Extension line to the left

[JDS]

Hello, How can I get the line to extend left all the way back up to the end of the chart left on this code. I tried and keep getting a moving average type line going through the bars.

def na = Double.NaN;
def bn = BarNumber();

input bars_back = 0;
def x = (!IsNaN(close[-bars_back]) and IsNaN(close[-(1 + bars_back)]));
input price = open;

# --- Main line (dynamic) ---
def line =
if bn == 1 then na
else if x then price
else if IsNaN(close) then line[1]
else line[1];

plot z = line;
z.SetDefaultColor(Color.CYAN);
z.SetLineWeight(2);

# --- Capture the most recent valid line value ---
def activeLine = if !IsNaN(line) then line else activeLine[1];

# --- Horizontal extension (perfectly flat) ---
plot extendLeft = if bn >= 1 then activeLine else na;

extendLeft.SetDefaultColor(Color.LIGHT_GRAY);
extendLeft.SetPaintingStrategy(PaintingStrategy.HORIZONTAL);
extendLeft.SetStyle(Curve.SHORT_DASH);
extendLeft.SetLineWeight(1);
extendLeft.HideBubble();
extendLeft.HideTitle();

# --- Optional vertical trigger marker ---
input test_vert = no;
AddVerticalLine(test_vert and x, "-");

 

[antwerks]

Hello, How can I get the line to extend left all the way back up to the end of the chart left on this code. I tried and keep getting a moving average type line going through the bars.

def na = Double.NaN;
def bn = BarNumber();

input bars_back = 0;
def x = (!IsNaN(close[-bars_back]) and IsNaN(close[-(1 + bars_back)]));
input price = open;

# --- Main line (dynamic) ---
def line =
if bn == 1 then na
else if x then price
else if IsNaN(close) then line[1]
else line[1];

plot z = line;
z.SetDefaultColor(Color.CYAN);
z.SetLineWeight(2);

# --- Capture the most recent valid line value ---
def activeLine = if !IsNaN(line) then line else activeLine[1];

# --- Horizontal extension (perfectly flat) ---
plot extendLeft = if bn >= 1 then activeLine else na;

extendLeft.SetDefaultColor(Color.LIGHT_GRAY);
extendLeft.SetPaintingStrategy(PaintingStrategy.HORIZONTAL);
extendLeft.SetStyle(Curve.SHORT_DASH);
extendLeft.SetLineWeight(1);
extendLeft.HideBubble();
extendLeft.HideTitle();

# --- Optional vertical trigger marker ---
input test_vert = no;
AddVerticalLine(test_vert and x, "-");

Replace your extension section with this block:

# --- Capture the most recent valid line value ---
def activeLine = if !IsNaN(line) then line else activeLine[1];

# --- Full historical extension (flat across all bars) ---
def extendLeftAll = if !IsNaN(activeLine) then activeLine else extendLeftAll[1];

plot extendLeft = extendLeftAll;
extendLeft.SetDefaultColor(Color.LIGHT_GRAY);
extendLeft.SetPaintingStrategy(PaintingStrategy.HORIZONTAL);
extendLeft.SetStyle(Curve.SHORT_DASH);
extendLeft.SetLineWeight(1);
extendLeft.HideBubble();
extendLeft.HideTitle();

What this does

• activeLine remembers your most recent valid price level.
• extendLeftAll simply keeps repeating that same level for all earlier bars — no moving average smoothing, no interpolation.
• It creates a perfectly horizontal dashed line that spans the entire visible chart (and beyond, if you scroll).
  Optional — If you only want the extension once a condition is set

If you want the line to appear only after your trigger x occurs, and still extend both ways (left and right):

def triggerPrice = if x then price else triggerPrice[1];
plot fullExtend = if !IsNaN(triggerPrice) then triggerPrice else Double.NaN;

fullExtend.SetDefaultColor(Color.LIGHT_GRAY);
fullExtend.SetPaintingStrategy(PaintingStrategy.HORIZONTAL);
fullExtend.SetLineWeight(2);

That way, the line only appears after the condition happens but spans both directions flatly.