SpreadingPrecision

Use the SpreadingPrecision parameter to increase or decrease the margin of error for spreading calculations.

Parameter type: optional, dynamic

Floating point arithmetic on computers is not 100% precise. When a computer calculates very small numbers, a margin of error is applied to the calculation. If the computer adds a set of numbers, and the resulting sum is close to the target value within the margin of error, the sum is considered accurate.

The margin of error for certain Cognos® TM1® calculations is controlled through the SpreadingPrecision parameter. The default value is SpreadingPrecision=1e-8. This value is used in the following spreading scenarios:

Spreading from a consolidated cell.
Spreading in leaf cells whose consolidated value has a hold applied.

Spreading from a Consolidation

When you execute a proportional data spread from a consolidated cell, Cognos TM1 writes the numbers to each cell in the range, and rolls up the total to recalculate the consolidation. The total of all cells in the consolidation is then compared to the original value you provided for the spread function. The total might be different from the target value because of the rules applied to the n-level elements or the consolidated cell itself.

If the rules are such that the resultant value does not match the spread desired value, an error will be generated and the spread operation will not be done.

If SpreadingPrecision=1e-8, the total calculated by Cognos TM1 for the consolidation must be within 0.000001% of the target value (99.999999% accurate), or Cognos TM1 displays an error. An error of more than US$0.01 on a consolidated spread of US$1,000,000 results in an error.

You can increase or decrease the margin of error for these types of calculations using the SpreadingPrecisionparameter.

The following examples include valid values for the SpreadingPrecision parameter:

SpreadingPrecision=1e-4
SpreadingPrecision=1e-8
SpreadingPrecision=1e-10
SpreadingPrecision=1e-12

Spreading and Consolidation Holds

The SpreadingPrecision parameter also has an effect under these conditions:

When you spread values to some leaf cells that roll up into a consolidation
A consolidation with a hold applied to it

For example, suppose you have the consolidation Q1 with values Jan, Feb, and Mar.

If Q1- has a consolidated hold applied, and you spread values to Jan and Feb, Cognos TM1 does the following:

Applies the spreading to Jan and Feb.
Adjusts Mar.
Adds the three n-level elements together.
Compares the sum of the n-level elements to the value of Q1.

If the sum is accurate to within the margin of error specified by the SpreadingPrecision parameter, the spread succeeds. If the sum falls outside the margin of error specified by the SpreadingPrecision parameter, Cognos TM1 generates an error.