signum x    signum[x]

Where x (or its underlying value for temporals) is

• null or negative, returns -1i
• zero, returns 0i
• positive, returns 1i

q)signum -2 0 1 3
-1 0 1 1i

q)signum (0n;0N;0Nt;0Nd;0Nz;0Nu;0Nv;0Nm;0Nh;0Nj;0Ne)
-1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1i

q)signum 1999.12.31
-1i

Find counts of price movements by direction:

select count i by signum deltas price from trade