This function reads a binary .iqt file from the

Tektronix RSA3408A Real-Time Spectrum Analyzer and

performs amplitude and phase correction.

If filename is not specified or is empty,

the user is prompted for the filename.

A subset of the recording can be returned by specifying the first and

last element numbers indexed from 1.

If first is not specified or is empty, it defaults to 1.

If last is not specified or is empty, it defaults to the length of the

recording.

-　This function reads a binary .iqt file from the

　Tektronix RSA3408A Real-Time Spectrum Analyzer and

　performs amplitude and phase correction.

　If filename is not specified or is empty,

　the user is prompted for the filename.

　A subset of the recording can be returned by specifying the first and

　last element numbers indexed from 1.

　If first is not specified or is empty, it defaults to 1.

　If last is not specified or is empty, it defaults to the length of the

　recording.