Programming Assignment 2

CSC 323 Data Analysis and Statistical Software

Due: 5/14/98

A colleague is interested in predicting Processing Time from Image Complexity. Use simple linear regression methods to analyze her dataset.

Assume that your colleague is a computer graphics student and that she has developed a new algorithm to process images. She has tested the algorithm on several images of the same size and collected the following measurements for each image:

• Processing Time (ms)
• Image Complexity

The image link contains data for this experiment.

1. Write a SAS program to analyze this data. Your program should do the following:
   • Execute the PRINT procedure.
   • Generate estimates of the slope and intercept using the REG procedure.
   • Generate residuals using the REG procedure.
   • Produce a scatterplot of the dependent variable vs. the independent variable.
   • Produce a residual plot.
   • Execute PROC UNIVARIATE with the NORMAL and PLOT options for the residuals.

   Note:For PROC PRINT, be sure to use labels for column headings rather than variable names. Use names for data sets and variables that are meaningful. You should generate an appropriate title for the output of these procedures.

2. Write a short analysis (no more than two pages) of the output of your SAS program. Your analysis should (at least) address the following:
   • State the regression model including symbols for all of its parameters.
   • Give the estimates of the model parameters.
   • State the regression equation.
   • Interpret the coefficients of the regression equation.
   • Interpret the r-square value from the Analysis of Variance section of your output.
   • Determine the correlation between your dependent and independent variables.
   • Comment on the model assumptions.