and after Hanning smoothing. Useful for Zeeman enthusiasts.2deriv Take 2-sided derivative of spectrum before plotting. histo Plot the spectrum as a histogram instead of joining points. pstyle1 Alternative plot style, where the object and position
information is omitted and the comment field is centered at the top of the plot. Typically, this is used for publication-quality plots (the source name, if required. should be inserted into the comment field).pstyle2 Alternative plot style, where the object and position
information is omitted, the comment field is centered at the top of the plot (as with options=pstyle1), and the x and y axis labels are omitted. Typically, this is used to generate publication-quality n x m matrix plots (the source name, if required should be inserted into the comment field).posfit If width>1, a source position is estimated from a Gaussian
fit to the moment map. The moment map is formed using the velocity range specified by the profile parameter. If yaxis=point, this new position is used when forming the spectrum (the region set by the initial coord parameter and the width parameter is not changed).measure Measure various spectral parameters on plotted spectrum.
If a profile window is set, the line is only measured within this window. If the order keyword is used, the fit is always subtracted before spectral fitting. If a plot device is selected, the width-maximised 50% and 20% points are highlighted with a circle and the width-minimised points are highlighted with a cross. Zeroth moment (profile area), first moment (mean velocity/frequency/channel) and second moment (dispersion) are calculated in the usual way. These parameters are not robust unless careful use of the profile and clip parameters is made. However, more robust moment-like parameters are also calculated by using an algorithm which minimises the mean absolute deviation of the flux-weighted velocities