// This work is licensed under a Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0) https://creativecommons.org/licenses/by-nc-sa/4.0/
// © LuxAlgo
//@version=5
indicator("Nadaraya-Watson Smoothers [LuxAlgo]", "LuxAlgo - Nadaraya-Watson Smoothers", overlay = true, max_lines_count = 500, max_labels_count = 500, max_bars_back=500)
//------------------------------------------------------------------------------
//Settings
//-----------------------------------------------------------------------------{
h = input.float(8.,'Bandwidth', minval = 0)
src = input(close,'Source')
repaint = input(true, 'Repainting Smoothing', tooltip = 'Repainting is an effect where the indicators historical output is subject to change over time. Disabling repainting will cause the indicator to output the endpoint of the estimator')
//Style
upCss = input.color(color.teal, 'Colors', inline = 'inline1', group = 'Style')
dnCss = input.color(color.red, '', inline = 'inline1', group = 'Style')
//-----------------------------------------------------------------------------}
//Functions
//-----------------------------------------------------------------------------{
//Gaussian window
gauss(x, h) => math.exp(-(math.pow(x, 2)/(h * h * 2)))
//-----------------------------------------------------------------------------}
//Append lines
//-----------------------------------------------------------------------------{
n = bar_index
var ln = array.new_line(0)
if barstate.isfirst and repaint
for i = 0 to 499
array.push(ln,line.new(na,na,na,na))
//-----------------------------------------------------------------------------}
//End point method
//-----------------------------------------------------------------------------{
var coefs = array.new_float(0)
var den = 0.
if barstate.isfirst and not repaint
for i = 0 to 499
w = gauss(i, h)
coefs.push(w)
den := coefs.sum()
out = 0.
if not repaint
for i = 0 to 499
out += src[i] * coefs.get(i)
out /= den
//-----------------------------------------------------------------------------}
//Compute and display NWE
//-----------------------------------------------------------------------------{
float y2 = na
float y1 = na
float y1_d = na
line l = na
label lb = na
if barstate.islast and repaint
//Compute and set NWE point
for i = 0 to math.min(499,n - 1)
sum = 0.
sumw = 0.
//Compute weighted mean
for j = 0 to math.min(499,n - 1)
w = gauss(i - j, h)
sum += src[j] * w
sumw += w
y2 := sum / sumw
d = y2 - y1
//Set coordinate line
l := array.get(ln,i)
line.set_xy1(l,n-i+1,y1)
line.set_xy2(l,n-i,y2)
line.set_color(l,y2 > y1 ? dnCss : upCss)
line.set_width(l,2)
if d * y1_d < 0
label.new(n-i+1, src[i], y1_d < 0 ? '▲' : '▼'
, color = color(na)
, style = y1_d < 0 ? label.style_label_up : label.style_label_down
, textcolor = y1_d < 0 ? upCss : dnCss
, textalign = text.align_center)
y1 := y2
y1_d := d
//-----------------------------------------------------------------------------}
//Dashboard
//-----------------------------------------------------------------------------{
var tb = table.new(position.top_right, 1, 1
, bgcolor = #1e222d
, border_color = #373a46
, border_width = 1
, frame_color = #373a46
, frame_width = 1)
if repaint
tb.cell(0, 0, 'Repainting Mode Enabled', text_color = color.white, text_size = size.small)
//-----------------------------------------------------------------------------}
//Plot
//-----------------------------------------------------------------------------}
plot(repaint ? na : out, 'NWE Endpoint Estimator', out > out[1] ? upCss : dnCss)
//-----------------------------------------------------------------------------}
