deterministic#
- discovery.deterministic.makedelay_binary_phases(pulsarterm=True)[source]#
Factory for computing cphase and sphase vectors from binary parameters.
- discovery.deterministic.makedelay_binary_coefficients(pulsarterm=True)[source]#
Factory for computing coefficients to multiply phase vectors.
- discovery.deterministic.cos2comp(f, df, A, f0, phi, t0)[source]#
Project signal A * cos(2pi f t + phi) onto Fourier basis cos(2pi k t/T), sin(2pi k t/T) for t in [t0, t0+T].
- discovery.deterministic.chromatic_exponential(psr, fref=1400.0)[source]#
Factory function for chromatic exponential delay model.
Creates a delay function that models chromatic exponential events (e.g., profile state changes) with frequency-dependent amplitude scaling.
- Parameters:
- Returns:
delay – Function with signature (t0, log10_Amp, log10_tau, sign_param, alpha) -> ndarray Computes chromatic exponential delay:
\[\Delta(t) = \pm A_0 \exp\left(-\frac{t - t_0}{\tau}\right) \left(\frac{f_{\text{ref}}}{f}\right)^\alpha H(t - t_0)\]where \(H(t - t_0)\) is the Heaviside step function.
- Return type:
callable
- discovery.deterministic.chromatic_annual(psr, fref=1400.0)[source]#
Factory function for chromatic annual delay model.
Creates a delay function that models chromatic annual sinusoidal variations (e.g., annual DM or scattering variations) with frequency-dependent amplitude scaling.
- Parameters:
- Returns:
delay – Function with signature (log10_Amp, phase, alpha) -> ndarray Computes chromatic annual delay:
\[\Delta(t) = A_0 \sin(2\pi f_{\text{yr}} t + \phi) \left(\frac{f_{\text{ref}}}{f}\right)^\alpha\]where \(f_{\text{yr}}\) is the annual frequency (1/year).
- Return type:
callable
- discovery.deterministic.chromatic_gaussian(psr, fref=1400.0)[source]#
Factory function for chromatic Gaussian delay model.
Creates a delay function that models chromatic Gaussian events (e.g., transient DM variations, localized profile events) with frequency-dependent amplitude scaling.
- Parameters:
- Returns:
delay – Function with signature (t0, log10_Amp, log10_sigma, sign_param, alpha) -> ndarray Computes chromatic Gaussian delay:
\[\Delta(t) = \pm A_0 \exp\left(-\frac{(t - t_0)^2}{2\sigma^2}\right) \left(\frac{f_{\text{ref}}}{f}\right)^\alpha\]- Return type:
callable
- discovery.deterministic.orthometric_shapiro(psr, binphase)[source]#
Factory function for orthometric Shapiro delay model.
Creates a delay function that models Shapiro delay in binary pulsars using the orthometric parameterization from Freire & Wex (2010).
- Parameters:
psr (Pulsar) – Pulsar object containing toas attribute
binphase (array-like) – Binary orbital phase \(\Phi\) at each TOA (same shape as psr.toas)
- Returns:
delay – Function with signature (h3, stig) -> ndarray Computes orthometric Shapiro delay (Equation 29 in Freire & Wex 2010):
\[\Delta_s = -\frac{2 h_3}{\zeta^3} \log(1 + \zeta^2 - 2 \zeta \sin\Phi)\]- Return type:
callable
- Raises:
ValueError – If binphase shape does not match psr.toas shape
References
Freire, P. C. C., & Wex, N. (2010). The orthometric parametrization of the Shapiro delay and an improved test of general relativity with binary pulsars. MNRAS, 409(1), 199-212.