Calculating standard deviation of the sample not the population-Error The value entered does not match the format of the field [StdDev4]

Follow up onneed a custom calculation script to calculate standard deviation since I posted there and didn't get a response

I need to calculate the standard deviation of the sample not the population so how do I change the document JavaScript? Also, when I don't have any variation in my 10 values, I get a warning: JavaScript Window that says The value entered does not match the format of the field [StdDev4]

Here are the Document JavaScripts

Fields:

function GetField(oDoc, cField)

{

var oField = oDoc.getField(cField);

if(oField == null)

{

  app.alert("Error accessing field \"" + cField + "\"!", 1, 0)

}

return oField;

}

StdDev:

function standardDeviation(values)
{
// compute the standard deviation from an array of vlaues;
// compute the average of the vaues;
var stdDev = "";
  var avg = average(values);
  if(avg != "")
  {
// compute the squared difference of the values and the average;
  var squareDiffs = values.map(function(value){
    var diff = value - avg;
    var sqrDiff = diff * diff;
    return sqrDiff;
  });
  // average the squared differences;
  var avgSquareDiff = average(squareDiffs);
    stdDev = Math.sqrt(avgSquareDiff);
    } // end avg not null;
  return stdDev;
}

function average(data)
{
// compute the average of an array of values;
//sum the values in the array;
  var sum = data.reduce(function(sum, value){
    return sum + value;
  }, 0);
  // compute the average of the sum of the values if number of array elements is not 0;
  var avg = '';
  if(data.length > 0)
  {
  var avg = sum / data.length;
  }
  return avg;
  }

function sum(value)
{
// sum an array of values;
var Sum = value.reduce(function(Sum, value){
    return Sum + value;
  }, 0);
return Sum;
}

Custom Calculation Script:

var MyValues = new Array();

var MyFields = new Array("AdjustedResult5.1", "AdjustedResult5.2","AdjustedResult5.3", "AdjustedResult5.4", "AdjustedResult5.5", "AdjustedResult5.6", "AdjustedResult5.7", "AdjustedResult5.8", "AdjustedResult5.9", "AdjustedResult5.10" );

var oField;

var nField;

for(var i = 0; i < MyFields.length; i++)

{

nField = '';

nField = GetField(this, MyFields).valueAsString;

if(nField != "") MyValues.push(Number(nField));

}

event.value = standardDeviation(MyValues);

--------------------------------------------------------------------------------------------------------------------

I  have also tried this for the standard deviation of the sample:

var Ravg = Number(this.getField("AvgAdjResult.1.0").valueAsString); 

var Rsum = 0; 

var Rn = 0; 

for (var i=1; i<=10; i++) { 

var Rv = this.getField("AdjustedResult1."+i).valueAsString; 

if (Rv!="") { 

Rsum+=Math.pow((Number(Rv)-Ravg),2);

Rn++; 

} 

} 

if (Rn==0 || Rn==1) event.value = ""; 

else event.value = Math.sqrt(Rsum / (Rn-1));

However, I want the cell to stay blank unless there is an average calculated. Also we have low variability in our 10 replicates so the standard deviation can be zero, but I get the error mentioned above: The value entered does not match the format of the field [StdDev4] because it doesn't like to take the square root of zero. How do I make this error disappear, but the cell still have a numeric value of 0.000000?

I tried changing it to this:

var Ravg = Number(this.getField("AvgAdjResult.1.0").valueAsString);  
var Rsum = 0;  
var Rn = 0;  
for (var i=1; i<=10; i++) {  
var Rv = this.getField("AdjustedResult1."+i).valueAsString;  
if (Rv!="") {  
Rsum+=Math.pow((Number(Rv)-Ravg),2); 
Rn++;  
}  
} 

var b =  +getField("Result1.10").value; 
var c =  Rsum / (Rn-1);
if (b==0) event.value = "";  
else if (c==0) event.value = 0.000000;
else event.value = Math.sqrt (c);

but then I don't get a result at all.

Field names are shown in bold below and an example of the data is below as well