Trendline Alert on Indicator

[Stephen]

Would it be possible to add the Alert function to Trendlines drawn on indicators?  It may be a lot of coding, so for an initial code release, the alert would sound if any unhidden indicator line crossed above or below the trendline.  Follow up code release would include a setting to allow the user to configure the specific indicator line (eg, on a MACD indicator, the MACD line versus the signal line; on ADX, +DMI versus -DMI versus ADX lines).

[Jerry Medved]

trendline alerts need to be able to fire without the chart being open. on the main time based chart, we can do that. on indicators, we can't. Not without computing the indicators.  You would have to use a Paintbar or scan for that.

[Mike Medved]

You can (kinda) do this yourself. All you have to do is do a paintbar or scan that would look at the indicator and compare it to the trendline formula.

 

The trendline formula is Y=X*A+B where

 

Y = Y value of the trendline

X = X value - basically the timestamp

A = slope

B = offset

if X1, Y1 and X2, Y2 are the anchor points of the trendline then you precalculate the slope and offset thus:

A = (Y2-Y1)/(X2-X1)

B = Y1-X1*A

 

Of course, X1 and X2 are also timestamps of the anchor points.