Mercurial > hg > octave-lyh
changeset 10851:5b33a5777ab0
isargout optimization in histc
author | Jaroslav Hajek <highegg@gmail.com> |
---|---|
date | Wed, 04 Aug 2010 21:07:21 +0200 |
parents | 6c57bd7d0808 |
children | 47e013327758 |
files | scripts/statistics/base/histc.m |
diffstat | 1 files changed, 23 insertions(+), 19 deletions(-) [+] |
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--- a/scripts/statistics/base/histc.m +++ b/scripts/statistics/base/histc.m @@ -134,28 +134,32 @@ ## Zero invalid ones (including NaNs). data < edges(1) are already zero. idx(! (data <= edges(end))) = 0; - iidx = idx; + ## Don't accumulate the histogram if not needed. In that case, + ## histc() is just a (Matlab-compatible) wrapper for lookup. + if (isargout (1)) + iidx = idx; - ## In case of matrix input, we adjust the indices. - if (! isvector (data)) - nl = prod (sz(1:dim-1)); - nn = sz(dim); - nu = prod (sz(dim+1:end)); - if (nl != 1) - iidx = (iidx-1) * nl; - iidx += reshape (kron (ones (1, nn*nu), 1:nl), sz); + ## In case of matrix input, we adjust the indices. + if (! isvector (data)) + nl = prod (sz(1:dim-1)); + nn = sz(dim); + nu = prod (sz(dim+1:end)); + if (nl != 1) + iidx = (iidx-1) * nl; + iidx += reshape (kron (ones (1, nn*nu), 1:nl), sz); + endif + if (nu != 1) + ne =length (edges); + iidx += reshape (kron (nl*ne*(0:nu-1), ones (1, nl*nn)), sz); + endif endif - if (nu != 1) - ne =length (edges); - iidx += reshape (kron (nl*ne*(0:nu-1), ones (1, nl*nn)), sz); - endif - endif + + ## Select valid elements. + iidx = iidx(idx != 0); - ## Select valid elements. - iidx = iidx(idx != 0); - - ## Call accumarray to sum the indexed elements. - n = accumarray (iidx(:), 1, nsz); + ## Call accumarray to sum the indexed elements. + n = accumarray (iidx(:), 1, nsz); + endif endif