Return Input Number to Arbitrary Precision

 Function ChangePrecision(vNum, vPrecision, vPreserveSign)
    Variable vNum       //input number to operate on
    Variable vPrecision //output precision (number of decimal places)
    Variable vPreserveSign  //1 == retain sign of input
   
    Variable vReturn
    Variable vExponent
    Variable vMantissa
    Variable vPwr
    Variable vSign
   
//this will cause an error with the log fcn
    if(vNum == 0)
        return 0
    endif
   
//precision less than 0 makes no sense
    if(vPrecision < 0)
        return vNum
    endif
   
//store sign of input and ensure input is positive
    vSign = sign(vNum)
    vNum = abs(vNum)

//get mantissa of number   
    vExponent = floor(log(vNum))
    vPwr =  (1 *10^vExponent)
    vMantissa = vNum / vPwr

//change mantissa to desired precision 
    vMantissa = (round(vMantissa * 10^vPrecision)) / 10^vPrecision
    vReturn = (vMantissa) * vPwr

//if requested, change to original sign
    if(vPreserveSign == 1)
        vReturn *= vSign
    endif

//  Print log(vNum),vExponent, vmantissa, vPwr, vSign
   
    return vReturn
End

Function ArbPrec(vNum, vPrecision, vPreserveSign)
    Variable vNum       //input number to operate on
    Variable vPrecision //output precision (number of decimal places)
    Variable vPreserveSign  //1 == retain sign of input
   
    Variable vSign
    Variable vOutput
    String sNum
   
//precision less than 0 makes no sense
    if(vPrecision < 0)
        return vNum
    endif
   
//store sign of input and ensure input is positive
    vSign = sign(vNum)
    vNum *= vSign //same as abs(vNum)
   
//change to desired precision  
    APMath/N=(vPrecision) sNum = vNum
    vOutput = str2num(sNum)
   
//if requested, change to original sign
    if(vPreserveSign == 1)
        vOutput *= vSign
    endif
   
    return vOutput
end