Edits CCDPACK image extensions
associate position list(s)
erase extension items
add a transform structure
invert a transform structure.
The associate list facility allows the names of position lists to be added to image extensions, these lists are then accessed when the image names are given in response to an INLIST prompt (provided the application NDFNAMES parameter is TRUE). This option also allows a single position list to be associated with a range of images.
Erase extension items is a safe way of deleting primitives and structures from an image CCDPACK extension and removes the need to remember the exact object name and path.
Add transform allows arbitrary transform structures to be added. The transform may be generated from linear transform coefficients, copied from a existing transform structure or may be specified as an expression. Forward and inverse transformations are required.
Invert transform inverts the sense of the transformation.
LINEAR – Linear and preserves straight lines.
INDEPENDENT – Preserves the independence of the axes.
DIAGONAL – Preserves the axes themselves.
ISOTROPIC – Preserves angles and shapes.
POSITIVE_DET – A component of reflection is absent.
NEGATIVE_DET – A component of reflection is present.
CONSTANT_DET – The scale factor is constant.
UNIT_DET – Areas (or volumes etc.) are preserved.
See SUN/61 Appendix B for more details of transformation classification and a table of the classifications of common mappings.
"
EXPRES"
is
chosen then this parameter decides whether or not a classification of the transformation using
parameters XFOR, YFOR, XINV and YINV will be given. Classification is optional, but you should
note that the information can be used to make other applications run more efficiently, and the lack of a
classification may stop certain types of operation. See SUN/61 appendix B for details. Linear
transformations are classified by this routine using the FITTYPE parameter. [FALSE] "
sub-expressions"
used in the
expressions XFOR, YFOR, XINV and YINV. These parameters should be used when repeated
expressions are present in complex transformations. Sub-expressions may contain references
to other sub-expressions and constants (PA-PZ). An example of using sub-expressions
is:
XFOR $>$
’
XX=PA$\ast $ASIND(FA/PA)$\ast $X/FA’
YFOR $>$
’
YY=PA$\ast $ASIND(FA/PA)$\ast $Y/FA’
XINV $>$
’
X=PA$\ast $SIND(FB/PA)$\ast $XX/FB’
YINV $>$
’
Y=PA$\ast $SIND(FB/PA)$\ast $YY/FB’
FA $>$
SQRT(X$\ast $X$+$Y$\ast $Y)
PA $>$
100D0
FB $>$
SQRT(XX$\ast $XX$+$YY$\ast $YY)
FITTYPE = _INTEGER (Read)
1 – shift of origin
2 – shift of origin and rotation
3 – shift of origin and magnification
4 – shift of origin, rotation and magnification (solid body)
5 – a full six parameter fit
The value of this parameter is used to classify the transformation (see the CLASS parameter). [5]
"
ALIST"
). If a single name is given then this position list will be associated with all the input
images. If a list of names is given then there should be as many names as input images.
The order of the input image names is shown so that the correct correspondence may be
achieved.
Position list names may NOT include wildcards. So a comma separated list of explicit names should
be used and/or the names should be read from indirection files (the indirection indicator is
"
$$"
).
If the logging system has been initialised using CCDSETUP then the value specified there will be
used. Otherwise, the default is "
CCDPACK.LOG"
. [CCDPACK.LOG]
TERMINAL – Send output to the terminal only
LOGFILE – Send output to the logfile only (see the LOGFILE parameter)
BOTH – Send output to both the terminal and the logfile
NEITHER – Produce no output at all
If the logging system has been initialised using CCDSETUP then the value specified there will be
used. Otherwise, the default is "
BOTH"
. [BOTH]
ALIST
ERASE
TRANSFORM
INVERT
The "
ALIST"
option "
associates"
a position list(s) with images (this sets the "
CURRENT_LIST"
item).
This is useful when importing position lists generated externally to CCDPACK.
The "
ERASE"
option removes a named item from image extensions. Two possible items are
"
CURRENT_LIST"
and "
TRANSFORM"
.
The "
TRANSFORM"
option allows the generation or import of transforms into image extensions.
