scilab submatrix incorrectly defined -

i stuck @ creating matrix of matrix (vector in case)

what have far

index = zeros(size(a)) // matrix isn't important question indexindex = 1; rows=1:length(r)      columns=1:length(k)                if(a(rows,columns)==x)            v=[rows columns]; // create vector holding row + column            index(indexindex) = v(1,2) // want store these vectors            indexindex = indexindex + 1         end     end end 

i have tried various ways of getting information out of v (such v(1:2)) nothing seems work correctly.

in other words, i'm trying array of points.

thanks in advance

i not understand question exactly. size of a? x, k , r? under assumptions,

using list

you use list

// create matrix a = zeros(8,8)  //initialize list index = list();  // dimensions of rows = size(a,1); cols = size(a,2);  x = 0;  row=1:rows     col=1:cols              if(a(row,col)==x)            // create vector holding row , col            v=[row col];             // append list using $ (last index) + 1            index($+1) = v          end     end end 

single indexed matrices

another approach make use of fact multi-dimensional matrix can indexed single value.

for instance create random matrix named a:

-->a = rand(3,3)  =  0.6212882    0.5211472    0.0881335   0.3454984    0.2870401    0.4498763   0.7064868    0.6502795    0.7227253  

access first value:

-->a(1)  ans  =      0.6212882   -->a(1,1)  ans  =      0.6212882   

access second value:

-->a(2)  ans  =      0.3454984    -->a(2,1)  ans  =      0.3454984 

so proves how single indexing works. apply problem , knocking out for-loop.

// create matrix a = zeros(8,8)  //initialize array of indices index = [];  // dimensions of rows = size(a,1); cols = size(a,2);  x = 0;  i=1:length(a)                if(a(i)==x)         // append list using $ (last index) + 1         index($+1) = i;      end end 

without for-loop

if need values adhere condition this

values = a(a==x); 

be carefull when comparing doubles, these not (un)equal when expect.