Pine 腳本中的變量賦值

Question

我正在嘗試閱讀一些 pine 腳本以了解它是如何工作的。

但是有一些奇怪的事情我無法解釋。

例如 pivot 松樹腳本：

pivotX_open = float(na)
pivotX_open := nz(pivotX_open[1], open)
pivotX_high = float(na)
pivotX_high := nz(pivotX_high[1], high)
pivotX_low = float(na)
pivotX_low := nz(pivotX_low[1], low)
pivotX_prev_open = float(na)
pivotX_prev_open := nz(pivotX_prev_open[1])
pivotX_prev_high = float(na)
pivotX_prev_high := nz(pivotX_prev_high[1])
pivotX_prev_low = float(na)
pivotX_prev_low := nz(pivotX_prev_low[1])
pivotX_prev_close = float(na)
pivotX_prev_close := nz(pivotX_prev_close[1])

我無法理解這些初始化。 這似乎是一種常見的方式，但很難理解如何用自身初始化變量。

謝謝你的幫助。

Tradingview的完整代碼

//@version=5
indicator("Pivot Points Standard", "Pivots", overlay=true, max_lines_count=500, max_labels_count=500)

AUTO = "Auto"
DAILY = "Daily"
WEEKLY = "Weekly"
MONTHLY = "Monthly"
QUARTERLY = "Quarterly"
YEARLY = "Yearly"
BIYEARLY = "Biyearly"
TRIYEARLY = "Triyearly"
QUINQUENNIALLY = "Quinquennially"
DECENNIALLY = "Decennially"

TRADITIONAL = "Traditional"
FIBONACCI = "Fibonacci"
WOODIE = "Woodie"
CLASSIC = "Classic"
DEMARK = "DM"
CAMARILLA = "Camarilla"

kind = input.string(title="Type", defval="Traditional", options=[TRADITIONAL, FIBONACCI, WOODIE, CLASSIC, DEMARK, CAMARILLA])
pivot_time_frame = input.string(title="Pivots Timeframe", defval=AUTO, options=[AUTO, DAILY, WEEKLY, MONTHLY, QUARTERLY, YEARLY, BIYEARLY, TRIYEARLY, QUINQUENNIALLY, DECENNIALLY])
look_back = input.int(title="Number of Pivots Back", defval=15, minval=1, maxval=5000)
is_daily_based = input.bool(title="Use Daily-based Values", defval=true, tooltip="When this option is unchecked, Pivot Points will use intraday data while calculating on intraday charts. If Extended Hours are displayed on the chart, they will be taken into account during the pivot level calculation. If intraday OHLC values are different from daily-based values (normal for stocks), the pivot levels will also differ.")
show_labels = input.bool(title="Show Labels", defval=true, inline="labels")
position_labels = input.string("Left", "", options=["Left", "Right"], inline="labels")

var DEF_COLOR = #FB8C00
var arr_time = array.new_int()
var p = array.new_float()
p_show = input.bool(true, "P‏  ‏  ‏  ‏  ‏  ‏  ‏  ‏", inline="P")
p_color = input.color(DEF_COLOR, "", inline="P")
var r1 = array.new_float()
var s1 = array.new_float()
s1r1_show = input.bool(true, "S1/R1", inline="S1/R1")
s1r1_color = input.color(DEF_COLOR, "", inline="S1/R1")
var r2 = array.new_float()
var s2 = array.new_float()
s2r2_show = input.bool(true, "S2/R2", inline="S2/R2")
s2r2_color = input.color(DEF_COLOR, "", inline="S2/R2")
var r3 = array.new_float()
var s3 = array.new_float()
s3r3_show = input.bool(true, "S3/R3", inline="S3/R3")
s3r3_color = input.color(DEF_COLOR, "", inline="S3/R3")
var r4 = array.new_float()
var s4 = array.new_float()
s4r4_show = input.bool(true, "S4/R4", inline="S4/R4")
s4r4_color = input.color(DEF_COLOR, "", inline="S4/R4")
var r5 = array.new_float()
var s5 = array.new_float()
s5r5_show = input.bool(true, "S5/R5", inline="S5/R5")
s5r5_color = input.color(DEF_COLOR, "", inline="S5/R5")
pivotX_open = float(na)
pivotX_open := nz(pivotX_open[1], open)
pivotX_high = float(na)
pivotX_high := nz(pivotX_high[1], high)
pivotX_low = float(na)
pivotX_low := nz(pivotX_low[1], low)
pivotX_prev_open = float(na)
pivotX_prev_open := nz(pivotX_prev_open[1])
pivotX_prev_high = float(na)
pivotX_prev_high := nz(pivotX_prev_high[1])
pivotX_prev_low = float(na)
pivotX_prev_low := nz(pivotX_prev_low[1])
pivotX_prev_close = float(na)
pivotX_prev_close := nz(pivotX_prev_close[1])

