Description
Subtract a supplied reference signal from one EEG channel value.
Neurological signal records distinguish event markers, sampling rate, polarity, reference amplitude and physical units. A pre-trigger duration may not equal a whole sample count, so the rounding policy changes the represented interval. Scalar subtraction and timestamp arithmetic do not detect an event, validate a recording or establish a diagnosis.
Subtract a supplied reference signal from one EEG channel value.
When to use this tool
Use EEG Reference Scalar Subtraction when you already have channelValue, referenceValue and need to subtract a supplied reference signal from one EEG channel value.
How to use the tool and how it works
- Enter channelValue, referenceValue. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read referencedValue. Use the output convention below.
Return channelValue-referenceValue on one compatible amplitude basis.1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| channelValue | Channel Value | Required. Finite number. |
| referenceValue | Reference Value | Required. Finite number. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| referencedValue | Referenced Value | Required. Finite number. |
{
"input": {
"channelValue": 12,
"referenceValue": 4
},
"output": {
"referencedValue": 8
}
}Limitations and assumptions
- This is scalar subtraction, not a full montage, artifact correction, signal interpretation or diagnosis.
- Inputs must satisfy both the field types and the cross-field conditions above. Invalid input causes an error; a successful false flag or documented placeholder is a different result.
- Numeric calculations use binary floating point unless exact decimal-integer arithmetic is explicitly stated. No hidden measurement tolerance or decimal rounding is added; nonfinite or out-of-contract results are rejected. Numeric signed-zero results are exported as zero.
Alternative or Complementary methods
Review the original signal, acquisition settings and annotation method when interpreting a recording. Use actual timestamps for variable timing and the complete reference/montage definition for signal analysis; preserve the local unit and rounding conventions.
References
Similar or alternative tools
- EEG Channel Polarity Record
Apply a supplied polarity reversal to a recorded EEG amplitude.
- EEG Epoch Pre Trigger Samples
Convert a supplied EEG pre-trigger duration to a rounded sample count.