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Diffstat (limited to 'sourcecodes/bnt-master/netlab3.3/dist2.m')
| -rw-r--r-- | sourcecodes/bnt-master/netlab3.3/dist2.m | 31 |
1 files changed, 31 insertions, 0 deletions
diff --git a/sourcecodes/bnt-master/netlab3.3/dist2.m b/sourcecodes/bnt-master/netlab3.3/dist2.m new file mode 100644 index 00000000..b5f1c646 --- /dev/null +++ b/sourcecodes/bnt-master/netlab3.3/dist2.m @@ -0,0 +1,31 @@ +function n2 = dist2(x, c) +%DIST2 Calculates squared distance between two sets of points. +% +% Description +% D = DIST2(X, C) takes two matrices of vectors and calculates the +% squared Euclidean distance between them. Both matrices must be of +% the same column dimension. If X has M rows and N columns, and C has +% L rows and N columns, then the result has M rows and L columns. The +% I, Jth entry is the squared distance from the Ith row of X to the +% Jth row of C. +% +% See also +% GMMACTIV, KMEANS, RBFFWD +% + +% Copyright (c) Ian T Nabney (1996-2001) + +[ndata, dimx] = size(x); +[ncentres, dimc] = size(c); +if dimx ~= dimc + error('Data dimension does not match dimension of centres') +end + +n2 = (ones(ncentres, 1) * sum((x.^2)', 1))' + ... + ones(ndata, 1) * sum((c.^2)',1) - ... + 2.*(x*(c')); + +% Rounding errors occasionally cause negative entries in n2 +if any(any(n2<0)) + n2(n2<0) = 0; +end \ No newline at end of file |