How to get a special coordinates {x,y} from a matrix in MATHEMATICA.

[76Ahmad]

Hello every one, this question for a mathematics experts...

Suppose we have the matrix

<br /> M =<br /> \left| {\begin{array}{cccc}<br /> 9 &amp; 6 &amp; 0 &amp; 1 \\<br /> 3 &amp; 7 &amp; 2 &amp; 5 \\<br /> 1 &amp; 0 &amp; 2 &amp; 8 \\<br /> 8 &amp; 8 &amp; 1 &amp; 0 \\<br /> \end{array} } \right|<br />

and we want to print only the coordinates that equal to 0

for our matrix it will be like that:(let say the raw is X, and the column is Y)

{3,1}
{2,3}
{4,4}

please help
thanks

 

[Bill Simpson]

In[1]:= M={{9,6,0,1},{3,7,2,5},{1,0,2,8},{8,8,1,0}}; Position[M,0]

Out[2]= {{1,3},{3,2},{4,4}}

Mathematica uses {row,column} instead of {column,row}

If you prefer your order for some reason then

In[3]:= Map[Reverse,Position[M,0]]

Out[3]= {{3,1},{2,3},{4,4}}

 

[76Ahmad]

Thanks Bill

It is work 100%