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interp

PURPOSE ^

INTERP interpolate the values in the input AO(s) at new values specified by the input parameter list.

SYNOPSIS ^

function varargout = interp(varargin)

DESCRIPTION ^

 INTERP interpolate the values in the input AO(s) at new values specified by the input parameter list.

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

 DESCRIPTION: INTERP interpolate the values in the input AO(s) at new values
              specified by the input parameter list.

 CALL:        b = interp(a, pl)

 INPUTS:      a  - input array of AOs
              pl - parameter list with the keys 'vertices' and 'method'

 OUTPUTS:     b  - output array of AOs

 PARAMETERS:  'vertices'     - new set of vertices to interpolate on.
              'method'       - one of:
                   'nearest' - nearest neighbour
                   'linear'  - linear interpolation
                   'spline'  - spline interpolation
                   'cubic'   - shape-preserving piecewise cubic interpolation

 REMARK:      Matrix cdata objects are not supported.

 VERSION:     $Id: interp.m,v 1.10 2007/11/26 14:48:13 ingo Exp $

 The following call returns a parameter list object that contains the
 default parameter values:

 >> pl = interp(ao, 'Params')

 HISTORY: 05-06-07 M Hewitson
             Creation

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

CROSS-REFERENCE INFORMATION ^

This function calls: This function is called by:

SUBFUNCTIONS ^

SOURCE CODE ^

0001 function varargout = interp(varargin)
0002 % INTERP interpolate the values in the input AO(s) at new values specified by the input parameter list.
0003 %
0004 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
0005 %
0006 % DESCRIPTION: INTERP interpolate the values in the input AO(s) at new values
0007 %              specified by the input parameter list.
0008 %
0009 % CALL:        b = interp(a, pl)
0010 %
0011 % INPUTS:      a  - input array of AOs
0012 %              pl - parameter list with the keys 'vertices' and 'method'
0013 %
0014 % OUTPUTS:     b  - output array of AOs
0015 %
0016 % PARAMETERS:  'vertices'     - new set of vertices to interpolate on.
0017 %              'method'       - one of:
0018 %                   'nearest' - nearest neighbour
0019 %                   'linear'  - linear interpolation
0020 %                   'spline'  - spline interpolation
0021 %                   'cubic'   - shape-preserving piecewise cubic interpolation
0022 %
0023 % REMARK:      Matrix cdata objects are not supported.
0024 %
0025 % VERSION:     $Id: interp.m,v 1.10 2007/11/26 14:48:13 ingo Exp $
0026 %
0027 % The following call returns a parameter list object that contains the
0028 % default parameter values:
0029 %
0030 % >> pl = interp(ao, 'Params')
0031 %
0032 % HISTORY: 05-06-07 M Hewitson
0033 %             Creation
0034 %
0035 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
0036 
0037 ALGONAME = mfilename;
0038 VERSION  = '$Id: interp.m,v 1.10 2007/11/26 14:48:13 ingo Exp $';
0039 
0040 % Check if this is a call for parameters
0041 if nargin == 2
0042   in = char(varargin{2});
0043   if strcmp(in, 'Params')
0044     varargout{1} = getDefaultPL();
0045     return
0046   elseif strcmp(in, 'Version')
0047     varargout{1} = VERSION;
0048     return
0049   end
0050 end
0051 
0052 % Collect input ao's, plist's and ao variable names
0053 in_names = {};
0054 for ii = 1:nargin
0055   in_names{end+1} = inputname(ii);
0056 end
0057 
0058 [as, ps, invars] = collect_inputs(varargin, in_names);
0059 
0060 % check plist
0061 if isempty(ps)
0062   pl = getDefaultPL();
0063 else
0064   pl = combine(ps, getDefaultPL);
0065 end
0066 
0067 
0068 % Get parameters
0069 vertices = find(pl, 'vertices');
0070 method  = find(pl, 'method');
0071 
0072 %-----------------------
0073 % Loop over input AOs
0074 bs = [];
0075 for j=1:numel(as)
0076 
0077   a = as(j);
0078 
0079   %----------------------------
0080   % Get data
0081   [x,y] = get_xy_values(a.data);
0082 
0083   %----------------------------
0084   % Interpolate this vector
0085   if ~isempty(x)
0086     % for tsdata, fsdata and xydata objects
0087     y = interp1(x,y,vertices, method, 'extrap');
0088   else
0089     % for cdata object
0090     y = interp1(y,vertices, method, 'extrap');
0091   end
0092 
0093   %----------------------------
0094   % Make output AO/cdata
0095   d = a.data;
0096 
0097   d = set_xy_axis(d, vertices, y.');
0098 
0099   d = set(d, 'name', sprintf('%s(%s)', method, d.name));
0100 
0101   h = history(ALGONAME, VERSION, pl, a.hist);
0102   h = set(h, 'invars', invars(j));
0103 
0104   % make output analysis object
0105   b = ao(d, h);
0106 
0107   % set name
0108   b = setnh(b, 'name', sprintf('%s(%s)', method, invars{j}));
0109 
0110   % add to outputs
0111   bs = [bs b];
0112 
0113 end
0114 
0115 % Reshape the ouput to the same size of the input
0116 bs = reshape(bs, size(as));
0117 
0118 % Set outputs
0119 varargout{1} = bs;
0120 
0121 %--------------------------------------------------------------------------
0122 % Get default params
0123 function plo = getDefaultPL()
0124 
0125 plo = plist();
0126 plo = append(plo, param('vertices', []));
0127 plo = append(plo, param('method', 'spline'));
0128 
0129 
0130 
0131 
0132 
0133 % END

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