Rounding Methodology
The Sigmafine Data Reference implements a configurable rounding methodology to satisfy any calculation standard or any specific rounding specification. Since these standards are revised every few years, the implementation of this methodology allows you to specify the rounding for each calculation method and to update this configuration as needed. In addition, this functionality is helpful for implementing specific rounding requirements established for contractual reasons or for guaranteeing consistency of calculated values. This is especially important when these values are reviewed by third party programs that might follow different standards.
If you do not require any rounding and need to preserve all precision, it is not necessary to make any changes to the AF/Sigmafine database. This is the Case if you follow the Manual of Petroleum Measurement Standards, published in 2004, that specifies “no rounding of initial or intermediate values.”
There is a minimal requirement for the execution of this functionality. The SF_Rounding Element must be created to specify if the rounding is to be performed, and the level of rounding to use for each variable. The following figure illustrates the required Attributes of this element.
The Rounding Attribute specifies whether rounding is done, which means that it is possible to turn off rounding at any time. If the value for this Attribute is TRUE, the Sigmafine Data Reference makes the calculations using the rounding factor.
The values of the Rounding Attributes specify how many decimal places are retained during the calculations. The rounding calculation implements the recommended method of the Manual of Petroleum Measurement Standards for the display of final calculated values.
Rounding Methodology Usage
| Rounding to... | Value | Typical Use |
|---|---|---|
| Nearest integer value | 1 | Rounding temperatures for the CTSh calculation. |
| Two decimal places | 0.01 | Rounding volumes when computing NetVolume. |
| Five decimal places | 0.00001 | Rounding values of corrections factors, such as VCF and CTSh. |
| N decimal places | 0.0…01 {N-1 zeros after the period} | Any special rounding requirement. |
The factors only apply to the internal units of measure of the Sigmafine calculation, which are the following:
- Volume - bbl
- Mass - lb
- Density - SG or API (depending on the calculation)
- Temperature - °F
Rounding for any other unit of measures must be scaled to the internal unit of measure.
For additional information on the rounding function, see Round Function.