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| == Help on makemask task: ==
| | {{makemask}} |
| <pre>
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| Make a mask image from rectangular boxes
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| The mask image must be consistent with a particular visibility file and source
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| selection; hence the need to specify the imaging parameters and source
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| selection.
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| If the source image has already been made, then a mask image can be made by:
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| Load the image into the viewer
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| click on tools (top just left of center)
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| click on Region Manager
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| make rectangular and/or polygon areas as needed
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| save as region file
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| This region file can substitute as a mask in most application.
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| You can also use taskname='clean' with interactive = T to make a mask when the
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| dirty image is produced.
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| Keyword arguments:
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| cleanbox -- Cleaning region:
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| default: [] defaults to inner quarter of image
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| Two specification types:
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| Explicit pixel ranges
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| example: cleanbox=[[110,110,150,145],[180,70,190,80]]
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| cleans two regions defined by the pixel ranges
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| Filename with pixel values with ascii format:
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| <fieldid blc-x blc-y trc-x trc-y> on each line
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| ----------------------------------------------------------------
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| vis -- Name of input visibility file
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| default: none; example: vis='ngc5921.ms'
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| imagename -- Name of output mask image
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| default: none; example: imagename='ngc5921.mask'
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| mode -- Type of selection
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| default: 'mfs'; example: mode='channel';
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| Options: 'mfs', channel'
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| nchan -- Number of channels to select
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| default: -1 (all); example: nchan=45
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| start -- Start channel
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| default=0; example: start=5
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| width -- Channel width (value > 1 indicates channel averaging)
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| default=1; example: width=5
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| step -- Step in channel number
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| default=1; example: step=2
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| imsize -- Image size in spatial pixels (x,y)
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| default = [256,256]; example: imsize=[512,512]
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| cell -- Cell size in arcseconds (x,y)
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| default=[0,0] = none; example: cell=[0.5,0.5]
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| phasecenter -- direction measure or fieldid for the mosaic center
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| default: '' (imply field=0 as center); example: phasecenter=6
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| or phasecenter='J2000 19h30m00 -40d00m00'
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| stokes -- Stokes parameters to image
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| default='I'; example: stokes='IQUV';
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| Options: 'I','IV','IQU','IQUV'
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| field -- Select field using field id(s) or field name(s).
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| [run listobs to obtain the list id's or names]
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| default: ''=all fields
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| If field string is a non-negative integer, it is assumed a field index
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| otherwise, it is assumed a field name
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| field='0~2'; field ids 0,1,2
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| field='0,4,5~7'; field ids 0,4,5,6,7
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| field='3C286,3C295'; field named 3C286 adn 3C295
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| field = '3,4C*'; field id 3, all names starting with 4C
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| spw -- Select spectral window/channels
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| default: ''=all spectral windows and channels
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| spw='0~2,4'; spectral windows 0,1,2,4 (all channels)
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| spw='<2'; spectral windows less than 2 (i.e. 0,1)
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| spw='0:5~61'; spw 0, channels 5 to 61
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| spw='0,10,3:3~45'; spw 0,10 all channels, spw 3, channels 3 to 45.
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| spw='0~2:2~6'; spw 0,1,2 with channels 2 through 6 in each.
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| spw='0:0~10;15~60'; spectral window 0 with channels 0-10,15-60
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| spw='0:0~10,1:20~30,2:1;2;3'; spw 0, channels 0-10,
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| spw 1, channels 20-30, and spw 2, channels, 1,2 and 3
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| </pre>
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