get_pivot_resolution() =>
    resolution = "M"
    if pivot_time_frame == AUTO
        if timeframe.isintraday
            resolution := timeframe.multiplier <= 15 ? "D" : "W"
        else if timeframe.isweekly or timeframe.ismonthly
            resolution := "12M"
    else if pivot_time_frame == DAILY
        resolution := "D"
    else if pivot_time_frame == WEEKLY
        resolution := "W"
    else if pivot_time_frame == MONTHLY
        resolution := "M"
    else if pivot_time_frame == QUARTERLY
        resolution := "3M"
    else if pivot_time_frame == YEARLY or pivot_time_frame == BIYEARLY or pivot_time_frame == TRIYEARLY or pivot_time_frame == QUINQUENNIALLY or pivot_time_frame == DECENNIALLY
        resolution := "12M"
    resolution

var lines = array.new_line()
var labels = array.new_label()

draw_line(i, pivot, col) =>
    if array.size(arr_time) > 1
        array.push(lines, line.new(array.get(arr_time, i), array.get(pivot, i), array.get(arr_time, i + 1), array.get(pivot, i), color=col, xloc=xloc.bar_time))

draw_label(i, y, txt, txt_color) =>
    if show_labels
        offset = '‏  ‏  ‏  ‏  ‏'
        labels_align_str_left= position_labels == "Left" ? txt + offset : offset + txt
        x = position_labels == "Left" ? array.get(arr_time, i) : array.get(arr_time, i + 1)
        array.push(labels, label.new(x = x, y=y, text=labels_align_str_left, textcolor=txt_color, style=label.style_label_center, color=#00000000, xloc=xloc.bar_time))

traditional() =>
    pivotX_Median = (pivotX_prev_high + pivotX_prev_low + pivotX_prev_close) / 3
    array.push(p, pivotX_Median)
    array.push(r1, pivotX_Median * 2 - pivotX_prev_low)
    array.push(s1, pivotX_Median * 2 - pivotX_prev_high)
    array.push(r2, pivotX_Median + 1 * (pivotX_prev_high - pivotX_prev_low))
    array.push(s2, pivotX_Median - 1 * (pivotX_prev_high - pivotX_prev_low))
    array.push(r3, pivotX_Median * 2 + (pivotX_prev_high - 2 * pivotX_prev_low))
    array.push(s3, pivotX_Median * 2 - (2 * pivotX_prev_high - pivotX_prev_low))
    array.push(r4, pivotX_Median * 3 + (pivotX_prev_high - 3 * pivotX_prev_low))
    array.push(s4, pivotX_Median * 3 - (3 * pivotX_prev_high - pivotX_prev_low))
    array.push(r5, pivotX_Median * 4 + (pivotX_prev_high - 4 * pivotX_prev_low))
    array.push(s5, pivotX_Median * 4 - (4 * pivotX_prev_high - pivotX_prev_low))

