Calculations (Advanced)
Calculation with previous check results
For calculation checks, previous check results can also be used within the checklist. This is possible for results of numerical and calculation checks.
First of all, it is important to store checkidentifier for those checks that are to be used for the calculation. This is possible via the general check settings.
Any feature (standard or custom) can be used for calculation and the desired number of input values can be selected.
After that, the designation of the values as well as the test identification previously stored for the respective checks must be specified. A default value can optionally be defined, which is used if the corresponding check has not (yet) been executed. This value can also be overwritten manually. If there is no default value, a value must be entered manually.
Executing the checklist
When executing the checklist, the measured values can be entered as usual. The calculation with the previous check results automatically accesses the previous check results as soon as they have been entered.
If the check, that should have been used as the second value for the calculation, was filled in later after all, the calculation check can be reloaded afterwards with this icon:
If a check that is used for calculation was not executed, the result can also be entered manually. This is indicated by the information "No result at referred check".
If a default value is defined, the message "No result at referred check, default value was used" appears. The default value can also be overwritten.
Custom calculations
The "Calculation" check type is also user-defined. When creating a user-defined calculation check, several input values can be defined, which can then be used in a user-defined formula. The rules of mathematics such as power goes before point calculation, point before line calculation as well as the bracket rules are taken into account.
As also possible in the numerical as well as the calculation check, there is the option to define a lower tolerance limit, a lower control limit, a target value, an upper control limit and an upper tolerance limit for the validation of a check.
Formula
The formula must be entered mathematically correct. A template for this is also displayed when creating the check: ((#value_1# + #value_2#) / #value_1#) * 100
Input of the check and options for the calculation:
The formula can be tested via the check preview, which is started via the context menu. Any form errors can thus be detected and corrected.
Successful check in preview mode:
Error messages
The check fails if the formula is wrong, for example if a bracket is set incorrectly or the calculation is by 0.
Error message Form error in preview mode:
Error message Value by zero in preview mode:
Visualization of the calculation
When displaying checklists (in web and PDF protocols), only the result is displayed and not the stored formula. If this is desired, the formula can be additionally stored in the description.
Comparison of check in PDF protocol: 2.1 with description and 2.2 without description
The following calculation types are possible:
+ | Addition Operator eg. 2+3 results 5 | pi | Math constant pi returns 3.14 |
- | Subtraction Operator eg. 2-3 results -1 | e | Math constant e returns 2.71 |
/ | Division operator eg 3/2 results 1.5 | C | Combination operator eg. 4C2 returns 6 |
\ | Multiplication Operator eg. 23 results 6 | P | Permutation operator eg. 4P2 returns 12 |
Mod | Modulus Operator eg. 3 Mod 2 results 1 | ! | factorial operator eg. 4! returns 24 |
( | Opening Parenthesis | log | logarithmic function with base 10 eg. log 1000 returns 3 |
) | Closing Parenthesis | ln | natural log function with base e eg. ln 2 returns .3010 |
Sigma | Summation eg. Sigma(1,100,n) results 5050 | pow | power function with two operator pow(2,3) returns 8 |
Pi | Product eg. Pi(1,10,n) results 3628800 | ^ | power operator eg. 2^3 returns 8 |
n | Variable for Summation or Product | root | runderroot function root 4 returns 2 |
Example of the use of user-defined calculations
Percentage deviation from the average of the samples
Creation of user-defined calculation and formula creation
Overview of calculation after formula creation
Preview and verification of the formula