Initial Commit

octave/shim/discretize.m

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+function bins = discretize (x, edges, varargin)
+  %DISCRETIZE  Which bin each value falls in, for explicit edges (R2015a+).
+  %
+  %  An owuitools compatibility shim; see contains.m for the policy, and
+  %  histcounts.m for why explicit edges only and for the edge convention,
+  %  which this shares: the last bin is closed, everything outside the
+  %  edges is NaN, and so is NaN itself.
+
+  if (nargin < 2)
+    error ('discretize: not enough input arguments');
+  end
+  if (~isnumeric (edges) || isscalar (edges))
+    error (['discretize: this sandbox supports discretize(x, edges) with explicit ' ...
+            'edges only - MATLAB''s automatic binning is not reproduced here.']);
+  end
+  if (~isempty (varargin))
+    error ('discretize: this shim takes only (x, edges) - no categorical or option arguments');
+  end
+  if (~isnumeric (x) && ~islogical (x))
+    error ('discretize: x must be numeric');
+  end
+  edges = edges(:).';
+  if (numel (edges) < 2 || any (diff (edges) <= 0))
+    error ('discretize: edges must be a vector of at least two increasing values');
+  end
+
+  v = double (x);
+  bins = nan (size (v));
+  last = numel (edges) - 1;
+  for i = 1:last
+    if (i < last)
+      in = v >= edges(i) & v < edges(i + 1);
+    else
+      in = v >= edges(i) & v <= edges(i + 1);
+    end
+    bins(in) = i;
+  end
+end