# set terminal png transparent nocrop enhanced font arial 8 size 420,320 
# set output 'bivariat.7.png'
set samples 59, 59
set title "Greatest Common Divisor (for integers only)" 0.000000,0.000000  font ""
set xrange [ * : * ] noreverse nowriteback  # (currently [1.00000:59.0000] )
f(x)=sin(x-1)-.75*sin(2*x-1)+(x**2)/8-5
integral_f(x) = (x>0)?integral1a(x):-integral1b(x)
integral1a(x) = (x<=0)?0:(integral1a(x-delta)+delta*f(x))
integral1b(x) = (x>=0)?0:(integral1b(x+delta)+delta*f(x))
integral2_f(x,y) = (x<y)?integral2(x,y):-integral2(y,x)
integral2(x,y) = (x>y)?0:(integral2(x+delta,y)+delta*f(x))
ack(m,n) = (m == 0) ? n + 1 : (n == 0) ? ack(m-1,1) : ack(m-1,ack(m,n-1))
min(x,y) = (x < y) ? x : y
max(x,y) = (x > y) ? x : y
gcd(x,y) = gcd1(rnd(max(x,y)),rnd(min(x,y)))
rnd(x) = int(x+0.5)
gcd1(x,y) = (y == 0) ? x : gcd1(y, x - x/y * y)
delta = 0.2
plot gcd(x, 60)