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Last modified: December 2009

URL: http://cxc-newtest.cfa.harvard.edu/ciao4.2/delete_col.sl.html
AHELP for CIAO 4.2

delete_col

Context: sl.crates

Synopsis

Delete a column from a crate.

Syntax

delete_col(crate, colid);

Description

  • crate - input crate
  • colid - column name or number, where the first column is numbered 0

The delete_col command removes the column from the crate. The print_col_names command ("ahelp print_col_names") lists all the columns in the file with the corresponding numbers.

The command returns a "1" if the column is successfully deleted. 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

slsh> cr = read_file("evt2.fits");
slsh> print(get_col_names(cr));
['CHANNEL' 'COUNTS' 'STAT_ERR' 'BACKGROUND' 'BIN_LO' 'BIN_HI']
slsh> delete_col(cr, "STAT_ERR");
1
slsh> col_exists(cr, "STAT_ERR");
0
slsh> write_file(cr, "nostat.fits");
1

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

slsh> cr = read_file("evt2.fits");
slsh> delete_col(cr, 4);
1
slsh> col_exists(cr, "BACKGROUND");
0
slsh> write_file(cr, "edit.fits");
1

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.

See Also

sl.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, print_col_names, read_arf, read_file, read_pha, read_rmf, set_colvals, write_arf, write_file, write_pha, write_rmf
sl.crates_contrib
make_table_crate, scale_image_crate, write_columns

Last modified: December 2009