Description
Relative event sample/time offset when both supplied indices share the same origin, which cancels in subtraction; sample frequency is explicit and offsets may be negative.
Neurophysiological research records use sample coordinates, event clocks, epoch boundaries, references, signal amplitudes, and spectral bins. Timing conversions and support shares depend on rate, origin, exclusion, and boundary policies. Arithmetic on supplied values is separate from signal detection, validated acquisition, or neurological interpretation.
Relative event sample/time offset when both supplied indices share the same origin, which cancels in subtraction; sample frequency is explicit and offsets may be negative.
When to use this tool
Use EEG Event Sample Index Offset Term when you need this research signal, sample, event, epoch, reference, or spectral component from supplied data.
How to use the tool and how it works
- Enter eventSample, epochStartSample, sampleHz. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read relativeSample, relativeSeconds. Use the output convention below.
For positive sampleHz return relativeSample=eventSample-epochStartSample and relativeSeconds=relativeSample/sampleHz.1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| eventSample | Event Sample | Required. Safe integer. |
| epochStartSample | Epoch Start Sample | Required. Safe integer. |
| sampleHz | Positive samples per second. | Required. Finite number; strictly above 0. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| relativeSample | Relative Sample | Required. Safe integer. |
| relativeSeconds | Relative Seconds | Required. Finite number. |
{
"input": {
"eventSample": 1500,
"epochStartSample": 1000,
"sampleHz": 500
},
"output": {
"relativeSample": 500,
"relativeSeconds": 1
}
}Limitations and assumptions
- Both indices use one integer sample coordinate system and negative offsets are allowed. This does not choose an epoch convention, detect an event, verify the rate, or interpret a neurological response.
- 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
Use calibrated acquisition and the intended signal-analysis protocol for a complete assessment. Verify sample rate, coordinate origin, clock offsets, reference configuration, filtering assumptions, and observation support.
References
Similar or alternative tools
- EEG Sample Event Offset
Map one supplied EEG event sample relative to an explicit sample origin/rate and sample-rounding convention.
- EEG Annotation Recording Start Offset
Explicit clock-offset corrected annotation index with nearest-sample, half-toward-positive-infinity rounding.