Description
Explicit supplied filter group-delay shift, preserving fractional sample positions rather than silently rounding event timing.
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.
Explicit supplied filter group-delay shift, preserving fractional sample positions rather than silently rounding event timing.
When to use this tool
Use EEG Filter Delay Sample Shift 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 sampleIndex, delaySamples, sampleHz, compensate. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read shiftedIndex, timeShiftSeconds. Use the output convention below.
For nonnegative integer sampleIndex and positive sampleHz return shiftedIndex=sampleIndex-delaySamples if compensate, otherwise sampleIndex+delaySamples. Return timeShiftSeconds with the same signed delay divided by sampleHz.1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| sampleIndex | Sample Index | Required. Safe integer; minimum 0. |
| delaySamples | Finite supplied delay, possibly fractional; no rounding is applied. | Required. Finite number. |
| sampleHz | Positive samples per second. | Required. Finite number; strictly above 0. |
| compensate | Compensate | Required. Boolean. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| shiftedIndex | Shifted Index | Required. Finite number. |
| timeShiftSeconds | Time Shift Seconds | Required. Finite number. |
{
"input": {
"sampleIndex": 1000,
"delaySamples": 25,
"sampleHz": 500,
"compensate": true
},
"output": {
"shiftedIndex": 975,
"timeShiftSeconds": -0.05
}
}Limitations and assumptions
- DelaySamples may be fractional and is supplied rather than estimated from filter coefficients, frequency response, or data. Shifted indices may be negative or fractional; no actual signal is moved, recording aligned, or clinical event timing verified.
- 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
- Nerve Trace Trigger Offset Token
Compute signed trace timing relative to a supplied trigger and offset, without a nerve-conduction interpretation.
- EEG Annotation Recording Start Offset
Explicit clock-offset corrected annotation index with nearest-sample, half-toward-positive-infinity rounding.