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"Gary Fritz" <fritz@xxxxxxxx> notices:
>Often it seems that TS does not plot, or erases, parts of indicator
>lines as it updates a chart in realtime. I've often seen this
>manifest as missing or "broken/dotted" lines where I *know* a line
>should be. You can look in the Data Window to verify that the
>indicator has a value at that point, even though there is no line on
>the screen. You can also replot the chart (by iconizing & restoring
>TS, or by switching to another workstation and back) and then it
>looks like it should.
You're running into a shortcut commonly taken in graphics programming
to speed up drawing to the screen. Since the action normally takes
place on the far right edge of the chart, a cruel fact known all too
well by experienced traders, TS calls on the "system" (some combination
of Windows and its video driver/video card combo) to scroll the chart
left one bar's width, then draws the new stuff into the narrow band
comprising the rightmost two bars. The theory is that the system has
efficient methods to scroll all that area, and that updating those
two rightmost bars will draw the necessary new stuff, allowing you to
plot on the previous bar with "plot1[1](..." and so forth.
TS is clever enough to know that the entire chart area must be refreshed
when the scaling changes, as you can observe when your chart continually
flashes in an up or down trend. The flashing is a good demonstration
of how inefficient it is to redraw the whole chart every tick.
Unfortunately, TS isn't clever enough to know when it's supposed to plot
new information outside that two bar interval. Try using an indicator
that has a "plot1[X](...)" for X > 1. You won't see the plot until
something causes a full-chart refresh.
The obvious solution would be for TS to maintain a list of special areas
that need updating as plotting occurs, and refresh those areas along
with the righthand two-bar column. This fix would probably have been
incorporated long ago if someone in a position of influence were actually
using TS to trade. :)
Jim
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