Adds a scalar to an NDF data structure

#### Description:

The routine adds a scalar (i.e. constant) value to each pixel of an NDF’s  data array to produce a new NDF data structure.

#### Parameters:

Input NDF data structure, to which the value is to be added.
##### OUT = NDF (Write)
Output NDF data structure.
The value to be added to the NDF’s data array.
The title for the output NDF. A null value will cause the title of the NDF supplied for Parameter IN to be used instead. [!]

#### Examples:

This adds 17.3 to the NDF called a, to make the NDF called b. NDF b has the title "HD123456".