Transforms from other images may be copied. Linear transforms may be generated from the (6)
coefficients. General transforms may be specified by algebraic-like expressions containing the
functions allowed by the TRANSFORM package (SUN/61). If you intend to do this, see the related
parameters (XFOR, YFOR, XINV, YINV, FA-FZ, PA-PZ, CLASSIFY and CLASS) and the examples
section.
The "
INVERT"
option inverts the sense of transformations in the images. [ALIST]
"
ERASE"
is chosen then the value of this parameter names the
CCDPACK extension item of the input images which is to be erased. Typical items are
"
CURRENT_LIST"
, "
TRANSFORM"
and "
SET"
. If "
SET"
is used, then the FIXWCS parameter will be
used to decide whether to remove any CCD_SET-domain frames from the WCS component. XFOR $>$
’
XX=SQRT(FX$\ast $FX$+$FY$\ast $FY)’
YFOR $>$
’
YY=ATAN2D(-FY,FX)’
XINV $>$
’
X=XX$\ast $SIND(YY)$+$PA’
YINV $>$
’
Y=-YY$\ast $COSD(XX)$+$PB’
FX $>$
X-PA
FY $>$
Y-PB
PA $>$
X-centre-value
PB $>$
Y-centre-value
This maps (X,Y) to (R,THETA) about a specified centre.
"
STRUCT"
is chosen then this parameter is used to access the HDS object which contains a
transform structure to copy into the input images. The standard place to store a transform structure (in
CCDPACK NDFs) is
NDF_NAME.MORE.CCDPACK.TRANSFORM
"
COEFF"
is chosen then the values of this parameter are the 6 coefficients of a linear transformation of the
type:
X’ = PA $+$
PB$\ast $X
$+$
PC$\ast $Y
Y’ = PD $+$
PE$\ast $X
$+$
PF$\ast $Y
The default is the identity transformation.
[0,1,0,0,0,1] [PA,PB,PC,PD,PE,PF]
"
TRANSFORM"
is
selected then this parameter specifies the type of transform which will be supplied. Valid returns are
COEFF
EXPRES
STRUCT
If "
COEFF"
is chosen then the transform will be generated from the 6 coefficients of the
equations:
X’ = PA $+$
PB$\ast $X
$+$
PC$\ast $Y
Y’ = PD $+$
PE$\ast $X
$+$
PF$\ast $Y
supplied in the order PA,PB,PC,PD,PE,PF.
If "
STRUCT"
is chosen then an existing transformation structure will be copied into the extensions of
the images. Note that no checking of the transforms validity will be made.
If "
EXPRES"
is chosen then the transformation will be specified using algebraic-like statements of the
type:
XFOR $>$
’
XX=PA$+$PC$\ast $X’
YFOR $>$
’
YY=PD$+$PE$\ast $Y’
XINV $>$
’
X=(XX-PA)/PC’
YINV $>$
’
Y=(YY-PD)/PE’
The values of PA-PZ are accessed through the PA-PZ parameters. The PA-PZ’s are reserved for constants (FA-FZ are also reserved for repeated expressions). This example allows independent offsets and scales in X and Y. The inverse transformation must be supplied. [COEFF]
"
EXPRES"
is chosen then this parameter’s value is the transformation that
maps to the new X coordinate. The expression can contain constants, arithmetic operators
($+$,-,/,$\ast $,$\ast $$\ast $)
and the functions described in SUN/61 (SIN,COS,TAN, etc.).
Constants may be specified using the special tokens PA-PZ. Prompts for the values for these tokens will then be made (this provides a mechanism for parameterising functions allowing trivial value changes). Sub-expressions which occur in many places may also be specified using the special tokens FA-FZ. These are prompted for and placed into the main expression. Sub-expressions may contain references to constants and other sub-expressions. An example expression is:
XFOR $>$
’
XX=PA$\ast $ASIND(FA/PA)$\ast $X/FA’
Note the single quotes. They are necessary to protect the equals sign.
"
EXPRES"
is chosen then this parameter’s value is the transformation that maps to the old X
coordinate - the inverse transformation of XFOR. The expression can contain constants, arithmetic operators
($+$,-,/,$\ast $,$\ast $$\ast $)
and the functions described in SUN/61 (SIN,COS,TAN, etc.).
