Here's the docs copied from Blitz3D:
Floor# ( y# ) Parameters y = any number Description Rounds downward, i.e. in the direction of -Infinity. It is a common mistake to think this simply sets everything after the decimal point to zero. But this is true only for positive numbers: Floor( 1.75 ) ....... 1.0 Floor( -1.75 ) .... -2.0 See also Ceil and Int for other types of rounding. Example ; Ceil / Floor / Int example, three kinds of rounding. ; Move mouse. Escape quits. Graphics 640, 480 Const KEY_ESC = 1 SetBuffer BackBuffer() Origin 320, 240 MoveMouse 320, 240 : HidePointer While Not KeyDown( KEY_ESC ) Cls my = MouseY() - 240 Color 100, 100, 0 Line -320, my, 319, my DrawNumberLine y# = Float( -my ) / 32 Text 100, 50, " y = " + y Text 100, 70, " Ceil( y ) = " + Ceil( y ) Text 100, 90, " Floor( y ) = " + Floor( y ) Text 100, 110, " Int( y ) = " + Int( y ) Flip Wend End Function DrawNumberLine( ) ; vertical line with numeric labels Color 255, 255, 255 Line 0, -240, 0, 239 For n = -7 To 7 yn = -32 * n Line -2, yn, 2, yn Text -30, yn - 6, RSet( n, 2 ) Next End Function