I’m trying to rework the volume profile script to an interactive one where I can select a custom bar range for volume profile calculation similar to the paid version on tradingview. I already made the script calculate correctly based on bar_index inputs, but the script plots the VP rows wrong. For some reason, it takes the pivot point high or low that is within [lastbar] index range from “bbars” which should be the beginning of volume calculation (attached screenshot). Instead, the script should fit all the VP rows to the high/low range between “bbars” and “lastbar” bar_index values, making the profile more detailed. The issue comes from this line: top = ta.highest(bbars)[lastbar] bot = ta.lowest(bbars)[lastbar] which I don’t know how to code in other way.

Also if you know how to convert the bar_index inputs (start bar/end bar) into interactive time.input it would be very helpful, thanks for your help and time!

Current script:

// This source code is subject to the terms of the Mozilla Public License 2.0 at https://mozilla.org/MPL/2.0/
// © LonesomeTheBlue

//@version=5
indicator('Volume Profile / Custom Range', overlay=true, max_boxes_count=200, max_bars_back=501)
bbars = input.int(title='Start Bar', defval=100, minval=1, maxval=500)+1
lastbar = input.int(title='End Bar', defval=40, minval=1, maxval=500)
cnum = input.int(title='Row Size', defval=100, minval=5, maxval=100)
percent = input.float(70., title='Value Area Volume %', minval=0, maxval=100)
poc_color = input.color(defval=#ff0000, title='POC Color', inline='poc')
poc_width = input.int(defval=2, title='Width', minval=1, maxval=5, inline='poc')
vup_color = input(defval=color.new(color.blue, 30), title='Value Area Up')
vdown_color = input(defval=color.new(color.orange, 30), title='Value Area Down')
up_color = input(defval=color.new(color.blue, 75), title='UP Volume')
down_color = input(defval=color.new(color.orange, 75), title='Down Volume')
show_poc = input.bool(defval = true, title = "Show POC Label")

top = ta.highest(bbars)[lastbar]
bot = ta.lowest(bbars)[lastbar]
dist = (top - bot) / 800
step = (top - bot) / cnum

// calculate/keep channel levels
levels = array.new_float(cnum + 1)
for x = 0 to cnum by 1
    array.set(levels, x, bot + step * x)

// get the volume if there is intersection
get_vol(y11, y12, y21, y22, height, vol) =>
    nz(math.max(math.min(math.max(y11, y12), math.max(y21, y22)) - math.max(math.min(y11, y12), math.min(y21, y22)), 0) * vol / height)

if barstate.islast
    // calculate/get volume for each channel and candle
    volumes = array.new_float(cnum * 2, 0.)
    for bars = lastbar to bbars - 1 by 1
        body_top = math.max(close[bars], open[bars])
        body_bot = math.min(close[bars], open[bars])
        itsgreen = close[bars] >= open[bars]

        topwick = high[bars] - body_top
        bottomwick = body_bot - low[bars]
        body = body_top - body_bot

        bodyvol = body * volume[bars] / (2 * topwick + 2 * bottomwick + body)
        topwickvol = 2 * topwick * volume[bars] / (2 * topwick + 2 * bottomwick + body)
        bottomwickvol = 2 * bottomwick * volume[bars] / (2 * topwick + 2 * bottomwick + body)
        for x = 0 to cnum - 1 by 1
            array.set(volumes, x, array.get(volumes, x) + (itsgreen ? get_vol(array.get(levels, x), array.get(levels, x + 1), body_bot, body_top, body, bodyvol) : 0) + get_vol(array.get(levels, x), array.get(levels, x + 1), body_top, high[bars], topwick, topwickvol) / 2 + get_vol(array.get(levels, x), array.get(levels, x + 1), body_bot, low[bars], bottomwick, bottomwickvol) / 2)
            array.set(volumes, x + cnum, array.get(volumes, x + cnum) + (itsgreen ? 0 : get_vol(array.get(levels, x), array.get(levels, x + 1), body_bot, body_top, body, bodyvol)) + get_vol(array.get(levels, x), array.get(levels, x + 1), body_top, high[bars], topwick, topwickvol) / 2 + get_vol(array.get(levels, x), array.get(levels, x + 1), body_bot, low[bars], bottomwick, bottomwickvol) / 2)

    totalvols = array.new_float(cnum, 0.)
    for x = 0 to cnum - 1 by 1
        array.set(totalvols, x, array.get(volumes, x) + array.get(volumes, x + cnum))

    int poc = array.indexof(totalvols, array.max(totalvols))

    // calculate value area
    totalmax = array.sum(totalvols) * percent / 100.
    va_total = array.get(totalvols, poc)
    int up = poc
    int down = poc
    for x = 0 to cnum - 1 by 1
        if va_total >= totalmax
            break
        uppervol = up < cnum - 1 ? array.get(totalvols, up + 1) : 0.
        lowervol = down > 0 ? array.get(totalvols, down - 1) : 0.
        if uppervol == 0 and lowervol == 0
            break
        if uppervol >= lowervol
            va_total += uppervol
            up += 1
            up
        else
            va_total += lowervol
            down -= 1
            down

    maxvol = array.max(totalvols)
    for x = 0 to cnum * 2 - 1 by 1
        array.set(volumes, x, array.get(volumes, x) * bbars / (3 * maxvol))


    // Draw VP rows
    var vol_bars = array.new_box(cnum * 2, na)
    for x = 0 to cnum - 1 by 1
        box.delete(array.get(vol_bars, x))
        box.delete(array.get(vol_bars, x + cnum))
        array.set(vol_bars, x, box.new(bar_index - bbars + 1, 
                                       array.get(levels, x + 1) - dist, 
                                       bar_index - bbars + 1 + math.round(array.get(volumes, x)), 
                                       array.get(levels, x) + dist, 
                                       border_width=0, 
                                       bgcolor=x >= down and x <= up ? vup_color : up_color))
        array.set(vol_bars, x + cnum, box.new(bar_index - bbars + 1 + math.round(array.get(volumes, x)), 
                                              array.get(levels, x + 1) - dist, 
                                              bar_index - bbars + 1 + math.round(array.get(volumes, x)) + math.round(array.get(volumes, x + cnum)), 
                                              array.get(levels, x) + dist, 
                                              border_width=0, 
                                              bgcolor=x >= down and x <= up ? vdown_color : down_color))

    // Draw POC line and label
    poc_level = (array.get(levels, poc) + array.get(levels, poc + 1)) / 2
    var line poc_line = na
    line.delete(poc_line)
    poc_line := line.new(bar_index - bbars + 1, poc_level, bar_index - bbars + 2, poc_level, extend=extend.right, color=poc_color, width=poc_width)
    
    if show_poc
        var label poc_label = na
        label.delete(poc_label)
        poc_label := label.new(bar_index + 15, poc_level, 
                               text = "POC: " + str.tostring(math.round_to_mintick(poc_level)),
                               style = close >= poc_level ? label.style_label_up : label.style_label_down)

I’m trying to rework the volume profile script to an interactive one where I can select a custom bar range for volume profile calculation similar to the paid version on tradingview. I already made the script calculate correctly based on bar_index inputs, but the script plots the VP rows wrong. For some reason, it takes the pivot point high or low that is within [lastbar] index range from “bbars” which should be the beginning of volume calculation (attached screenshot). Instead, the script should fit all the VP rows to the high/low range between “bbars” and “lastbar” bar_index values, making the profile more detailed. The issue comes from this line: top = ta.highest(bbars)[lastbar] bot = ta.lowest(bbars)[lastbar] which I don’t know how to code in other way.