~~NOTOC~~
<=[[4rpl:start| Index]] \\
<= [[4rpl:start#Math]]  

====== sign0 ======
SIGN0(<-val)

===== Description =====
Returns the sign of the input value.
Return value is 1 when f is positive, -1 when f is negative, and 0 if the input value is 0.

===== Examples =====
<code 4rpl>
trace(sign(42)) #prints '1'
</code>
<=[[4rpl:start| Index]]