matlab - How to add appropriate noise to a graph -


i have matlab graph. trajectory. want add noise graph. tried adding normal distribution noise. using rand. e.g.

x1=x+a*rand(size(x));

and y.

the results attached below. not want. gives me either scatter plot, or noisy plot. illustrated below. first row did, third row want.

enter image description here

different graph columns stand different standard deviation (value of a).

q. how obtain third type (row) of plot?

p.s. first row when use plot(...,".",markersize,1); , second row simple vector plot.

the issue want noise have characteristic. have many samples along curve, , you'd stay "connected". you'd smooth results, , want curve stay closed. so, in order: random walk noise keep points connected. low-pass-filtered noise keep curve smooth. , fix noise endpoint 0 (smoothly) ensure closed result. here's code generates 16 different kinds of noise (4x4), varying overall scale , overall amount of filtering. you'll have adjust both of these choices based on "sample rate" of data, , overall scale of shape.

% generate sample data [x,y] = pol2cart(0:0.01:2*pi, 1);  % pick set of 4 noise scale, , noise filter values scales = [.01 .05 .1 .5]; filterstrength = [.1 .5 .9 .98];  % plot 4x4 grid, picking different type of noise each 1 i=1:4     j=1:4         scale = scales(i);         f = filterstrength(j);          % generate noise x , y, filtering std 1 gaussian random         % walk         nx = filter(scale*(1-f), [1 -f], cumsum(randn(size(x))));         ny = filter(scale*(1-f), [1 -f], cumsum(randn(size(y))));          % want closed polygon, "detrend" result         % last point same first point         nx = nx - linspace(0,1,length(nx)).*(nx(end)-nx(1));         ny = ny - linspace(0,1,length(ny)).*(ny(end)-ny(1));          subplot(4,4,4*(i-1)+j);          % add noise         plot(x+nx,y+ny);     end end

other things vary: have infinite choices filter shape, affect style of deformation.


Comments

Post a Comment

Popular posts from this blog

curl - PHP fsockopen help required -

i trying work on cloudflare api , have found in documentation. unfortunately have no idea how can use in fsockopen or through curl. here example of post request. need know how can make request below data post using curl or fsockopen curl https://www.cloudflare.com/api_json.html -d 'a=cache_lvl' \ -d 'tkn=8afbe6dea02407989af4dd4c97bb6e25' \ -d 'email=sample@example.com' \ -d 'z=example.com' \ -d 'v=agg' here link cloudflare https://www.cloudflare.com/docs/client-api.html#s4.2 try one: $ch = curl_init("https://www.cloudflare.com/api_json.html"); curl_setopt($ch, curlopt_returntransfer,1); curl_setopt($ch, curlopt_followlocation, 1); curl_setopt($ch, curlopt_ssl_verifypeer,false); // handling of -d curl parameter here. $param = array( 'a' => 'cache_lvl', 'tkn' => '8afbe6dea02407989af4dd4c97bb6e25', 'email' => 'sample@example.com', 'z' =...
Read more

HTTP/1.0 407 Proxy Authentication Required PHP -

i working in restricted network/limited access internet. since have use proxy make web service call. here php code calling web service , response . $client = new soapclient("http: //www.xyz.com/abc/wsdls/login.wsdl", array("trace" => 1, "exceptions" => 1, 'proxy_host' => $proxy_host, 'proxy_port' => $proxy_port, 'proxy_login' => $proxy_login, 'proxy_password' => $proxy_password)); response is fatal error: uncaught soapfault exception: [wsdl] soap-error: parsing wsdl: couldn't load ' http://www.xyz.com/abc/wsdls/login.wsdl ' : failed load external entity if copy url error message , paste in browser(with same proxy settings) works. 2nd scenario is, if pass values instead of variables giving me diffarant response $client = new soapclient("http: //www.xyz.com/abc/wsdls/login.wsdl", array("trace" => 1, "exceptions" => 1, 'proxy_host' ...
Read more

c# - Resource not found error -

i have problem accessing method on homecontroller. show code of method : [httpget] public actionresult decriptidentifiantetredirige(string login_crypter, string mdp_crypter) { string loginacrypter = _globalmanager.protegemotdepasse(login_crypter); string mdpacrypter = _globalmanager.protegemotdepasse(mdp_crypter); user userapp = new models.user(login_crypter, mdp_crypter); if (userapp.authentificationvalidee(userapp.userlogin, userapp.password)) { session["name"] = userapp.userlogin; return redirecttoaction("accueil", "home"); } else { return redirecttoaction("validerauthentification", "home"); } } then in routeconfig.cs wrote route : routes.maproute( name: "authentificationapresdecryptage", url: "{controller}/{action}/{login_crypter}/{mdp_crypter}", defaults: new...
Read more