EXST7015 : Statistical Techniques II Geaghan Analysis of Covariance SAS example Page 1 14d-AnCova-maunaloa.doca 1 /* 2 *---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8; 3 DATA SET TITLE: ATMOSPHERIC CO2 CONC - MAUNA LOA OBSERVATORY, HAWAII, 1958-2001. 4 CONTRIBUTORS: C. D. KEELING, T. P. WHORF (AND THE CARBON DIOXIDE RESEARCH 5 GROUP), SCRIPPS INSTITUTION OF OCEANOGRAPHY, UNIVERSITY OF CALIFORNIA, 6 LA JOLLA, CALIFORNIA 92093-0444 7 SCOPE OF THE DATA: THE DATA FILE CONTAINS MONTHLY AND ANNUAL ATMOSPHERIC 8 CO2 CONCENTRATIONS DERIVED FROM THE SCRIPPS INSTITUTION OF 9 OCEANOGRAPHY'S (SIO's) CONTINUOUS MONITORING PROGRAM AT MAUNA LOA 10 OBSERVATORY, HAWAII. THIS RECORD CONSTITUTES THE LONGEST CONTINUOUS 11 RECORD OF ATMOSPHERIC CO2 CONCENTRATIONS AVAILABLE IN THE WORLD. 12 MONTHLY AND ANNUAL AVERAGE MOLE FRACTIONS OF CO2 IN WATER-VAPOR-FREE AIR 13 ARE GIVEN FROM MARCH 1958 THROUGH DECEMBER 2001, EXCEPT FOR A FEW INTERRUPTIONS. 14 DATA FORMAT: ALL CONC. ARE EXPRESSED IN PARTS PER MILLION BY VOLUME (PPMV) IN 15 THE SIO X99 MOLE FRACTION SCALE. MISSING VALUES ARE REPRESENTED BY -99.99. 16 *---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8; 17 */ 18 19 options nocenter nodate nonumber ls=80 ps=256; 20 data maunaloa; length month $ 9; 21 title1 'Trend analysis of carbon dioxide levels'; 22 infile 'C:\Geaghan\EXST\EXST7015New\Fall2002\SAS\maunaloa.co2.txt' firstobs=15 obs=58; 23 input @1 Year 4. @5 January 7. @12 February 7. @19 March 7. @26 April 7. @33 May 7. @40 24 June 7. @47 July 7. @54 August 7. @61 September 7. @68 October 7. @75 24 November 7. @82 December 7. @89 Annual 7.; 25 time = year - 1957; 26 CO2Level = January; mo = 1; month = 'January'; output; 27 CO2Level = February; mo = 2; month = 'February'; output; 28 CO2Level = March; mo = 3; month = 'March'; output; 29 CO2Level = April; mo = 4; month = 'April'; output; 30 CO2Level = May; mo = 5; month = 'May'; output; 31 CO2Level = June; mo = 6; month = 'June'; output; 32 CO2Level = July; mo = 7; month = 'July'; output; 33 CO2Level = August; mo = 8; month = 'August'; output; 34 CO2Level = September; mo = 9; month = 'September'; output; 35 CO2Level = October; mo = 10; month = 'October'; output; 36 CO2Level = November; mo = 11; month = 'November'; output; 37 CO2Level = December; mo = 12; month = 'December'; output; 38 drop January February March April May June July August September 39 October November December Annual; 40 run; NOTE: The infile 'C:\Geaghan\EXST\EXST7015New\Fall2002\SAS\maunaloa.co2.txt' is: File Name=C:\Geaghan\EXST\EXST7015New\Fall2002\SAS\maunaloa.co2.txt, RECFM=V,LRECL=256 NOTE: 44 records were read from the infile 'C:\Geaghan\EXST\EXST7015New\Fall2002\SAS\maunaloa.co2.txt'. The minimum record length was 102. The maximum record length was 102. NOTE: The data set WORK.MAUNALOA has 528 observations and 5 variables. NOTE: DATA statement used: real time 0.06 seconds cpu time 0.06 seconds 41 42 data maunaloa; set maunaloa; 43 if co2level lt 0 then co2level = .; 44 loglevel = log(co2level); 46 run; 48 *proc print noobs; run; 49 options ls=111 ps=56; 50 proc plot data=maunaloa; plot co2level*time; run; 51 options ls=80 ps=256; NOTE: There were 528 observations read from the data set WORK.MAUNALOA. NOTE: The PROCEDURE PLOT printed page 1. NOTE: PROCEDURE PLOT used: real time 0.05 seconds cpu time 0.03 secondsEXST7015 : Statistical Techniques II Geaghan Analysis of Covariance SAS example Page 2 14d-AnCova-maunaloa.doca Trend analysis of carbon dioxide levels Plot of CO2Level*time. Legend: A = 1 obs, B = 2 obs, etc. CO2Level | | 380 + | | | | C | B C D 370 + A C D C | C C C B | B C B B | C D D B | C C C A | C C C A 360 + A B C B D C B | B B B D B | C B C C C | A C D C B B | B E C B C B | C D B B B 350 + C B C B | C B E B | C C D B | C D D C | B D D C B | B B B C B 340 + B C D D B | C C D B B | C B D C B | C B D A |