Texas Instruments TI-84 Plus Manual Book page 199

specifies one of four shading patterns.
pattern
pattern=1
pattern=2
pattern=3
pattern=4
specifies one of eight shading resolutions.
patres
patres=1
patres=2
patres=3
patres=4
patres=5
patres=6
patres=7
patres=8
Shade(lowerfunc,upperfunc[,Xleft,Xright,pattern,patres])
Chapter 8: Draw Instructions
vertical (default)
horizontal
¡
negative—slope 45
¡
positive—slope 45
shades every pixel (default)
shades every second pixel
shades every third pixel
shades every fourth pixel
shades every fifth pixel
shades every sixth pixel
shades every seventh pixel
shades every eighth pixel
196