funregions(7) | SAORD Documentation | funregions(7) |

foo.fits[circle(512,512,100)]It is also possible to put region specification inside a file and then pass the filename in bracket notation:

foo.fits[@my.reg]When region filters are passed in bracket notation in this manner, the filtering is set up automatically when the file is opened and all processing occurs through the filter. Programs also can use the filter library API to open filters explicitly.

# comment until end of line global keyword=value keyword=value ... # set global value(s) # include the following file in the region descriptor @file # use the FITS image as a mask (cannot be used with other regions) @fitsimage # each region expression contains shapes separated by operators [region_expression1], [region_expression2], ... [region_expression], [region_expression], ...A single region expression consists of:

# parens and commas are optional, as is the + sign [+-]shape(num , num , ...) OP1 shape num num num OP2 shape ...e.g.:

([+-]shape(num , num , ...) && shape num num ⎪⎪ shape(num, num) # a comment can come after a region -- reserved for local properties [+-]shape(num , num , ...) # local properties go here, e.g. color=redThus, a region descriptor consists of one or more region expressions or

shape: arguments: ----- ---------------------------------------- ANNULUS xcenter ycenter inner_radius outer_radius BOX xcenter ycenter xwidth yheight (angle) CIRCLE xcenter ycenter radius ELLIPSE xcenter ycenter xwidth yheight (angle) FIELD none LINE x1 y1 x2 y2 PIE xcenter ycenter angle1 angle2 POINT x1 y1 POLYGON x1 y1 x2 y2 ... xn ynIn addition, the following regions accept

shape arguments ----- ------------------------------------------ ANNULUS xcenter ycenter radius1 radius2 ... radiusn ANNULUS xcenter ycenter inner_radius outer_radius n=[number] BOX xcenter ycenter xw1 yh1 xw2 yh2 ... xwn yhn (angle) BOX xcenter ycenter xwlo yhlo xwhi yhhi n=[number] (angle) CIRCLE xcenter ycenter r1 r2 ... rn # same as annulus CIRCLE xcenter ycenter rinner router n=[number] # same as annulus ELLIPSE xcenter ycenter xw1 yh1 xw2 yh2 ... xwn yhn (angle) ELLIPSE xcenter ycenter xwlo yhlo xwhi yhhi n=[number] (angle) PIE xcenter ycenter angle1 angle2 (angle3) (angle4) (angle5) ... PIE xcenter ycenter angle1 angle2 (n=[number]) POINT x1 y1 x2 y2 ... xn ynNote that the circle accelerators are simply aliases for the annulus accelerators. See region geometry for more information about accelerators. Finally, the following are combinations of pie with different shapes (called "panda" for "Pie AND Annulus") allow for easy specification of radial sections:

shape: arguments: ----- --------- PANDA xcen ycen ang1 ang2 nang irad orad nrad # circular CPANDA xcen ycen ang1 ang2 nang irad orad nrad # circular BPANDA xcen ycen ang1 ang2 nang xwlo yhlo xwhi yhhi nrad (ang) # box EPANDA xcen ycen ang1 ang2 nang xwlo yhlo xwhi yhhi nrad (ang) # ellipseThe panda and cpanda specify combinations of annulus and circle with pie, respectively and give identical results. The bpanda combines box and pie, while epanda combines ellipse and pie. See region geometry for more information about pandas. The following "shapes" are ignored by funtools (generated by ds9):

shape: arguments: ----- --------- PROJECTION x1 y1 x2 y2 width # NB: ignored by funtools RULER x1 y1 x2 y2 # NB: ignored by funtools TEXT x y # NB: ignored by funtools GRID # NB: ignored by funtools TILE # NB: ignored by funtools COMPASS # NB: ignored by funtoolsAll arguments to regions are real values; integer values are automatically converted to real where necessary. All angles are in degrees and run from the positive image x-axis to the positive image y-axis. If a rotation angle is part of the associated WCS header, that angle is added implicitly as well. Note that 3-letter abbreviations are supported for all shapes, so that you can specify "circle" or "cir".

(col1,col2)=region(...)e.g.:

(X,Y)=annulus(x,y,ri,ro) (PHA,PI)=circle(x,y,r) (DX,DY)=ellipse(x,y,a,b[,angle])

Symbol Operation Use -------- --------- ----------------------------------- ! not Exclude this shape from this region & or && and Include only the overlap of these shapes ⎪ or ⎪⎪ inclusive or Include all of both shapes ^ exclusive or Include both shapes except their overlapNote that the !region syntax must be combined with another region in order that we be able to assign a region id properly. That is,

!circle(512,512,10)is not a legal region because there is no valid region id to work with. To get the full field without a circle, combine the above with

field() && !circle(512,512,10)

foo.fits[circle(512,512,10)⎪⎪circle(400,400,20)]On the other hand, the two shapes defined in the following example are given different region values:

foo.fits[circle(512,512,10),circle(400,400,20)]Of course these two examples will both mask the same table rows or pixels. However, in programs that distinguish region id's (such as funcnts ), they will act differently. The explicit OR operator will result in one region expression consisting of two shapes having the same region id and funcnts will report a single region. The comma operator will cause funcnts to report two region expressions, each with one shape, in its output. In general, commas are used to separate region expressions entered in bracket notation on the command line:

# regions are added to the filename in bracket notation foo.fits[circle(512,512,100),circle(400,400,20)]New-lines are used to separate region expressions in a file:

