yesterday bar

[Waddah]

haw I can use iopen and iclose  to determine yesterday bar is bullish or bearish ? 

[Keith Watford]

if the close of bar[1] is bigger than the open of bar[1], it was bullish

Vice versa 

[William Roeder]

No need for iOpen or iClose if you want the chart symbol/period just use Open[]/Close[]