clear
defaults
generate x 0,,180 100
y=sind(x)
generate x1 0,,180 50
y1=exp(-x1/90)*sind(x1)
X[101:150] = X1[50:1:-1]
Y[101:150] = Y1[50:1:-1]
SET AREAFILLCOLOR red
scales\-messages -10 200 -.2 1.2 
GRAPH X Y
