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Last modified: December 2012

URL: http://cxc.harvard.edu/ciao/delete_col.html
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AHELP for CIAO 4.5

delete_col

Context: crates

Synopsis

Delete a column from a crate.

Syntax

delete_col(crate, colname)
delete_col(crate, colnum)

Description

  • crate - input table crate
  • colname - column name (case insensitive)
  • colnum - column number, where the first column is numbered 0

The delete_col command removes the column from the crate.

The get_col_names() routine ("ahelp get_col_names") can be used to find the columns in a Crate.

The column is only deleted from the data in the crate; it's not removed from the input file. The write_file command ("ahelp write_file") can be used to save the modified crate to a file.

Example 1

>>> cr = read_file("evt2.fits")
>>> print(get_col_names(cr))
['CHANNEL' 'COUNTS' 'STAT_ERR' 'BACKGROUND' 'BIN_LO' 'BIN_HI']
>>> delete_col(cr, "STAT_ERR")
>>> col_exists(cr, "STAT_ERR")
False
>>> write_file(cr, "nostat.fits")

Delete the STAT_ERR column from the crate, then use the col_exists command to confirm it has been deleted. Write the crate to nostat.fits.

Example 2

>>> cr = read_file("evt2.fits")
>>> delete_col(cr, 4)
>>> col_exists(cr, "BACKGROUND")
False
>>> write_file(cr, "edit.fits")

Delete column number 4 - the BACKGROUND column in this file - from the crate, then write the crate to file edit.fits.

Bugs

See the bug pages on the CIAO website for an up-to-date listing of known bugs.

Refer to the CIAO bug pages for an up-to-date listing of known issues.

See Also

contrib
add_colvals, make_image_crate, make_table_crate, scale_image_crate, smooth_image_crate, write_arrays, write_columns
crates
add_col, add_key, add_piximg, col_exists, copy_colvals, delete_key, delete_piximg, get_col, get_col_names, get_colvals, get_number_cols, is_virtual, read_file, read_pha, read_rmf, set_colvals, write_file, write_pha, write_rmf

Last modified: December 2012
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