Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
Department of Civil and Environmental Engineering 1.017 Computing and Data Analysis for Environmental Applications Quiz 3 Thursday, December 4, 2003 Please answer all questions on a separate piece(s) of paper with your name clearly identified: Problem 1 ( 30 points) Consider the following model of temporal fluctuations in air temperature: y ( t ) = a 1 + a 2 cos[ π t /12]cos[ π t /4380] + e Where y ( t ) is temperature in degrees C, t is the number of hours from midnight Dec 31, a 1 and a 2 are unknown regression coefficients, and e is assumed to be a zero mean normally random residual error with an unknown standard deviation σ e . The first cosine function accounts for daily (diurnal) fluctuations while the second cosine function accounts for seasonal fluctuations. Suppose that you have a file called temp.txt that consists of a column of daily temperature measurements taken over a 2 year period. Write a MATLAB program, using the internal MATLAB regress function, to perform a regression analysis for this problem. Make sure that your program does the following: a) Computes least-squares estimates of a 1 and a 2 from the data in temp.txt . b) Plots a regression curve on the same axes as the temperature measurements. c) Plots on the same axes as the regression curve and temperature measurements a pair of 95% confidence interval curves for the predicted temperature, over the 2 year measurement period. The MATLAB documentation for the regress function is attached at the end of this exam. Problem 2 ( 10 points) Consider the regression ANOVA table presented below. Indicate whether the regression is significant at the 95% confidence level. Compute the R 2 value. Source
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 11/29/2011 for the course CIVIL 1.00 taught by Professor Georgekocur during the Spring '05 term at MIT.

Page1 / 5


This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online