Determine Data History
Use this tool to get statistical information about the history of your processed data.
Execution Behavior
The behavior of this tool regarding the execution differs from the default behavior. Usually a MERLIC tool is executed in the following cases:
- The MERLIC Vision App is explicitly executed in continuous mode.
- The MERLIC Vision App is explicitly executed in "Run Once" mode.
- A MERLIC Vision App with the tool is opened in the MERLIC Creator.
- A parameter value of the tool has been changed in the MERLIC Creator.
However, the tool "Determine Data History" is only executed in the following cases:
- The MERLIC Vision App is explicitly executed in continuous mode.
- The MERLIC Vision App is explicitly executed in "Run Once" mode.
This ensures that no data will be added to the buffer when loading an MVApp or changing a parameter value of the tool.
Parameters
Basic Parameters
Data Value:
This parameter defines the data values that are checked. You can either connect the parameter to an appropriate result of a previous tool and use its value as input or you can define the value manually at the connector.
Buffer Size:
This parameter allows you to adjust the "Buffer Size" to define the number of data values which should be stored for the data history. As a default, this value is set to 1000.
Additional Parameters
Lower Bound:
This parameter defines the minimum value that is allowed for the "Data Value" to be classified as a good value. In combination with "Upper Bound" it can be used to define the range of the values that are classified as good. The parameter is set to 1 by default. You can change the value from −1000000.0 up to the value defined in "Upper Bound" using the slider.
If the processed "Data Value" lies within the defined range for the good values, it is included in the result "Percent Good", otherwise in the result "Percent Bad".
Upper Bound:
This parameter defines the maximum value that is allowed for the "Data Value" to be classified as a good value. In combination with "Lower Bound" it can be used to define the range of the values that are classified as good. The parameter is set to 1 by default. You can change the value from the value defined in "Lower Bound" to up to 1000000.0 using the slider.
If the processed "Data Value" lies within the defined range for the good values, it is included in the result "Percent Good", otherwise in the result "Percent Bad".
Reset:
This parameter enables you to reset the data history of the values that have been processed so far. It is defined as a Boolean value and set to 0 by default. This means that no result is reset. If "Reset" is set to 1 all results are reset and the collected information of the buffered data is lost. This can not be undone. A reset is especially needed if a new or different "Data Value" is used. Else the resulting information of the previous data is not removed from the results. The parameter is automatically set back to 0 after a reset.
Smoothing:
This parameter defines a factor for how much the buffered data are smoothed. The smoothing is determined with a Gaussian function. The value is defined as a real number and set to 2 by default. The smoothed data are returned in "Processed Buffer Data". You can set a smoothing factor between 0 and 10 at the corresponding connector. To disable the smoothing of the buffered data, you have to set the parameter value to 0. The resulting data are then returned without any smoothing in "Processed Buffer Data".
Sample Limit:
This parameter defines a limit for the amount of data that is returned as "Processed Buffer Data", i.e., buffered data being smoothed. If the buffered data exceeds the value defined in "Sample Limit", the data are sampled to as many equidistant values as defined in "Sample Limit". The parameter is set to 1 000 by default. This means, that in case the buffered data exceed the value 1 000, they are sampled to 1 000 equidistant values and returned in "Processed Buffer Data".
A sampling can only be performed if the "Sample Limit" is lower than the value defined for the "Buffer Size" and the actual amount of buffered data exceeds the value defined in "Sample Limit". With the default settings of the tool, the amount of data never exceeds the defined "Sample Limit" because the "Buffer Size" is also set to 1 000 by default. Thus, the sampling is disabled for the default settings. However, you may change the value for the "Sample Limit" at the corresponding connector to a value between 1 - 100 000. For example, if you select a "Sample Limit" of 100 and the amount of buffered data is 1 000, the data are sampled to 100 equidistant values, i.e., each 10th value (1 000 / 100) is returned in "Processed Buffer Data". This enables you to reduce the number of buffer values that are returned.
Results
Basic Results
Average:
This result is the calculated average of the data passed in "Data Value". The result is returned as real number.
Median:
The result is the calculated median of the data passed in "Data Value". The result is returned as real number.
Minimum:
The result is the minimum of the data passed in "Data Value". The result is returned as real number.
Maximum:
The result is the maximum of the data passed in "Data Value". The result is returned as real number.
Standard Deviation:
The result is the calculated standard deviation of the data passed in "Data Value". The result is returned as real number.
Buffer Data:
This result returns all processed data passed in "Data Value" in form of a tuple.
Tool State:
"Tool State" returns information about the state of the tool and thus can be used for error handling. Please see the topic Tool State Result for more information about the different tool state results.
Additional Results
Percent Good:
This result returns the percentage of the data values that lie within the defined value range between "Lower Bound" and "Upper Bound" and therefore are classified as good.
Percent Bad:
This result returns the percentage of the data values that lie outside of the defined value range between "Lower Bound" and "Upper Bound" and therefore are classified as bad.
Processed Buffer Data:
This result returns all processed data passed in "Data Value" according to the settings defined for "Smoothing" and "Sample Limit". The data are returned in form of a tuple.
Current Buffer Length:
This result returns the current length of the buffered data that have been processed so far. It corresponds to the number of data values returned in "Buffer Data".
Processing Time:
This result returns the duration of the most recent execution of the tool in milliseconds. The result is provided as additional result. Therefore, it is hidden by default but it can be displayed via the 
button beside the tool results. For more information see the section Processing Time in the tool reference overview.
Application Examples
This tool is used in the following MERLIC Vision App examples:
- check_saw_angles.mvapp
