ndays= 120 ; 360L*4
sample_per_day= 48 ; 240      ; Number of data per day
n= ndays* sample_per_day

period= 1.     ; Day
x= FINDGEN(n)/sample_per_day
y= 2.*SIN(2.*!pi*x/(period/2.))+ 2.*SIN(2.*!pi*x/period)+ 5.1* SIN(2.*!pi*x/(period*10))+ 5.*SIN(2.*!pi*x/(period*36))

dat=FLTARR(2,n)
dat[0,*]=x & dat[1,*]= y
OPENW,1,'sample_sin.d'
PRINTF,1, dat
CLOSE,1

END