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: http://www.atnf.csiro.au/computing/software/miriad/doc/mbspect.html
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Task: mbspect Purpose: Make spectrum and measure velocities from a Miriad image. Categories: image analysis and display. MBSPECT makes a spectrum of the velocity or frequency axis of a Miriad image. The spectrum is integrated, averaged or beam- weighted, over the width specified, for the other image axes. Robust spectral baselines can be fitted, and the profile parameterised (velocities, widths, moments). The output spectrum can be plotted and/or written out as a miriad and/or ascii file for further analysis. Key: in The input image. vxy and xyv images are acceptable inputs. No default. Key: out The output spectrum, if required. Spectral units are always in the same units as the input file (even if a conversion is performed for the plot and/or log file). This spectrum can be read back into MbSpect. Key: coord The position, in world coordinates, for which the spectrum is required, e.g. coord=12:00:13,-42:00:43. The cube must have an RA and a DEC axis. The pixel with the nearest position is chosen. The default is the centre of the image (not necessarily the reference pixel). Key: width Two numbers, being the spatial width of the box in pixels (in RA and DEC) within which the spectrum is averaged (or integrated). Must be odd numbers. Default is 1,1. Key: xaxis The x-axis can be plotted as 'channel', 'frequency' ('FREQ'), 'radio' velocity ('VELO'), 'optical' velocity ('FELO'), or the units in the image. The default is whatever units are in the header. A second value will overwrite the default label for this axis. You can use pgplot escape characters to change fonts and sub/superscript level, e.g., 'Optical Velocity, \ficz\fr km\u-1s\d' will write 'cz' in italics and '-1' as a superscript. Key: yaxis If 'average' then the pixels enclosed in the x-y area specified are averaged. If 'sum' they are summed and normalized if the units are known. If 'point' they are optimally weighted according to the beam parameters, assuming that the source is unresolved. Default is 'average'. A second value will overwrite the default label for this axis. Key: xrange X-axis range for plot. The default is to self-scale to the region requested. The units are km/s for velocity and MHz for frequency (i.e. not the normal miriad convention). Key: yrange Y-axis range for plot. The default is to self-scale. Key: hann Hanning smoothing length (an odd integer < 15). The default is no smoothing (hann = 1). Key: order Order of optional robust (clipped polynomial) fit (0-10) to be applied to the spectral axis. If the order is positive (0 to 10), the fit is plotted on top of the data; if negative (-0 to -10), the fit is subtracted before plotting. The fit is always subtracted from any output data written. (For bulk removal of baselines in a cube, use contsub). Default is no fit. Key: options List of minimum match task enrichment options. 1deriv Take 1-sided derivative of spectrum before plotting 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 that minimises the mean absolute deviation of the flux- weighted velocities. minicube If an output file is selected (out parameter selected), a 3x3 mincube is produced. No extra spatial information is available; the extra spatial dimensions just duplicate spectral information in the central pixel. Useful for tasks such as regrid that only work with cubes whose dimensions are not unity. Key: clip Two values. Exclude pixels with values in the range clip(1) to clip(2). If only one value is given, then exclude -abs(clip) to abs(clip). Key: mask This specifies the x-axis ranges to be excluded from any continuum fit, e.g. those containing line emission. It consists of a number of pairs, each pair giving a start and end x-value. The default is that all channels are line-free, which is quite a good approximation if the line is weak compared to the continuum. The units of the x-axis values are the same as given by the xaxis keyword. Key: profile Two values. This specifies the x-axis range to be included for profile measurement (options=measure). It consists of a start and end x-value. The default is that all channels are used for profile measurement. For weak lines, you will normally need to set a profile window, a mask window a clip level, or any combination of the above. The profile and mask windows may be the same, although the profile window is limited to a single pair of values. The units of the x-axis values are the same as given by the xaxis keyword. Key: device Standard PGPLOT device. See the help on device for more information. Key: csize Up to 2 values. Character sizes in units of the PGPLOT default (which is ~ 1/40 of the view surface height) for the plot axis labels and the title. Defaults try to choose something sensible. Use 0.0 to default any particular value. Key: lines Up to 2 values. Line widths for the axes and the plot. Defaults to 1,1. Key: colors Up to 3 values. Colors for the main spectrum, the polynomial fit and the 'measure' parameters. Defaults to 1,2,3 Key: log Write spectrum to this ascii file. Spectral axis units are as specified by the xaxis keyword. Default is no output file. Key: comment A one-line comment which is written into the logfile and any plot. If the comment contains spaces you need to enclose it in single quotes. Note that this program does not report its version number so that gif and ps output can be piped. Revision: 1.23, 2015/05/12 00:05:35 UTC