fibonacci() =>
    pivotX_Median = (pivotX_prev_high + pivotX_prev_low + pivotX_prev_close) / 3
    pivot_range = pivotX_prev_high - pivotX_prev_low
    array.push(p, pivotX_Median)
    array.push(r1, pivotX_Median + 0.382 * pivot_range)
    array.push(s1, pivotX_Median - 0.382 * pivot_range)
    array.push(r2, pivotX_Median + 0.618 * pivot_range)
    array.push(s2, pivotX_Median - 0.618 * pivot_range)
    array.push(r3, pivotX_Median + 1 * pivot_range)
    array.push(s3, pivotX_Median - 1 * pivot_range)

woodie() =>
    pivotX_Woodie_Median = (pivotX_prev_high + pivotX_prev_low + pivotX_open * 2)/4
    pivot_range = pivotX_prev_high - pivotX_prev_low
    array.push(p, pivotX_Woodie_Median)
    array.push(r1, pivotX_Woodie_Median * 2 - pivotX_prev_low)
    array.push(s1, pivotX_Woodie_Median * 2 - pivotX_prev_high)
    array.push(r2, pivotX_Woodie_Median + 1 * pivot_range)
    array.push(s2, pivotX_Woodie_Median - 1 * pivot_range)

    pivot_point_r3 = pivotX_prev_high + 2 * (pivotX_Woodie_Median - pivotX_prev_low)
    pivot_point_s3 = pivotX_prev_low - 2 * (pivotX_prev_high - pivotX_Woodie_Median)
    array.push(r3, pivot_point_r3)
    array.push(s3, pivot_point_s3)
    array.push(r4, pivot_point_r3 + pivot_range)
    array.push(s4, pivot_point_s3 - pivot_range)

classic() =>
    pivotX_Median = (pivotX_prev_high + pivotX_prev_low + pivotX_prev_close)/3
    pivot_range = pivotX_prev_high - pivotX_prev_low
    array.push(p, pivotX_Median)
    array.push(r1, pivotX_Median * 2 - pivotX_prev_low)
    array.push(s1, pivotX_Median * 2 - pivotX_prev_high)
    array.push(r2, pivotX_Median + 1 * pivot_range)
    array.push(s2, pivotX_Median - 1 * pivot_range)
    array.push(r3, pivotX_Median + 2 * pivot_range)
    array.push(s3, pivotX_Median - 2 * pivot_range)
    array.push(r4, pivotX_Median + 3 * pivot_range)
    array.push(s4, pivotX_Median - 3 * pivot_range)

demark() =>
    pivotX_Demark_X = pivotX_prev_high + pivotX_prev_low * 2 + pivotX_prev_close
    if pivotX_prev_close == pivotX_prev_open
        pivotX_Demark_X := pivotX_prev_high + pivotX_prev_low + pivotX_prev_close * 2
    if pivotX_prev_close > pivotX_prev_open
        pivotX_Demark_X := pivotX_prev_high * 2 + pivotX_prev_low + pivotX_prev_close
    array.push(p, pivotX_Demark_X / 4)
    array.push(r1, pivotX_Demark_X / 2 - pivotX_prev_low)
    array.push(s1, pivotX_Demark_X / 2 - pivotX_prev_high)

camarilla() =>
    pivotX_Median = (pivotX_prev_high + pivotX_prev_low + pivotX_prev_close) / 3
    pivot_range = pivotX_prev_high - pivotX_prev_low
    array.push(p, pivotX_Median)
    array.push(r1, pivotX_prev_close + pivot_range * 1.1 / 12.0)
    array.push(s1, pivotX_prev_close - pivot_range * 1.1 / 12.0)
    array.push(r2, pivotX_prev_close + pivot_range * 1.1 / 6.0)
    array.push(s2, pivotX_prev_close - pivot_range * 1.1 / 6.0)
    array.push(r3, pivotX_prev_close + pivot_range * 1.1 / 4.0)
    array.push(s3, pivotX_prev_close - pivot_range * 1.1 / 4.0)
    array.push(r4, pivotX_prev_close + pivot_range * 1.1 / 2.0)
    array.push(s4, pivotX_prev_close - pivot_range * 1.1 / 2.0)

resolution = get_pivot_resolution()

