This function checks floating point numbers for equality, by using an approximation formula and a fixed precision by constant 1.0E-12 (pico)
LGF_CompareLReal (FC) | ||||||||
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LReal | valueA | Ret_Val | Bool | |||||
LReal | valueB | |||||||
Identifier | Data type | Description |
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valueA | LReal | First LREAL number to be compared. |
valueB | LReal | Second LREAL number to be compared. |
Identifier | Data type | Description |
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Ret_Val | Bool | FALSE: not equal TRUE: approximately the same |
The comparison of the LREAL numbers is based on an fixed accuracy of 1.0E-12. The difference between the two input values must be smaller than the PRECISION
accuracy multiplied by one of the two input values.
Equation:
result := FALSE OR ((#valueA = 0.0) AND (ABS(#valueB) <= #precision)) OR ((#valueB = 0.0) AND (ABS(#valueA) <= #precision)) OR (ABS(valueA - valueB) <= (PRECISION * ABS(valueA));LGF_CompareLRealByPrecision
.Version & Date | Change description | |
---|---|---|
01.00.00 | Siemens Industry Online Support | |
13.01.2017 | First released version | |
01.00.01 | Siemens Industry Online Support | |
17.08.2018 | Upgrade: TIA V15 Update 2 | |
01.00.02 | Siemens Industry Online Support | |
23.11.2018 | Upgrade: TIA V15.1 | |
01.00.03 | Simatic Systems Support | |
03.06.2019 | Refactoring and performance improvment Delete Error and Status there is no need for, because of changed / adjusted algorithm add eno handling | |
03.00.00 | Simatic Systems Support | |
23.04.2020 | Set version to V3.0.0, harmonize the version of the whole library | |
03.00.01 | Simatic Systems Support | |
19.01.2020 | Insert documentation | |
03.00.02 | Simatic Systems Support | |
21.12.2023 | Fix compare error if one value is exactly zero |