/* star_harmonic.sas */ TITLE1 'Harmonic wave'; TITLE2 'Star Data'; /* Read in the data and compute harmonic waves to which data are to be fitted */ DATA data1; INFILE 'c:\data\star.txt'; INPUT lumen @@; t=_N_; pi=CONSTANT('PI'); sin24=SIN(2*pi*t/24); cos24=COS(2*pi*t/24); sin29=SIN(2*pi*t/29); cos29=COS(2*pi*t/29); /* Compute a regression */ PROC REG DATA=data1; MODEL lumen=sin24 cos24 sin29 cos29; OUTPUT OUT=regdat P=predi; /* Graphical options */ SYMBOL1 C=GREEN V=DOT I=NONE H=.4; SYMBOL2 C=RED V=NONE I=JOIN; AXIS1 LABEL=(ANGLE=90 'lumen'); AXIS2 LABEL=('t'); /* Plot data and fitted harmonic wave */ PROC GPLOT DATA=regdat(OBS=160); PLOT lumen*t=1 predi*t=2 / OVERLAY VAXIS=AXIS1 HAXIS=AXIS2; RUN; QUIT;