[sec_open, sec_high, sec_low, sec_close] = request.security(syminfo.tickerid, resolution, [open, high, low, close], lookahead = barmerge.lookahead_on)
sec_open_gaps_on = request.security(syminfo.tickerid, resolution, open, gaps = barmerge.gaps_on, lookahead = barmerge.lookahead_on)

custom_years_divisor = switch pivot_time_frame
    BIYEARLY => 2
    TRIYEARLY => 3
    QUINQUENNIALLY => 5
    DECENNIALLY => 10
    => -1

is_change_years = false 
if custom_years_divisor > 0 and ta.change(time(resolution))
    is_change_years := year % custom_years_divisor == 0



var is_change = false
var uses_current_bar = timeframe.isintraday and kind == WOODIE
var change_time = int(na)
is_time_change = (ta.change(time(resolution)) and custom_years_divisor == -1) or is_change_years
if is_time_change
    change_time := time


if (not uses_current_bar and is_time_change) or (uses_current_bar and not na(sec_open_gaps_on))
    if is_daily_based and custom_years_divisor == -1
        pivotX_prev_open := sec_open[1]
        pivotX_prev_high := sec_high[1]
        pivotX_prev_low := sec_low[1]
        pivotX_prev_close := sec_close[1]
        pivotX_open := sec_open
        pivotX_high := sec_high
        pivotX_low := sec_low
    else
        pivotX_prev_high := pivotX_high
        pivotX_prev_low := pivotX_low
        pivotX_prev_open := pivotX_open
        pivotX_open := open
        pivotX_high := high
        pivotX_low := low
        pivotX_prev_close := close[1]

    if barstate.islast and not is_change and  array.size(arr_time) > 0
        array.set(arr_time, array.size(arr_time) - 1, change_time)
    else
        array.push(arr_time, change_time)

    if kind == TRADITIONAL
        traditional()
    else if kind == FIBONACCI
        fibonacci()
    else if kind == WOODIE
        woodie()
    else if kind == CLASSIC
        classic()
    else if kind == DEMARK
        demark()
    else if kind == CAMARILLA
        camarilla()

    if array.size(arr_time) > look_back
        if array.size(arr_time) > 0
            array.shift(arr_time)
        if array.size(p) > 0 and p_show
            array.shift(p)
        if array.size(r1) > 0 and s1r1_show
            array.shift(r1)
        if array.size(s1) > 0 and s1r1_show
            array.shift(s1)
        if array.size(r2) > 0 and s2r2_show
            array.shift(r2)
        if array.size(s2) > 0 and s2r2_show
            array.shift(s2)
        if array.size(r3) > 0 and s3r3_show
            array.shift(r3)
        if array.size(s3) > 0 and s3r3_show
            array.shift(s3)
        if array.size(r4) > 0 and s4r4_show
            array.shift(r4)
        if array.size(s4) > 0 and s4r4_show
            array.shift(s4)
        if array.size(r5) > 0 and s5r5_show
            array.shift(r5)
        if array.size(s5) > 0 and s5r5_show
            array.shift(s5)
    is_change := true
else
    if is_daily_based and custom_years_divisor == -1
        pivotX_high := math.max(pivotX_high, sec_high)
        pivotX_low := math.min(pivotX_low, sec_low)
    else
        pivotX_high := math.max(pivotX_high, high)
        pivotX_low := math.min(pivotX_low, low)

if barstate.islast and array.size(arr_time) > 0 and is_change
    is_change := false
    if array.size(arr_time) > 2 and custom_years_divisor > 0
        last_pivot_time = array.get(arr_time, array.size(arr_time) - 1)
        prev_pivot_time = array.get(arr_time, array.size(arr_time) - 2)
        estimate_pivot_time = last_pivot_time - prev_pivot_time
        array.push(arr_time, last_pivot_time + estimate_pivot_time)
    else
        array.push(arr_time, time_close(resolution))

