Plot Source List Positions

 

Source tables contain source positions in units of sky and/or image pixels. These positions can be displayed in the overlay channel of the image   with the command

 
DRAW/SOURCE_POSITIONS source_tab  [displ_flag] [symbol] [color]
                      [size_col] [text_col] [format]

 

• source_tab is the name of the source table. The table must contain positions in units of image pixels in columns with the labels :X_SKY and :Y_SKY, :X_IMA and :Y_IMA or :X_POS and :Y_POS. Such a table can be created from a table containing RA, DEC positions by the command TRANSFORM/RADEC. In case of a user-defined table with pixel coordinates measured from an image, the image y-coordinate must be flipped (NPIX(2) + 1 - y).
• displ_flag is a label display flag. If set to 1 the source sequence number, any other number or text retrieved from the column text_col will be displayed, if set to 0 no source sequence number, other number or text will be displayed. The default is displ_flag=1.
• symbol is the plot symbol (sqaure, cross or circle). In case of symbol=square a image pixels box is drawn centered at the source position. In case of symbol=circle a circle with a radius of 3 image pixels is drawn, and in case of symbol=cross a cross with a size of 7 image pixels is drawn in the default case. The size of the symbol (in units of image pixels) can also be retrieved from a table column, specified in the parameter size_col. The default symbol is symbol=square.
• color is the color of the symbol and label to be drawn. The allowed values are white, yellow, green, red, blue, cyan, magenta, backg and black. The default is color=white.
• size_col is the table column from which the size of the symbol (in units of image pixels) is read. (Only active for symbol=circle, the default is 7 image pixels). The column has to be specified as :LABEL.
• text_col is the table column from which the displayed text is read. (Only active for symbol=circle). The column has to be specified as :LABEL. The default is the sequence number.
• format is the text display format. Only for symbol=circle. Examples are F10.2, I6, E10.4, PE10.4, A20. The default is the I-format.

Examples:

DRAW/SOURCE\_POSITIONS  solst
DRAW/SOURCE\_POSITIONS  solst 0
DRAW/SOURCE\_POSITIONS  solst 1 circle yellow :RADIUS :CTS I6
DRAW/SOURCE\_POSITIONS  solst 1 circle yellow :RADIUS :NAME A20
DRAW/SOURCE\_POSITIONS  solst_2000 1 circle green ? :EXI_ML

In the third and fourth example a column :RADIUS must be created in the table solst.tbl specifying the radius of the circle in units of image pixels. In the fifth example a symbol with a default size of (radius of 3 image pixels) will be drawn. The value from column :EXI_ML will be displayed.