DEFDBL A-Z
SCREEN 12
WINDOW (0, -1)-(3, 2)
startomega = 0
endomega = 3
omegasteps = 2 ^ 10
deltaomega = (endomega - startomega) / omegasteps
twopi = 8 * ATN(1)
DEF fnf (t) = 3 * SIN(5 * t)
a = 0
b = 10
numberofsteps = 2 ^ 7
deltat = (b - a) / numberofsteps
omega = startomega
oldomega = omega
oldaccum = 0
FOR j = 1 TO omegasteps
        t = a + deltat / 2
        accum = 0
        FOR k = 1 TO numberofsteps
                deltaS = (fnf(t) * SIN(twopi * omega * t) * deltat) / (b - a)
                accum = accum + deltaS
                t = t + deltat
        NEXT k
        omega = omega + deltaomega
        LINE (oldomega, oldaccum)-(omega, accum)
        oldomega = omega
        oldaccum = accum
NEXT j