    for i = 0 to array.size(lines) - 1
        if array.size(lines) > 0
            line.delete(array.shift(lines))
        if array.size(lines) > 0
            label.delete(array.shift(labels))

    for i = 0 to array.size(arr_time) - 2
        if array.size(p) > 0 and p_show
            draw_line(i, p, p_color)
            draw_label(i, array.get(p, i), "P", p_color)
        if array.size(r1) > 0 and s1r1_show
            draw_line(i, r1, s1r1_color)
            draw_label(i, array.get(r1, i), "R1", s1r1_color)
        if array.size(s1) > 0 and s1r1_show
            draw_line(i, s1, s1r1_color)
            draw_label(i, array.get(s1, i), "S1", s1r1_color)
        if array.size(r2) > 0 and s2r2_show
            draw_line(i, r2, s2r2_color)
            draw_label(i, array.get(r2, i), "R2", s2r2_color)
        if array.size(s2) > 0 and s2r2_show
            draw_line(i, s2, s2r2_color)
            draw_label(i, array.get(s2, i), "S2", s2r2_color)
        if array.size(r3) > 0 and s3r3_show
            draw_line(i, r3, s3r3_color)
            draw_label(i, array.get(r3, i), "R3", s3r3_color)
        if array.size(s3) > 0 and s3r3_show
            draw_line(i, s3, s3r3_color)
            draw_label(i, array.get(s3, i), "S3", s3r3_color)
        if array.size(r4) > 0 and s4r4_show
            draw_line(i, r4, s4r4_color)
            draw_label(i, array.get(r4, i), "R4", s4r4_color)
        if array.size(s4) > 0 and s4r4_show
            draw_line(i, s4, s4r4_color)
            draw_label(i, array.get(s4, i), "S4", s4r4_color)
        if array.size(r5) > 0 and s5r5_show
            draw_line(i, r5, s5r5_color)
            draw_label(i, array.get(r5, i), "R5", s5r5_color)
        if array.size(s5) > 0 and s5r5_show
            draw_line(i, s5, s5r5_color)
            draw_label(i, array.get(s5, i), "S5", s5r5_color)

馬努

Answer 1

這里有四個運營商需要了解。

1. =在聲明變量時使用。
2. :=用於為已聲明的變量分配新值。
3. []稱為歷史引用運算符，用於訪問變量的歷史數據。 例如， close[1]返回一根柱線之前的收盤價。
4. nz() ：將 NaN 值替換為系列中的零（或給定值）。

現在，讓我們看看下面的代碼：

pivotX_prev_low = float(na)
pivotX_prev_low := nz(pivotX_prev_low[1])

pivotX_prev_low = float(na) ：聲明一個名為pivotX_prev_low的新float類型變量，並將其na作為初始值。

pivotX_prev_low:= nz(pivotX_prev_low[1]) ：現在將pivotX_prev_low的先前值分配給pivotX_prev_low 。

要理解最后一部分，請知道您的腳本將在每個柱上執行。 當您想在 go 從一個小節到另一個小節時獲得一些恆定的信息時，這就是您（過去）的做法。 因為它會不斷用之前的值更新它的值，所以它的值將保持不變。

最后，使用nz()是因為對於圖表的第一個柱，沒有歷史數據。 [1]將返回NaN （請記住，它是第一個欄，因此沒有[1] ），這可能會打亂您的計算。

現在，這是執行此操作的傳統方式。 從//@version=4開始，您可以為此目的使用var關鍵字。

var pivotX_prev_low = float(na)

var關鍵字聲明一個變量並且只初始化一次。 這允許變量的值從初始化或最后分配的那一刻起自動保存在柱之間。

因此，在您執行pivotX_prev_low:= newVal ，它將保持其與之前柱的值。