pdf - Finding The Max Value from Plotted Density Function (Kernel Density Estimation) in R -


i have data i'm assuming comes distribution , i'm trying estimate distribution. right i'm using package kernsmooth in r gaussian kernel , using package's dpik() function automatically select bandwidth. (i assume uses amise or sort, please let me know if there better auto-bandwidth selection process) i'm interested in, though, finding x-value corresponds highest peak in distribution...this seems simple thing me , put off trivial earlier on frustration, i'm hitting snags. bkde() function in kernsmooth passes set of (x,y) coordinates map out distribution algorithm has estimated. know linear search through data find max y-value , grab corresponding x-value but, writing function may called in automated process, feel inefficient. inefficient since bkde() gives lot of values.

my other idea attempt fit curve , take derivative , set equal 0 sounds may inefficient well. maybe density() better function use here?

please let me know if there efficient way this...i plan little bit of inference on distributions find. such finding cutoff points chop off percentage of tail on either side (i.e. confidence intervals) , finding expected value. vague plan use monte carlo techniques or attempt draw distribution idea areas bootstrapping techniques. on methods of these appreciated.

using:

> require(kernsmooth) loading required package: kernsmooth kernsmooth 2.23 loaded copyright m. p. wand 1997-2009 > mod <- bkde(faithful$waiting) > str(mod) list of 2  $ x: num [1:401] 22.7 23 23.2 23.4 23.7 ...  $ y: num [1:401] 3.46e-08 1.17e-07 1.40e-07 1.68e-07 2.00e-07 ...

is not efficient enough?

> which(mod$y == max(mod$y)) [1] 245

density() similar, returns 512 values of density evaluate @ 512 regular intervals of x.

in both functions number of points returned can controlled. see argument gridsize in bkde() , n in density(). of course, precision of approach depend on density of points @ kde estimated won;t want set low.

my gut tells me may spend awful lot more time thinking , implementing more efficient approach spend going above simple solution.


Comments

Post a Comment

Popular posts from this blog

jquery - Invalid Assignment Left-Hand Side -

i trying assign class tag via jquery, resulting in error through firebug says "invalid assignment left-hand side" on fourth line below. <cfoutput> $('.pngfix a').each(function(index) { var hreflink = $(this).attr("href"); if (hreflink.tolowercase() = '../audio.cfm') { $(this).addclass('audioimg'); } }); </cfoutput> looking around online, looks syntax problem, don't seem see it... any tips? thanks if (hreflink.tolowercase() = '../audio.cfm') that attempts assign value, rather check equality. change = operator == .
Read more

java - Play! framework 2.0: How to display multiple image? -

i need display gallery of photos. here template: @(photos: list[photo]) @title = { <bold>gallery</bold> } @main(title,"photo"){ <ul class="thumbnails"> @for(photo <- photos) { <li class="span3"> <a href="#" class="thumbnail"> <img src="@photo.path" alt=""> </a> </li> } </ul> } and here controller method: public static result getphotos() { return ok(views.html.photo.gallery.render(photo.get())); } and here photo bean : @entity public class photo extends model { @id public long id; @required public string label; public string path; public photo(string path, string label) { this.path = path; this.label = label; } private static finder<long, photo> find = new finder<long, photo>( long.class, photo.class); public static list<phot...
Read more

gmail - Is there any documentation for read-only access to the Google Contacts API? -

i want read-only access user's google contacts. there stackoverflow member wanted this, , received following answer : yes, there is, use https://www.googleapis.com/auth/contacts.readonly scope , "view contacts". this exchange reference read-only access google contacts can find using google. simply using access token obtained attempt read usual google contacts api (i.e. https://www.google.com/m8/feeds ) fails insufficient permissions. similarly, using google contacts api on new target fails 404 errors (for example https://www.googleapis.com/auth/contacts.readonly/default/full ). is there documentation anywhere on how use api, or permissible way access google contacts api full read-write access?
Read more