arrays - Matlab: Remove loop from code -

-

flow 4d double matrix fourth dimension 2. want implement loop without using loops.

essentially , each index in third dimension,, want divide flow1 square blocks of size block-size, calculate mean of values in fourth dimension of each block, assign values respective fourth dimension elements in block .

typical values [height width n block_size] = [ 480 640 100 8] . guaranteed block_size factor of both height , width 

[height,width,n,~]  = size(flow1); reduced_flow = zeros(size(flow1)); ii = 1:block_size:height     jj = 1:block_size:width         k = 1:n             reduced_flow(ii:ii+block_size-1,jj:jj+block_size-1,k,1) = mean(mean(flow1(ii:ii+block_size-1,jj:jj+block_size-1,k,1),1),2);             reduced_flow(ii:ii+block_size-1,jj:jj+block_size-1,k,2) = mean(mean(flow1(ii:ii+block_size-1,jj:jj+block_size-1,k,2),1),2);         end     end end

example

 flow1 = round(10*rand(4,4,2,2));  block_size = 2;  [flow1 reduced_flow]   ans(:,:,1,1) =       6.0000    4.0000    1.0000         0    4.0000    4.0000    2.2500    2.2500      6.0000         0    2.0000    6.0000    4.0000    4.0000    2.2500    2.2500           0    5.0000    1.0000    3.0000    3.2500    3.2500    2.7500    2.7500      6.0000    2.0000    2.0000    5.0000    3.2500    3.2500    2.7500    2.7500    ans(:,:,2,1) =       7.0000    1.0000    3.0000    4.0000    4.5000    4.5000    2.7500    2.7500      5.0000    5.0000    2.0000    2.0000    4.5000    4.5000    2.7500    2.7500      5.0000    9.0000    6.0000    9.0000    6.7500    6.7500    5.5000    5.5000      4.0000    9.0000    6.0000    1.0000    6.7500    6.7500    5.5000    5.5000    ans(:,:,1,2) =       1.0000    9.0000    7.0000    5.0000    3.2500    3.2500    7.5000    7.5000      2.0000    1.0000   10.0000    8.0000    3.2500    3.2500    7.5000    7.5000      7.0000   10.0000    3.0000    8.0000    6.2500    6.2500    4.0000    4.0000      3.0000    5.0000    4.0000    1.0000    6.2500    6.2500    4.0000    4.0000    ans(:,:,2,2) =       2.0000    3.0000    7.0000    7.0000    2.7500    2.7500    6.5000    6.5000      4.0000    2.0000    5.0000    7.0000    2.7500    2.7500    6.5000    6.5000      1.0000    2.0000    9.0000    6.0000    4.2500    4.2500    4.5000    4.5000      5.0000    9.0000    1.0000    2.0000    4.2500    4.2500    4.5000    4.5000

approach 1

flow11 = reshape(flow1,size(flow1,1),[]); fun = @(block_struct) mean2(block_struct.data); mat1 = blockproc(flow11,[block_size block_size],fun); mat2 = imresize(mat1,block_size ,'nearest'); reduced_flow = reshape(mat2,size(flow1));

approach 2

t1 = sum(reshape(sum(reshape(flow1,block_size,[])),height/block_size,block_size,[]),2)./block_size^2; t2 = reshape(t1,1,1,[]); t3 = t2(ones(1,block_size),ones(1,block_size),:,:); t4 = reshape(permute(t3,[1 3 2]),size(t3,1)*size(t3,3),[]); out = permute(reshape(t4,height,size(t4,1)/height,[]),[1 3 2]); reduced_flow = reshape(out,size(flow1));

Comments

Post a Comment

Popular posts from this blog

database - VFP Grid + SQL server 2008 - grid not showing correctly -

-
i having problem, have grid called "gridbasica" , this: thisform.gridbase.recordsource = "sgviemp" sgviemp cursor made executing select sqlserver command sqlexec. when want modify registry, go form , the update there. so, when come form grid, grid isnt grid anymore, big white rectangle. reading around said: delete recordsource , asingt again. thisform.gridbase.recordsource = "" *--i sqlexe here thisform.gridbase.recordsource = "sgviemp" i , works, but, when click button modify again cursos updated modify form doesnt load fields did first time. could me out that? thanks in advance. --------------- edit ------------------ i have been doing recommended: lnselect = select(0) n = sqlexec(thisform.conexion,"select emp_ccodigo codigo, emp_cnombre 'nombre o razon social', emp_cnumrif 'r.i.f' sgviempr","sgviemp1") set echo on suspend select sgviemp zap in sgviemp *-- browse *--zaps correct
Read more

jquery - Set jPicker field to empty value -

-
im using jpicker color selector in form. have clear value set window/icon 'no color selected' state. i've tried following: $(':input[name="color"]').val(''); //access value directly. (does not affect jpicker) 2: $.jpicker.list[0].color.active.val('hex', '', this); //set color black , input value 000000, instead of empty string 3: $.jpicker.list[0].color.active.val(null, '', this); //does nothing none of 3 methods seems behave properly. in advance. this works me :) $.jpicker.list[0].color.active.val('v', null); here example: http://jsfiddle.net/3up7n/
Read more

.htaccess - htaccess convert request to clean url and add slash at the end of the url -

-
ok , searched more 4 days , more 20 posts here in stach or in websites without kind of success first here htaccess file rewriteengine on rewriterule ^([a-za-z0-9_]+)/?$ index.php?page=$1 [nc] rewriterule ^([a-za-z0-9_]+)\/([a-za-z0-9_]+)\/?$ index.php?page=$1&action=$2 [nc] i tried many codes 1 worked me can call request , works me www.example.com/pagename => www.example.com/index.php?page=pagename here questions , please provide me information "in detail" understand code well 1- how convert request automatically www.example.com/index.php?page=pagename www.example.com/pagename 2- if tried add slash @ end shows me page without images or styling mean www.example.com/pagename => works www.example.com/pagename/ => doesn't work that's :) for first part need 301 rule this: rewritecond %{the_request} /index\.php\?page=([^\s&]+) [nc] rewriterule ^ /%1? [r=301,l] for second part use absolute path in css, js, images files r
Read more