Mercurial > hg > octave-nkf
changeset 7655:ea2344c4140b
rectint.m: vectorize and add tests
author | bill@denney.ws |
---|---|
date | Thu, 27 Mar 2008 14:48:36 -0400 |
parents | 48edf48cd4dc |
children | d448ac8a4874 |
files | scripts/ChangeLog scripts/geometry/rectint.m |
diffstat | 2 files changed, 79 insertions(+), 35 deletions(-) [+] |
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--- a/scripts/ChangeLog +++ b/scripts/ChangeLog @@ -1,3 +1,7 @@ +2008-03-27 Bill Denney <bill@denney.ws> + + * geometry/rectint.m: Vectorize and add more tests. + 2008-03-27 John W. Eaton <jwe@octave.org> * plot/__axis_label__.m: Use name of caller in error message.
--- a/scripts/geometry/rectint.m +++ b/scripts/geometry/rectint.m @@ -43,49 +43,89 @@ error ("rectint: a must have 4 columns"); elseif (columns (b) != 4) error ("rectint: b must have 4 columns"); + elseif any ([a(:,3:4);b(:,3:4)](:) < 0) + error ("rectint: all widths and heights must be > 0") + endif + + ## This runs faster if the number of rows of a is greater than the + ## number of rows of b. Swap them and transpose to make it run + ## faster. + swapinputs = false (); + if (rows (a) > rows (b)) + tmp = a; + a = b; + b = tmp; + swapinputs = true (); endif area = zeros (rows (a), rows (b)); - for i = 1:rows (area) - r1 = a(i,:); - for j = 1:columns (area) - r2 = b(j,:); - area(i,j) = (overlap (r1([1, 3]), r2([1, 3])) - * overlap (r1([2, 4]), r2([2, 4]))); - endfor + r1 = [a(:,1:2) a(:,1:2)+a(:,3:4)]; + r2 = [b(:,1:2) b(:,1:2)+b(:,3:4)]; + for i = 1:columns (area) + ## Find the location of each point relative to the other points. + r1x1small = r1(:,1) < r2(i,1); + r1x1large = r1(:,1) > r2(i,3); + r1x1mid = (r1(:,1) >= r2(i,1)) & (r1(:,1) <= r2(i,3)); + r1x2small = r1(:,3) < r2(i,1); + r1x2large = r1(:,3) > r2(i,3); + r1x2mid = (r1(:,3) >= r2(i,1)) & (r1(:,3) <= r2(i,3)); + + r1y1small = r1(:,2) < r2(i,2); + r1y1large = r1(:,2) > r2(i,4); + r1y1mid = (r1(:,2) >= r2(i,2)) & (r1(:,2) <= r2(i,4)); + r1y2small = r1(:,4) < r2(i,2); + r1y2large = r1(:,4) > r2(i,4); + r1y2mid = (r1(:,4) >= r2(i,2)) & (r1(:,4) <= r2(i,4)); + + ## determine the width of the rectangle + ## r1 completely encloses r2 + area(r1x1small & r1x2large,i) = r2(i,3) - r2(i,1); + ## the range goes from r2x min to r1x max + mask = r1x1small & r1x2mid; + area(mask,i) = r1(mask,3) - r2(i,1); + ## the range goes from r1x min to r2x max + mask = r1x1mid & r1x2large; + area(mask,i) = r2(i,3) - r1(mask,1); + ## the range goes from r1x min to r1x max + mask = r1x1mid & r1x2mid; + area(mask,i) = r1(mask,3) - r1(mask,1); + + ## determine the height of the rectangle + ## r1 completely encloses r2 + area(r1y1small & r1y2large,i) .*= r2(i,4) - r2(i,2); + ## the range goes from r2y min to r1y max + mask = r1y1small & r1y2mid; + area(mask,i) .*= r1(mask,4) - r2(i,2); + ## the range goes from r1y min to r2y max + mask = r1y1mid & r1y2large; + area(mask,i) .*= r2(i,4) - r1(mask,2); + ## the range goes from r1x min to r1x max + mask = r1y1mid & r1y2mid; + area(mask,i) .*= r1(mask,4) - r1(mask,2); + endfor -endfunction - -function amt = overlap (r1, r2) - - ## Determine whether two ranges overlap. Ranges are given as [value - ## offset] - amt = 0; - - ## Make sure that the values are in order. - r1 = sort ([r1(1), r1(1)+r1(2)]); - r2 = sort ([r2(1), r2(1)+r2(2)]); - - ## Is the first point in range 1 in the middle of range 2? - p1 = sum (r1(1) <= r2) == 1; - ## is the second? - p2 = sum (r1(2) <= r2) == 1; - if (p1) - if (p2) - amt = r1(2) - r1(1); - else - amt = r2(2) - r1(1); - endif - elseif (sum (r1(2) < r2) == 1) - amt = r1(2) - r2(1); + if swapinputs + area = area'; endif endfunction ## Tests +## Exactly overlapping +%!assert(rectint([0 0 1 1], [0 0 1 1]), 1) +## rect2 completely enclosed by rect1 +%!assert(rectint([-1 -1 3 3], [0 0 1 1]), 1) +## rect1 completely enclosed by rect2 +%!assert(rectint([0 0 1 1], [-1 -1 3 3]), 1) +## rect1 right and top in rect2 +%!assert(rectint([-1 -1 1.5 1.5], [0 0 1 1]), 0.25) +## rect2 right and top in rect1 +%!assert(rectint([0 0 1 1], [-1 -1 1.5 1.5]), 0.25) +## no overlap - shared corner %!assert(rectint([0 0 1 1], [1 1 2 2]), 0) -%!assert(rectint([0 0 1 1], [0.5 0.5 2 2]), 0.25) -%!assert(rectint([0 0 1 1;0.5 0.5 1 1], [1 1 2 2]), [0;0.25]) -%!assert(rectint([1 1 2 2], [0 0 1 1;0.5 0.5 1 1]), [0 0.25]) - +## no overlap - shared edge +%!assert(rectint([0 0 1 1], [0 1 2 2]), 0) +## Correct orientation of output +%!assert(rectint([0 0 1 1;0.5 0.5 1 1;-1 -1 2 2], [1 1 2 2]), [0;0.25;0]) +%!assert(rectint([1 1 2 2], [0 0 1 1;0.5 0.5 1 1;-1 -1 2 2]), [0 0.25 0])