V1.0  - 1st version

V1.1  - Minor typos in some comments corrected
      - fieldsum.m added now includes 1/r path loss for pseudo-near field calcs see
        help fieldsum. Old version still exists as fieldsum_old.m

      - Problem with calc_theta.m and calc_phi.m using the normalise='yes' option
        has been corrected. (String compare error rather than numeric)	

V2.0  - Correction to unit vector re-normalisation in fieldsum.m, didn't affect results in
        earlier version, just keeps internal calculations tidy.

      - Re-organised some internal house-keeping by adding new directory element_indexing. 
        Made adding new element models a bit easier.

      - Added new aperture element models :
        aprect  Rectangular aperture, uniform distribution
        apcirc  Circular aperture, uniform distribution
        wgr     Rectangular waveguide, TE10 distribution
        wgc     Circular waveguide, TE11 distribution
        dish    Parabolic dish aperture, adjustable amplitude taper

      - list_array now has Real and Imag columns for element excitations 

      - New directory beam_synthesis added :
      - modtaylor.m    Outputs excitations for lin array given number of sources 
                       and 1st sidelobe level required. (Modified Taylor Distribution)
      - chebwin1.m     Outputs excitations for lin array given number of sources and
                       level of all sidelobes. (Chebyshev distribution)


      - Circular polarisation plotting is now possible LHCP, RHCP for all 2D/3D plots
        and Axial Ratio for 3D plots.

      - plot_pattern3d1 function added, same as plot_pattern3D except
        with an additional parameter, figure number. 

      -	New function cpol_array.m added. Circularly polarises an existing array
        by duplicating array elements. Copied elements can be set to be orthogonal
        in phase and orientation with respect to the originals. 

      - n-bit quantisation for beam steering operations added. See squint_array.m 
        function in the Geometry_Construction directory

        Changes for V2.0 shouldn't affect any scripts written using the standard
        V1.1 functions - all the original example and validation files still work OK. 

V2.1  - More general tidying and corrections in help/comments, rather a lot actually, 
        apologies for that.
        X-axis label in some Phi plots corrected, was 'Theta' doh!

      - functions plot_theta_statvar.m and plot_phi_statvar.m added to show the effect
        of normally distributed variations in amplitude and phase excitations.


   
V2.2  - Potential divide by zero error in dipole models trapped, thanks to Jon for 
        spotting this.
 
      - Binomial amplitude distribution added to beam_synthesis directory
        see exdist.m for comparisons with other distributions.

      - 3D pattern routine re-written, there was a dynamic range problem 
        (colour scale itself was OK) when using very small elements 
        (e.g. lambda/20 dipole). Hopefully it is easier to follow and generally 
        more robust now. Functionally, there is no change.

      - Examples added showing the use of small elements to model current/field
        distributions on wires/apertures. exloop.m and exap1.m

      - Example showing large aperture application (2-dish interferometer) and 
        identifying upper limit for apperture size that ArrayCalc can cope with.
        Max aperture approx 1000 Lambda. See exinter.m
      
      - Error in place_element.m corrected, text output reported to screen was 
        angle information rather than position. 

V2.3  - plot_theta/phi_statvar help files corrected (normalisation options should
        have been 'yes' or 'no').  

      - sumcode.m help corrected, too much cut and paste.

      - Examples moved to separate 'Examples' directory, display list by typing 'exlist'
        Comments in examples and various other files added to and tidied up.

      - Fourier beam synthesis added, fourier1.m together with examples exfourier1/2/3.m

V2.4  - Potential divide by zero warning trapped in rectangular patch model.
        
      - The dB power value returned by modtaylor function corrected, error did not affect
        internal calculations as these use linear volts.  
      
      - The taywin_array function changed slightly, gives sidelobes closer to the requested
        value for arrays with regular spacing.
         
      - Fieldsum modified very slightly, the sign of the circular polarisation flag 
        now determines the hand of polarisation: CPflag=1 (RHCP) and CPflag=-1 (LHCP) 
        Only affects inherently circularly polarised helements, currently only the helix.

      - New plotting function plot_geopat3D added, plots 3D pattern and array 
        geometry on the same plot.

      - New plotting functions plot_theta_geo1 and plot_phi_geo1 added, for adding single
        pattern cuts to the 3D geometry plot.

      - The functions plot_theta, plot_phi, plot_squint_theta and plot_squint_phi now
        add pattern cuts to the 3D geometry plot in figure1 by default. This should
        help identify the requested plots.
  
      - Thanks to Piro for spotting some problems with the Taylor distribution and suggestions
        for improvements.

      - User manual now included with documention. New directory added for the documentation.

      - Some new example files added.



        Minor post 2.4 release changes.

      - File interp.m renamed to interpl.m to avoid potential conflict with interp.m as
        defined in the Mathworks Signal Processing Toolbox. Reference to 'interp' in
        SUMCODE.m also changed to 'interpl'.(Should correct problems with running Ex3a/b)

      - File interp_geom.m modified to display sub-array geometry.

      - ExTestSUB1 and ExTestSUB2 examples added to show the use of sub-arrays.

      - ExParab and Exparabpol added to illustrate simplified modelling of reflectors.