rich,
I see that TREND1 hasn't answered your question yet. It is quite possible he didn't understand your question. It is more likely he does not understand how his data is quantized prior to calculating brick boundaries, so he doesn't know how to answer the question. Maybe the 1 in the header means one minute, or maybe it means one tick, or maybe it's just a placeholder and means nothing on an intraday chart. My own opinion is that seconds versus a minute is hair not worth splitting.
My software gives me no means of selecting time interval for intraday P&F charts or Renko charts. I hope you know that a Renko chart is the same as a P&F chart with a retrace value of one brick, and each brick, whether it goes up or down, is placed in the next horizontal slot instead of in columns. My software also does not allow the use of closing data since it does only H/L intraday charts. For daily charts that do Renko and P&F, the bricks come and go (drawn, erased, and redrawn, and re-erased, etc.) during the day and do not stick till the end of day. That would be a real bummer if you tried to trade disappearing bricks. Same for a weekly. The same should be true for an intraday H/L P&F chart if it used minute data because there could be many ticks within a minute. I think reputable software does this because they want the user to see what the chart would look like if trading was stopped at any time during the day.