# regions usually are separated by new-lines in a file # use @filename to include this file on the command line circle(512,512,100) circle(400,400,20)Semi-colons are provided for backward compatibility with the original IRAF/PROS implementation and can be used in either case. If a pixel is covered by two different regions expressions, it is given the mask value of the

operator arguments: -------- ----------- - Globally exclude the region expression following '-' sign from ALL regions specified in this fileThe global exclude region can be used by itself; in such a case,

foo.fits[circle(512,512,10),@foo]A filter include file simply includes text without changing the state of the filter. It therefore can be used in expression. That is, if the file foo1 contains "pi==1" and foo2 contains "pha==2" then the following expressions are equivalent:

"[@foo1&&@foo2]" is equivalent to "[pi==1&&pha==2]" "[pha==1⎪⎪@foo2]" is equivalent to "[pi==1⎪⎪pha==2]" "[@foo1,@foo2]" is equivalent to "[pi==1,pha==2]"Be careful that you specify evaluation order properly using parenthesis, especially if the include file contains multiple filter statements. For example, consider a file containing two regions such as:

circle 512 512 10 circle 520 520 10If you want to include only events (or pixels) that are in these regions and have a pi value of 4, then the correct syntax is:

pi==4&&(@foo)since this is equivalent to:

pi==4 && (circle 512 512 10 ⎪⎪ circle 520 520 10)If you leave out the parenthesis, you are filtering this statement:

pi==4 && circle 512 512 10 ⎪⎪ circle 520 520 10)which is equivalent to:

(pi==4 && circle 512 512 10) ⎪⎪ circle 520 520 10)The latter syntax only applies the pi test to the first region. For image-style filtering, the

global color=red circle(10,10,2) circle(20,20,3) # color=blue circle(30,30,4)The first and third circles will be red, which the second circle will be blue. Note that funtools currently ignores region properties, as they are used in display only.

name description ---- ------------------------------------------ PHYSICAL pixel coords of original file using LTM/LTV IMAGE pixel coords of current file FK4, B1950 sky coordinate systems FK5, J2000 sky coordinate systems GALACTIC sky coordinate systems ECLIPTIC sky coordinate systems ICRS currently same as J2000 LINEAR linear wcs as defined in file AMPLIFIER mosaic coords of original file using ATM/ATV DETECTOR mosaic coords of original file using DTM/DTV

position arguments description ------------------ ------------------------------ [num] context-dependent (see below) [num]d degrees [num]r radians [num]p physical pixels [num]i image pixels [num]:[num]:[num] hms for 'odd' position arguments [num]:[num]:[num] dms for 'even' position arguments [num]h[num]m[num]s explicit hms [num]d[num]m[num]s explicit dms

size arguments description -------------- ----------- [num] context-dependent (see below) [num]" arc seconds [num]' arc minutes [num]d degrees [num]r radians [num]p physical pixels [num]i image pixelsWhen a "pure number" (i.e. one without a format directive such as 'd' for 'degrees') is specified, its interpretation depends on the context defined by the 'coordsys' keyword. In general, the rule is: All pure numbers have implied units corresponding to the current coordinate system. If no such system is explicitly specified, the default system is implicitly assumed to be PHYSICAL. In practice this means that for IMAGE and PHYSICAL systems, pure numbers are pixels. Otherwise, for all systems other than linear, pure numbers are degrees. For LINEAR systems, pure numbers are in the units of the linear system. This rule covers both positions and sizes. The input values to each shape can be specified in several coordinate systems including:

name description ---- ---------------------------- IMAGE pixel coords of current file LINEAR linear wcs as defined in file FK4, B1950 various sky coordinate systems FK5, J2000 GALACTIC ECLIPTIC ICRS PHYSICAL pixel coords of original file using LTM/LTV AMPLIFIER mosaic coords of original file using ATM/ATV DETECTOR mosaic coords of original file using DTM/DTVIf no coordinate system is specified, PHYSICAL is assumed. PHYSICAL or a World Coordinate System such as J2000 is preferred and most general. The coordinate system specifier should appear at the beginning of the region description, on a separate line (in a file), or followed by a new-line or semicolon; e.g.,

global coordsys physical circle 6500 9320 200The use of celestial input units automatically implies WORLD coordinates of the reference image. Thus, if the world coordinate system of the reference image is J2000, then

circle 10:10:0 20:22:0 3'is equivalent to:

circle 10:10:0 20:22:0 3' # j2000Note that by using units as described above, you may mix coordinate systems within a region specifier; e.g.,

circle 6500 9320 3' # physicalNote that, for regions which accept a rotation angle: ellipse (x, y, r1, r2, angle) box(x, y, w, h, angle) the angle is relative to the specified coordinate system. In particular, if the region is specified in WCS coordinates, the angle is related to the WCS system, not x/y image coordinate axis. For WCS systems with no rotation, this obviously is not an issue. However, some images do define an implicit rotation (e.g., by using a non-zero CROTA value in the WCS parameters) and for these images, the angle will be relative to the WCS axes. In such case, a region specification such as: fk4;ellipse(22:59:43.985, +58:45:26.92,320", 160", 30) will not, in general, be the same region specified as: physical;ellipse(465, 578, 40, 20, 30) even when positions and sizes match. The angle is relative to WCS axes in the first case, and relative to physical x,y axes in the second. More detailed descriptions are available for: Region Geometry, Region Algebra, Region Coordinates, and Region Boundaries.

April 14, 2011 | version 1.4.5 |