Time Base

Shipping

time_base

Time-ramp source: value at each sample equals its timestamp

Signature

Outputs

timeSignal

Parameters

Key	Type	Default
`start_time`	float	0.0s
`duration`	float	1.0s
`sample_rate`	float	1000.0Hz

Description

Time Base is a pure source node that emits a time-ramp signal: the value of each sample is equal to its own timestamp. It produces a uniformly sampled Signal on the time output whose values run from start_time to start_time + duration, and whose sample spacing is $Δ t = 1/ sample_rate$ . It has no inputs.

The three parameters fully determine the output. sample_rate (in Hz) sets the number of samples per second, duration (in s) sets the total span, and start_time (in s) offsets the origin. The signal length is $N = ⌊ duration \cdot sample_rate ⌋$ , and sample $i$ has value and timestamp $t_{i} = start_time + i / sample_rate$ .

Unit-wise the output carries the physical unit seconds on both its values and its timestamp axis; downstream nodes that multiply or divide against it therefore compose units correctly (e.g. a slope in V/s times time yields V). The ramp is exact and noiseless, so its uncertainty (sigma) is zero — it introduces no measurement error into a pipeline.

Time Base is stateless: every evaluation regenerates the full ramp deterministically from its parameters, with no dependence on prior graph ticks.

Mathematics

t_{i} = start_time + \frac{i}{sample_rate}, i = 0, 1, \dots, N - 1

N = ⌊ duration \cdot sample_rate ⌋

y_{i} = t_{i}, Δ t = \frac{1}{sample_rate}

Examples

A one-second ramp at 1 kHz

With start_time = 0, duration = 1.0, sample_rate = 1000, the node emits $N = 1000$ samples with values $0, 0.001, 0.002, \dots, 0.999$ s. Feeding this into a trigonometry or signal_generator stage lets you synthesize any explicit function of time.

time_base(start=0, dur=1, fs=1000) -> [0.000, 0.001, ..., 0.999] s

Driving an analytic waveform via formula

Wire time into a formula node evaluating sin(2*pi*50*t) to build a 50 Hz sine from first principles, guaranteeing the phase reference matches the exact sample timestamps rather than an implicit index. The unit of t being s makes $2 π f t$ dimensionless as required.

Applications

Providing an explicit independent variable $t$ for symbolic/analytic signal synthesis in **formula** and **trigonometry** pipelines.
Generating a controlled time axis for parametric sweeps, chirps, and envelope schedules where the ramp is scaled or offset before use.
Building test and reference signals with an exact, unit-tagged time base for verifying filter, resampling, or integration nodes.
Serving as the horizontal axis reference when plotting or exporting synthesized data at a known, reproducible sample rate.

Neat

The output is the rare signal where values and timestamps are identical, so passing it through **derivative** yields a constant $1$ (dimensionless s/s) and through **integral** yields $t^2/2$ — a built-in check of those operators.

Because the ramp is analytically exact, it carries zero sigma: it is a noiseless reference against which uncertainty-propagating nodes downstream can be isolated and audited.

Known issues

Sample count uses a floor of $\text{duration} \cdot \text{sample\_rate}$; non-integer products (e.g. duration 0.15 s at 1000 Hz) drop the fractional sample, so the emitted signal may end just short of `start_time + duration`.

`duration` is clamped at a minimum of 0.001 s and `sample_rate` at 1.0 Hz; requesting smaller values is coerced to these bounds rather than producing an empty or sub-sample signal.