Maintaining Rounding Tables

Overview

Rounding tables are used to round and format numerical data for a report, with the rounding based upon the analytical detection limit, a given picture format and a concept referred to as nice numbers conversion. Rounding is based on ISO Rounding Rules.

Rounding codes are assigned to numerical analytes of schemes, and are used when the analyte is included in a report that requires rounding.

Each rounding table comprises a grid of values that are used to determine the rounding method.

This process is pertinent to laboratory managers who configure certificate reports for the laboratory.

Analyte-based Rounding Tables

It is possible to have an analyte with a rounding table in which the Picture is either PASS or FAIL. This still requires the entry of a numeric value where the numeric value is used to interpret the string using normal rounding rules.

Using tilde (~) in Picture Masks

The use of tilde (~) in the mask of the picture represents the number of significant figures in the case of a whole number. That is:

• XXX~XXX => 4 significant figures (x 10 exp -4)
• XXsXXXX~ => 1 significant figures (x 10 exp -1)
• ~XXXXXX => 7 significant figure (x 10 exp -7)
• If the picture has a decimal point in it, then this are used as the number of decimal places to round to, and the tilde (~) has no significance, except to tell CCLAS that this must be ISO rounded. That is:
• XXXXXX.X~ => 2 significant figures (x 10 exp 2)
• XXX.XXXXX~ => 6 significant figures (x 10 exp 6)
• X.XXXXXXX~ => 8 significant figures (x 10 exp 8)

Once the significant figures are in place, the rounding procedure works as follows:

• It checks whether the next number after the position of the desired number of significant figures is a 5.
• If the number is not a 5, it rounds as per normal rounding, for example, it rounds up for a number > 5; and rounds down for a number < 5.
• If the number is a 5, and the digit in the position preceding this number is even, it converts the 5 to a 4, and then rounds as per normal, that is, it does not change the number of the digit before it.
• If the number is a 5, and the digit in the position preceding this number is odd, it rounds as per normal. This increases the digit before it by 1.

Example: Picture X.X~, to 2 significant figures.

• Digit after desired significant figures is not a 5
  • 1.389 => 1.39
  • 1.324 => 1.32
• Digit after desired significant figures is a 5
  • 1.345 => 1.34
  • 1.335 => 1.34
  • 1.365 => 1.36
  • 1.375 => 1.38

Example: Picture X~X, to -2 significant figures.

• 125 => 124
• 135 => 135

Process

Rounding tables are maintained using the Setup application. You need specific rights to have visibility to this application.

Rounding tables are maintained using simple SCRUD (search, create, review, update, delete) functionality under the Setup » Rounding codes node. You need specific rights to have visibility to this node.

Maintain rounding tables

Access a custom form from the Rounding table node