* PS5.2, using DATA3-7, SHAZAM command file for Example 5.2
SAMPLE 1 57
READ(data3-7) COST AGE MILES
*
* The variable E is defined as the cumulative expenditure at time t 
* on the maintenance (excluding gasoline) for a given automobile.  In
* this case, E is equal to the variable COST.
*
GENR E=COST
*
* Model A
*
OLS E AGE / RESID=U1
GENR APE1=100*ABS(U1)/COST
GENR MAPE1=SUM(APE1)/57
*
* Model B
*
OLS E MILES / RESID=U2
GENR APE2=100*ABS(U2)/COST
GENR MAPE2=SUM(APE2)/57
*
* Model C        
*
OLS E AGE MILES / RESID=U3
GENR APE3=100*ABS(U3)/COST
GENR MAPE3=SUM(APE3)/57
*
* The pairwise correlation coefficients for AGE and MILES are calculated
* using the PCOR option on the STAT command. Note, these correlations are
* based on the coefficients.  If the PCOR option is specified on an OLS
* regression then SHAZAM will print the correlation matrix of the 
* estimated coefficients.
*
STAT AGE MILES / PCOR
SMPL 57 57
PRINT MAPE1 MAPE2 MAPE3
*
DELETE / ALL
STOP