Accumulation Swing Index (ASI)

[eSignal]

File Name: AccumSwingIndex.efs

Description:
Accumulation Swing Index (ASI)

Formula Parameters:
Daily Limit : 10000

Notes:
The Accumulation Swing Index is a cumulative total of the Swing Index.
The Accumulation Swing Index was developed by Welles Wilder.
The SwingIndex function was developed to help cut through the maze of
Open, High, Low and Close prices to indicate the real strength and direction
of the market. The Swing Index function looks at the Open, High, Low and
Close values for a two-bar period. The theory is that there are four cross-bar
and one intra-bar comparisons that are strong indicators of an up or down day.
The Swing Index returns a number between -100 and 100. If the factors point toward
an up day, then the function value will be positive and vice versa. In this way,
the Swing Index gives us definite short-term swing points, and it can be used to
supplement other methods as a breakout indicator. A breakout is indicated when the
value of the Accumulation Swing Index (ASI) exceeds the ASI value on the day when a
previous significant High Swing Point was made. A downside breakout is indicated when
the value of the ASI drops below the ASI value on a day when a previous significant
low swing point was made.
Since only futures have a relative daily limit value, this function only makes sense
when applied to a futures contract. If you use this function and it only plots a zero
flat line, check the Daily Limit value.


Download File:
AccumSwingIndex.efs



EFS Code:

/*********************************
Provided By:  
    eSignal (Copyright c eSignal), a division of Interactive Data 
    Corporation. 2009. All rights reserved. This sample eSignal 
    Formula Script (EFS) is for educational purposes only and may be 
    modified and saved under a new file name.  eSignal is not responsible
    for the functionality once modified.  eSignal reserves the right 
    to modify and overwrite this EFS file with each new release.

Description:        
    Accumulation Swing Index (ASI)
    
Version:            1.0  05/13/2009
    
Formula Parameters:                     Default:
    Daily Limit                         10000
    
Notes:
    The Accumulation Swing Index is a cumulative total of the Swing Index. 
    The Accumulation Swing Index was developed by Welles Wilder.
    The SwingIndex function was developed to help cut through the maze of 
    Open, High, Low and Close prices to indicate the real strength and direction 
    of the market. The Swing Index function looks at the Open, High, Low and 
    Close values for a two-bar period. The theory is that there are four cross-bar 
    and one intra-bar comparisons that are strong indicators of an up or down day.
    The Swing Index returns a number between -100 and 100. If the factors point toward 
    an up day, then the function value will be positive and vice versa. In this way, 
    the Swing Index gives us definite short-term swing points, and it can be used to 
    supplement other methods as a breakout indicator. A breakout is indicated when the 
    value of the Accumulation Swing Index (ASI) exceeds the ASI value on the day when a 
    previous significant High Swing Point was made. A downside breakout is indicated when 
    the value of the ASI drops below the ASI value on a day when a previous significant 
    low swing point was made.
    Since only futures have a relative daily limit value, this function only makes sense 
    when applied to a futures contract. If you use this function and it only plots a zero 
    flat line, check the Daily Limit value. 
**********************************/
var fpArray = new Array();
var bInit = false;

function preMain() {
    setPriceStudy(false);
    setShowCursorLabel(true);
    setShowTitleParameters( false );
    setStudyTitle("Accum Index"); 
    setCursorLabelName("Accum Index");
    var x = 0;
    fpArray[x] = new FunctionParameter("DailyLimit", FunctionParameter.NUMBER);
    with(fpArray[x++]) {
        setName("Daily Limit");
        setLowerLimit(1);
        setDefault(10000);
    }    
}

var xAccumIndex = null;

function main(DailyLimit) {
var nAccumIndex = 0;    
    if (bInit == false) {
        xAccumIndex = efsInternal("Calc_ASI", DailyLimit);
        bInit = false;
    }
    nAccumIndex = xAccumIndex.getValue(0);
    if (nAccumIndex == null) return;
    return nAccumIndex;
}

var xOpen = null;
var xClose = null;

function Calc_ASI(nDailyLimit) {
var K = 0;
var R = 0;
var AbsHighClose = 0;
var AbsLowClose = 0;
var AbsCloseOpen = 0;
var SwingIndex = 0;
var ASI = ref(-1);
    if (xOpen == null) xOpen = open();
    if (xClose == null) xClose = close();
    var h0 = high(0);
    var l0 = low(0);
    var o0 = xOpen.getValue(0);
    var o1 = xOpen.getValue(-1);
    var c0 = xClose.getValue(0);
    var c1 = xClose.getValue(-1);
    if (c1 == null) return;
    AbsHighClose = Math.abs(h0 - c1);
    AbsLowClose = Math.abs(l0 - c1);
    AbsCloseOpen = Math.abs(c1 - o1);
    if (AbsHighClose >= AbsLowClose){
        K = AbsHighClose;
        if (AbsHighClose >= (h0 - l0)) R = AbsHighClose - 0.5 * AbsLowClose + 0.25 * AbsCloseOpen;
        else R = (h0 - l0) + 0.25 * AbsCloseOpen;
    } else {
        K = AbsLowClose;
        if (AbsLowClose >= (h0 - l0)) R = AbsLowClose - 0.5 * AbsHighClose + 0.25 * AbsCloseOpen;
        else R = (h0 - l0) + 0.25 * AbsCloseOpen;
    }
    if (R != 0)    
        SwingIndex = 50 * (((c0 - c1) + 0.50 * (c0 - o0) + 0.25 * (c1 - o1)) / R ) * K / nDailyLimit;
    else
        SwingIndex = 0;
    ASI += SwingIndex;
    return ASI;
}