Doppler velocity
function fisspy.analysis.doppler.lambdameter(wv, data0, hw=0.05, iwc=None, wvRange=None, cubic=False, rfm='hm', alpha=None, reguess=True, pf=False, corInstShift=False, refSpec=None)
Description: Determine the lambdameter chord center for a given half width or intensity.Parameters
- wv (numpy.ndarray) - A Calibrated wavelength.
- data (numpy.ndarray) - n (n=2 or n=3) dimensional spectral profile data. The last dimension should be the spectral component, and the size is equal to that of wv.
- hw (float, optional) - A half width of the horizontal line segment.
- wvRange (list, optional) - Wavelength range to apply the lambdameter.
- iwc (float, optional) - Initial guess of the center of the lambdameter. Default is the minimum of the given at each line profile.
- cubic (bool, optional) - If True, using cubic interpolation to determine the function of the profile. If False, using linear interpolation. Default is False.
- rfm (str, optional) - Root-finding method. Options-'ori': bisector method, 'cm': Chae's method, 'nrm': Newton-Raphson method, 'hm': Halley's method.
- alpha (bool, optional) - Stepsize of the root-finding. We recommand you does not touch this value except for using chae's method.
- reguess (bool, optional) - Reguess the initial guess and repeat the calculation for the failed position to derive the line center by changing the intial guess automatically.
- pr (bool, optional) - Print the result. Defualt is False.
- corInstShift (bool, optional) - If True, correct the instrument shift. Default is False. Note, this process can also be done outside this function.
- refSpec (float, optional) - Reference spectrum for the correction of the instrument shift. If corInstShift is True, this should be given.
Returns
- wc (numpy.ndarray) - n-dimensional array of central wavelength values.
- intc (numpy.ndarray) - n-dimensional array of intensities of the line segment.