aptkernel

Computes the dipolar interaction kernel and components required for the approximate Pake transformation (APT).

Warning

This is a legacy function. Its use is not recommended for routine or accurate data analysis.

Syntax

K = aptkernel(t)
K = aptkernel(t,'Property',Value)
Parameters
  • t - Time axis (N-element array)
Returns
  • K - APT kernel elements (struct)

Description

K = aptkernel(t)

Generates a structure a APT kernel structure K containing the following fields:

  • .Base - Time/Frequency dipolar kernel ((N/2-2)xN-element matrix)
  • .NormalizationFactor - Normalization factors ((N/2-2)-element array)
  • .FreqAxis - Frequency Axis ((N/2-2)-element array)
  • .TimeAxis - Time Axis (N-element array)
  • .Crosstalk - Crosstalk matrix (N/2-2)x(N/2-2)-element matrix)

This structure can be then be passed directly to the apt function for computing the APT.

Since the APT is based on a time-domain to frequency-domain transformation, the APT kernel and the dipolar kernel obtained from the dipolarkernel function are not interchangeable.

Additional Settings

Additional settings can be specified via name-value pairs. All property names are case insensitive and the property-value pairs can be passed in any order after the required input arguments have been passed.

K = aptkernel(t,'Property1',Value1,'Property2',Value2,___)
-'ExcitationBandwidth' - Excitation bandwidth of the pulses in MHz.

If specified, its value is used in the compensation of limited excitation bandwidth of the experimental pulses. If not specified infinite excitation bandwidth is assumed.

Default: empty, corresponding to infinite excitation bandwidth

Example:

K = aptkernel(t,'ExcitationBandwidth',100)   % 100 MHz excitation bandwidth