Matlab - How to improve efficiency of two port matrix calculations? -

-

i'm looking way speed simple 2 port matrix calculations. see below code example i'm doing currently. in essence, create [nx1] frequency vector first. loop through frequency vector , create [2x2] matrices h1 , h2 (all functions of f). bit of simple matrix math including matrix left division '\' later, , got result pb [nx1] vector. problem loop - takes long time calculate , i'm looking way improve efficiency of calculations. tried assembling problem using [2x2xn] transfer matrices, mtimes operation cannot handle 3-d multiplications.

can please give me idea how can approach such calculation without need looping through f?

many thanks: svenr

% calculate frequency , wave number vector

f = linspace(20,200,400); w = 2.*pi.*f;

% calculation each frequency w

for i=1:length(w)     h1(i,1) = {[1, rho*c*k(i)^2 / (crad*pi); 0,1]};    h2(i,1) = {[1, 1i.*w(i).*mp; 0, 1]};    hzin(i,1) = {h1{i,1}*h2{i,1}};    temp_mat = hzin{i,1}*[1; 0];    zin(i,1) = temp_mat(1,1)/temp_mat(2,1);    temp_mat= h1{i,1}\[1; 1/zin(i,1)];    pb(i,1) = temp_mat(1,1); ub(i,:) = temp_mat(2,1); end

assuming length(w) == length(k) returns true , rho , c, crad, mp scalars , in last line ub(i,1) = temp_mat(2,1) instead of ub(i,:) = temp_mat(2,1);

 temp = repmat(eyes(2),[1 1 length(w)]);  temp1(1,2,:) = rho*c*(k.^2)/crad/pi;  temp2(1,2,:) = (1i.*w)*mp;  h1 = permute(num2cell(temp1,[1 2]),[3 2 1]);  h2 = permute(num2cell(temp2,[1 2]),[3 2 1]);  hzin =  cellfun(@(a,b)(a*b),h1,h2,'uniformoutput',0);  temp_cell = cellfun(@(a,b)(a*b),h1,repmat({[1;0]},length(w),1),'uniformoutput',0);  zin_cell = cellfun(@(a)(a(1,1)/a(2,1)),temp_cell,'uniformoutput',0);  zin = cell2mat(zin);  temp2_cell = cellfun(@(a)({[1;1/a]}),zin_cell,'uniformoutput',0);  temp3_cell = cellfun(@(a,b)(pinv(a)*b),h1,temp2_cell);  temp4 = cell2mat(temp3_cell);  p(:,1) = temp4(1:2:end-1);  ub(:,1) = temp4(2:2:end);

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