
        Output out = New    P = Predict    R = Resid;
Proc Plot;
        Plot Log_Y * X;
        Plot Predict * X;
Run;