/* transfer.sas */ TITLE1 'Transfer function'; TITLE2 'of least squares fitted low pass filter'; /* Compute transfer function */ DATA data1; DO lambda=0 TO .5 BY .001; f=2*1/10; DO u=1 TO 20; f=f+2*1/(CONSTANT('PI')*u)*SIN(2*CONSTANT('PI')*1/10*u)*COS(2*CONSTANT('PI')*lambda*u); END; OUTPUT; END; /* Graphical options */ AXIS1 LABEL=('f' H=1 'a' H=2 F=CGREEK '(l)'); AXIS2 LABEL=(F=CGREEK 'l'); SYMBOL1 V=NONE C=GREEN I=JOIN L=1; /* Plot transfer function */ PROC GPLOT DATA=data1; PLOT f*lambda / VAXIS=AXIS1 HAXIS=AXIS2 VREF=0; RUN; QUIT;