Symmetric difference: symdiff
Syntax
symdiff ( ds1, ds2 )
Input parameters
ds1 |
the first Data Set in the difference |
ds2 |
the second Data Set in the difference |
Semantics for scalar operations
This operator cannot be applied to scalar values.
Input parameters type
ds1, ds2
dataset
Result type
result
dataset
Additional Constraints
The operand Data Sets have the same Identifier, Measure and Attribute Components.
Behaviour
The operator implements the symmetric set difference between functions (i.e. Data Sets), interpreting the Data Points of the input Data Sets as the elements in the operand Sets. The operator returns one Data Set, with the same Identifier, Measure and Attribute Components as the operand Data Sets, containing the Data Points that appear in the first Data Set but not in the second and the Data Points that appear in the second Data Set but not in the first one.
Data Points are compared to one another by Identifier Components. For symdiff (ds1, ds2), the resulting Data Set contains all the Data Points dp1 contained in ds1 for which there is no Data Point dp2 in ds2 with the same values for homonym Identifier components and all the Data Points dp2 contained in ds2 for which there is no Data Point dp1 in ds1 with the same values for homonym Identifier Components.
The operator has the typical behaviour of the “Behaviour of the Set operators” (see the section “Typical behaviours of the ML Operators”).
The automatic Attribute propagation is not applied.
Examples
Given the operand datasets DS_1 and DS_2:
Input DS_1 (see structure)
Id_1 |
Id_2 |
Id_3 |
Id_4 |
Me_1 |
|---|---|---|---|---|
2012 |
B |
Total |
Total |
1 |
2012 |
G |
Total |
Total |
2 |
2012 |
F |
Total |
Total |
3 |
2012 |
M |
Total |
Total |
4 |
2012 |
I |
Total |
Total |
5 |
2012 |
S |
Total |
Total |
6 |
Input DS_2 (see structure)
Id_1 |
Id_2 |
Id_3 |
Id_4 |
Me_1 |
|---|---|---|---|---|
2011 |
B |
Total |
Total |
1 |
2012 |
G |
Total |
Total |
2 |
2012 |
F |
Total |
Total |
3 |
2012 |
M |
Total |
Total |
4 |
2012 |
I |
Total |
Total |
5 |
2012 |
S |
Total |
Total |
6 |
Example 1
DS_r := symdiff ( DS_1, DS_2 );
results in (see structure):
Id_1 |
Id_2 |
Id_3 |
Id_4 |
Me_1 |
|---|---|---|---|---|
2012 |
B |
Total |
Total |
1.0 |
2011 |
B |
Total |
Total |
1.0 |