average with sorting

[augustus]

I would like to calculate an average as follows :
1. Take the daily Hi-Lo-Range of the last 20 days.
2. Sort this values ascending in sequence.
3. Delete the highest and the lowest 5 values starting from the lowest.
4. Compute from the remaining 10 values an average and stddev.
5. Plot the average on an 5 minute chart.

Could somebody help with step 2 and 3?

Thanks

[ckryza]

Augustus:

The following function will calculate the two values and return them in an array:

function CustomAverageRange( nBars ) {
var x=0;
var nRemove     = null;
var nMin         = null;
var nMax         = null;
var nPrd         = null;
var aVals         = null;
var nAvg         = 0;
var nSumAvg        = 0;

    //smallest value you can pass to this function is 4
    if ( nBars<4 ) nBars = 4;


    nRemove = Math.floor( nBars/4 );
    nMin = nRemove;
    nMax = nBars-nRemove;
    nPrd = nMax-nMin;
    aVals = new Array( nBars );
    

    //gather the range values over the specified period
    while( x<nBars ) {
        aVals[x] = ( high(-x)-low(-x) );
        x++;
    }
    
    //sort the array 
    aVals.sort();
    
    //calculate the average. We are ignoring 1/4 of the lower values
    //and 1/4 of the higher values
    x=nMin;
    while( x<nMax ) {
        nAvg += aVals[x];
        x++;
    }
    nAvg /= nPrd;
    
    
    //calculate the standard deviation using the same process
    x=nMin;
    while( x<nMax ) {
        nSumAvg += Math.pow( ( aVals[x]-nAvg ), 2 );
        x++;
    }
    nSumAvg /= nPrd;
    nStdDev = Math.sqrt( nSumAvg );
    
    return new Array( nAvg, nStdDev );
} 

You would just call it from within the main() function as needed. Remember that the return value will be an array so you need to treat it as such:


MyVal = CustomAverageRange( 20 );

//Average will be in array index 0 and standard deviation will be
//in array index 1

theAverage = MyVal[0];
theStdDev = MyVal[1];

Chris

[augustus]

Hi Chris,

many thanks for your help.

As aVals.sort() was not sorting all values sequential, i added the function SortMe from one of your older VP-codes.

function SortMe( arg1, arg2 ) {
if (arg1<arg2) {
return( -1 )
}
else {
return( 1 );
}
}

It now works with aVals.sort(SortMe) .

Regards