Chart showing 30% decline, over any 30 day period?

[iamamazing]

I'd like to see a chart of the S&P, that highlights any day, since it's inception, that closed 30% lower than the opening, 30 days prior. (FYI, I'd like to do the same for 25% and 20% declines as well). Can you help?

 

[Joshua]

def Drop = Open[30] - Close >= Open[30] * 0.3;
plot Arrow = Drop;
Arrow.setpaintingStrategy(paintingStrategy.BOOLEAN_ARROW_DOWN);

 

[iamamazing]

You're amazing. TY! I've attached a screenshot showing the study on the ES. Can you walk me through what this is saying? (FYI, I edited the script and made a version showing a 25% drop as well.) Would love to understand what this is communicating. TY.
Screenshot of 30% drop
Screenshot of 25% drop

Thank you so much. This is so amazing that we can customize charts like this.

 

[Joshua]

Its a rather simple expression, I guess I could over-explain it.

The first part is a boolean expression, or in other words a comparison.
X >= Y
Is X greater than or equal to Y?
The result is true or false, or in thinkscript, yes or no, both of which translate to 1 or 0.
This value is assigned to the variable Drop

Open[30] is the opening price 30 bars back.
Close is the current price.
Subtracting Close from Open[30] gives you the point drop.

Open[30] * 0.3 gives you %30 of Open[30] in points.

Is the point drop greater or equal to %30 of open[30]?

Plot just tells it to mark the screen in someway, it defaults to a line.
setpaintingStrategy(paintingStrategy.BOOLEAN_ARROW_DOWN) changes that line to a down arrow
if the condition is True/Yes/1 it paints an arrow, otherwise its blank.
this type arrow, being Boolean, pegs the arrow to the top of the bar.

paintingStrategy.ARROW_DOWN, on the other hand, would just create a decorative line out of arrows.

 

[iamamazing]

This is so great. Thank you for taking the time to break it down. If I wanted to adjust the 25% (or another version of the script), is there a way to change the color of the arrow? Or some other way to help differentiate if I have both "studies" visible on one chart?

Thank you again, really appreciate it.

Jon

 

[Joshua]

Input DaysAgo = 30;
Input PercDrop = 25;
Def Drop = Open[DaysAgo] - Close >= Open[DaysAgo] * (PercDrop * 0.01);
Plot Arrow = Drop;
Arrow.setpaintingStrategy(paintingStrategy.BOOLEAN_ARROW_DOWN);

This should allow you to adjust the drop since how ever many days ago in the settings panel rather than editing the code. You can also change the color right in the same panel.

 

[iamamazing]

How do I navigate to that options screen?

 

[MerryDay]

How do I navigate to that options screen?

Click on the gear icon to the right of the study name in your chart study tab

 

[iamamazing]

TY! I was able to make the arrow bigger and a different color on one so I can see where there is overlap too. Thanks so much!!