### astAddColumn

Add a new column definition to a table

#### Description:

Adds the definition of a new column to the supplied table. Initially, the column is empty. Values may be added subsequently using the methods of the KeyMap class.

#### Synopsis

void astAddColumn( AstTable $\ast$this, const char $\ast$name, int type, int ndim, int $\ast$dims, const char $\ast$unit )

#### Parameters:

##### this
Pointer to the Table.
##### name
The column name. Trailing spaces are ignored (all other spaces are significant). The supplied string is converted to upper case.
##### type
The data type associated with the column. See " Applicability:" below.
##### ndim
The number of dimensions spanned by the values stored in a single cell of the column. Zero if the column holds scalar values.
##### dims
An array holding the the lengths of each of the axes spanned by the values stored in a single cell of the column. Ignored if the column holds scalara values.
##### unit
A string specifying the units of the column. Supply a blank string if the column is unitless.

#### Applicability

##### Table
Tables can hold columns with any of the following data types - AST__INTTYPE (for integer), AST__SINTTYPE (for short int), AST__BYTETYPE (for unsigned bytes - i.e. unsigned chars), AST__DOUBLETYPE (for double precision floating point), AST__FLOATTYPE (for single precision floating point), AST__STRINGTYPE (for character string), AST__OBJECTTYPE (for AST Object pointer), AST__POINTERTYPE (for arbitrary C pointer) or AST__UNDEFTYPE (for undefined values created by astMapPutU).
##### FitsTable
FitsTables can hold columns with any of the following data types - AST__INTTYPE (for integer), AST__SINTTYPE (for short int), AST__BYTETYPE (for unsigned bytes - i.e. unsigned chars), AST__DOUBLETYPE (for double precision floating point), AST__FLOATTYPE (for single precision floating point), AST__STRINGTYPE (for character string).

#### Notes:

• This function returns without action if a column already exists in the Table with the supplied name and properties. However an error is reported if any of the properties differ.