NAME

sections -- expand an image template

USAGE

sections images

PARAMETERS

images

Image template or list of images. There is no check that the names are images and any name may be used. The thing which distinguishes an image template from a file template is that the special characters [ and ] are interpreted as image sections rather than a character class wildcard unless preceded by the escape character !. To explictly limit a wildcard template to images one should use an appropriate extension such as ".imh".

option = "fullname"

The options are:

"nolist"

Do not print list.

"fullname"

Print the full image name for each image in the template.

"root"

Print the root name for each image in the template.

"section"

Print the section for each image in the template.

nimages

The number of images in the image template.

DESCRIPTION

The image template list images is expanded and the images are printed one per line on the standard output unless the "nolist" option is given. Other options allow selection of a portion of the image name. The number of images in the list is determined and stored in the parameter nimages .

This task is used for several purposes:

(1)

To verify that an image template is expanded as the user desires.

(2)

To create a file of image names which include image sections.

(3)

To create a file of new image names using the concatention feature of the image templates.

(4)

To determine the number of images specified by the user in a command language script.

There is no check that the names are images and any name may be used. The thing which distinguishes an image template from a file template is that the special characters [ and ] are interpreted as image sections rather than a character class wildcard unless preceded by the escape character !. To explictly limit a wildcard template to images one should use an appropriate extension such as ".imh".

EXAMPLES

1. Calculate and print the number of images in a template:

	cl> sections fits*.imh opti=no
	cl> = sections.nimages
	cl> 7

2. Expand an image template:

	cl> sections fits*![3-9].imh[1:10,*]
	fits003.imh[1:10,*]
	fits004.imh[1:10,*]
	<etc.>

Note the use of the character class escape, image section appending, and explicit use of the .imh extension.

3. Create a new list of image names by adding the suffix "new":

	cl> sections jan18???//new
	jan18001new
	jan18002new
	<etc.>

Note the use of the append syntax. Also there is no guarantee that the files are actually images.

4. Subtract two sets of images:

	cl> sections objs*.imh[100:200,300:400] > objslist
	cl> sections skys*.imh[100:200,300:400] > skyslist
	cl> sections %objs%bck%* > bcklist
	cl> imarith @objslist - @skyslist @bcklist

Note the use of the substitution syntax.

TIME REQUIREMENTS

BUGS

The image list is not sorted.

SEE ALSO

files