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