### astSetFits$<$X$>$

Store a keyword value in a FitsChan

#### Description:

This is a family of functions which store values for named keywords within a FitsChan at the current card position. The supplied keyword value can either over-write an existing keyword value, or can be inserted as a new header card into the FitsChan.

The keyword data type is selected by replacing $<$X$>$ in the function name by one of the following strings representing the recognised FITS data

types:

• CF - Complex floating point values.

• CI - Complex integer values.

• F - Floating point values.

• I - Integer values.

• L - Logical (i.e. boolean) values.

• S - String values.

• CN - A " CONTINUE" value, these are treated like string values, but are encoded without an equals sign.

The data type of the " value" parameter depends on $<$X$>$ as follows:

• CF - " double $\ast$" (a pointer to a 2 element array holding the real and imaginary parts of the complex value).

• CI - " int $\ast$" (a pointer to a 2 element array holding the real and imaginary parts of the complex value).

• F - " double" .

• I - " int" .

• L - " int" .

• S - " const char $\ast$" .

• CN - " const char $\ast$" .

#### Synopsis

void astSetFits$<$X$>$( AstFitsChan $\ast$this, const char $\ast$name, $<$X$>$type value, const char $\ast$comment, int overwrite )

#### Parameters:

##### this
Pointer to the FitsChan.
##### name
Pointer to a null-terminated character string containing the FITS keyword name. This may be a complete FITS header card, in which case the keyword to use is extracted from it. No more than 80 characters are read from this string.
##### value
The keyword value to store with the named keyword. The data type of this parameter depends on $<$X$>$ as described above.
##### comment
A pointer to a null terminated string holding a comment to associated with the keyword. If a NULL pointer or a blank string is supplied, then any comment included in the string supplied for the " name" parameter is used instead. If " name" contains no comment, then any existing comment in the card being over-written is retained. Otherwise, no comment is stored with the card.
##### overwrite
If non-zero, the new card formed from the supplied keyword name, value and comment string over-writes the current card, and the current card is incremented to refer to the next card (see the " Card" attribute). If zero, the new card is inserted in front of the current card and the current card is left unchanged. In either case, if the current card on entry points to the " end-of-file" , the new card is appended to the end of the list.

#### Notes:

• The function astSetFitsU can be used to indicate that no value is associated with a keyword.

• The function astSetFitsCM can be used to store a pure comment card (i.e. a card with a blank keyword).

• To assign a new value for an existing keyword within a FitsChan, first find the card describing the keyword using astFindFits, and then use one of the astSetFits$<$X$>$ family to over-write the old value.

• If, on exit, there are no cards following the card written by this function, then the current card is left pointing at the " end-of-file" .

• An error will be reported if the keyword name does not conform to FITS requirements.