Binary Serach of rows of M-by-N Matrix

Binary Search that is based on sum of column values of rows of input M-by-N Matrix
2.1K 次下载
更新时间 2009/7/9

查看许可证

Binary Serach of rows of M-by-N Matrix
Search is based on sum of column values of rows of input M-by-N Matrix
i.e. Rows of input Matrix must already be sorted in ascending order
based on sum of their column values. i.e.
row1sum<row2sum<...rowjsum<...rowmsum
where rowjsum=sum(mat(j,:),2) (i.e sum of column values)

If mat is not sorted use following two statments to sort rows of mat
according to sum of column values
matwithsum=sortrows([sum(mat,2),mat],1);
mat=matwithsum(:,2:end);

INPUT:
mat: Matrix contains values such as
[x1, y1,..., zn;
x2, y2,..., zn;
...
xm, ym,..., zn];

srow: row that is to be searched in mat

OUTPUT:
Using following different value of parameter 'type' following output can be return
1. 'first': returns 'indvec1' i.e index of first occured row in mat that matches to srow.

2. 'all': returns 'indvec1' i.e indices of all rows in mat that matches to srow.

3. 'last': returns 'indvec1' i.e index of last row in mat that matches to srow.

4. 'allcolsum': returns 'indvec1' i.e indices of all k rows of mat such that
sum(mat(j,:),2)=sum(srow,2),
where 1<=j<=k

5. 'colsumandval': return two index vector first is similar to return by "allcolsum" and second is similiar to return by "all' option.

Note that if we are searching e.g. [5 4 2] by option 'first' then there may be many rows whose column sum is equal to given row e.g. [2 4 5],[0 0 11],[4 2 5], [5 4 2] but only
last row i.e. [5,4,2] matches in all columns to given row to be searched.
-------------------------
bsearchmatrows.m (main program)
bsearchmatrowsTest1.m (simple test program)
bsearchmatrowsTest2.m (compare performance with MATLAB builtin metod index=find(ismember(mat,srow, 'rows'));
-------------------
For large data this search is extremely faster than MATLAB built in methods

引用格式

Dr. Murtaza Ali Khan (2024). Binary Serach of rows of M-by-N Matrix (https://www.mathworks.com/matlabcentral/fileexchange/9095-binary-serach-of-rows-of-m-by-n-matrix), MATLAB Central File Exchange. 检索时间: .

MATLAB 版本兼容性
创建方式 R13
兼容任何版本
平台兼容性
Windows macOS Linux
类别
Help CenterMATLAB Answers 中查找有关 Direct Search 的更多信息

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!
版本 已发布 发行说明
1.1.0.0

BSD License

1.0.0.0