Constants may be specified using the special tokens PA-PZ prompts for values for these tokens will then be made (this provides a mechanism for parameterising functions allowing trivial values changes). Sub-expressions which occur in many places may also be specified using the special tokens FA-FZ. These are prompted for and placed into the main expression. Sub-expressions may contain references to constants and other sub-expressions. An example expression is:
XINV $>$
’
X=PA$\ast $SIND(FB/PA)$\ast $XX/FB’
Note the single quotes. They are necessary to protect the equals sign.
"
EXPRES"
is chosen then this parameter’s value is the transformation that
maps to the new Y coordinate. The expression can contain constants, arithmetic operators
($+$,-,/,$\ast $,$\ast $$\ast $)
and the functions described in SUN/61 (SIN,COS,TAN, etc.).
Constants may be specified using the special tokens PA-PZ. Prompts for the values of these tokens will then be made (this provides a mechanism for parameterising functions allowing trivial value changes). Sub-expressions which occur in many places may also be specified using the special tokens FA-FZ. These are prompted for and placed into the main expression. Sub-expressions may contain references to constants and other sub-expressions. An example expression is:
YFOR $>$
’
YY=PA$\ast $ASIND(FA/PA)$\ast $Y/FA’
Note the single quotes. They are necessary to protect the equals sign.
"
EXPRES"
is chosen then this parameter’s value is the transformation that maps to the old Y
coordinate - the inverse transformation of YFOR. The expression can contain constants, arithmetic operators
($+$,-,/,$\ast $,$\ast $$\ast $)
and the functions described in SUN/61 (SIN,COS,TAN, etc.).
Constants may be specified using the special tokens PA-PZ. Prompts for the values of these tokens will then be made (this provides a mechanism for parameterising functions allowing trivial value changes). Sub-expressions which occur in many places may also be specified using the special tokens FA-FZ. These are prompted for and placed into the main expression. Sub-expressions may contain references to constants and other sub-expressions. An example expression is:
YINV $>$
’
Y=PA$\ast $SIND(FB/PA)$\ast $YY/FB’
Note the single quotes. They are necessary to protect the equals sign.
’
$\ast $’
inlist=reference_set "
associate"
a single position list called reference_set
with all the images in the current directory. ’
"
image1,image2,image3"
’
’
"
pos1.dat,pos2.dat,pos3.dat"
’
"
*"
’
$\ast $’
’
[10.25,1,0,-101.1,0,1]’
fittype=1 ’
[0,0.965926,-0.258819,0,0.258819,0.965926]’
fittype=2 ’
"
xx=x$\ast $cosd(y)"
’
yfor=’
"
yy=y"
’
xinv=’
"
x=xx/cosd(yy)"
’
yinv=’
"
y=yy"
’
’
"
x=xx"
’
yfor=’
"
y=180/pi$\ast $log(tand((90d0$+$min(pa,max(-pa,yy))/2d0)))"
’
xinv=’
"
xx=x"
’
yinv=’
"
2d0$\ast $(atand(exp(y$\ast $pi/180d0)))-90d0"
’
NDF extension items. All NDF extension items dealt with by this routine are in the structure .MORE.CCDPACK.
When using the MODE=ALIST option the item CURRENT_LIST in the CCDPACK extension of the input images is set to the name of the input list(s). Such image items may be used by other CCDPACK position list processing routines to automatically access these lists.
When using the MODE=ERASE option the name of the item to be erase is the name of the structure or primitive after the XXX.MORE.CCDPACK has been removed.
Transforms are stored in the item .MORE.CCDPACK.TRANSFORM .
If MODE=ERASE, NAME=SET and FIXWCS=TRUE, the WCS component of the NDF may also be modified.
"
current"
value is
the value assigned on the last run of the application. If the application has not been run then the
"
intrinsic"
defaults, as shown in the parameter help, apply.
Retaining parameter values has the advantage of allowing you to define the default behaviour of the application but does mean that additional care needs to be taken when using the application after a break of sometime. The intrinsic default behaviour of the application may be restored by using the RESET keyword on the command line.
Certain parameters (LOGTO and LOGFILE) have global values. These global values will always take precedence, except when an assignment is made on the command line. Global values may be set and reset using the CCDSETUP and CCDCLEAR commands.