python - PCA how to plot effect of one component -



python - PCA how to plot effect of one component -

edit @ bottom containing solution

i performed pca on dataset, resulting in eigenvectors, eigenvalues , mean. want plot effects of varying 1 principal component can't figure out how. want create plot this:

http://i.stack.imgur.com/6lqaa.png

so formula for should

mean + pb

with p eigenvectors , b

b = p.t * (x - mean)

but don't know utilize x. possibility according active shape model paper cootes that

b = (b1 b2 .. bt).t

so vector of weights. makes more sense me, way have weight of first b set -3 * sqrt(eigenvalue) , plot result. i'm having dimensionality problems way.

my input info pca [20, 160], returns [160] mean, [160, n] n amount of principal components want retain, let's take 5. , [n] eigenvalues. way can't pb because p [160] should dotproduct [160]? i'm pretty confused on how this, help appreciated!

edit: ok figured out problem. when trying plot effect of first principal component, taking first column of eigenvectors, mistake.

what should take of eigenvectors p, in case [160, 5], , create new vector b dimension [5]. b consists of zeros, except on index of principal component wish change, set e.g. -2 * sqrt(eigenvalue_i), plot effect of varying principal component i, 2 standard deviations left. result in

x = mu + p * b

with mu = mean, p finish set of eigenvectors, , b vector containing weights of variation.

python components analysis pca principal

Comments

Post a Comment

Popular posts from this blog

php - Android app custom user registration and login with cookie using facebook sdk -

php - Android app custom user registration and login with cookie using facebook sdk - i developing android application in users need register , log in using facebook. approximately, flow. open app first time, authenticate facebook, data, send info server create them business relationship in application, start session new business relationship in server, cookie perform later interactions. so far good. what need know wich info have send server, can able identify users when log in seccond time. because need start session in server , send cookie android app farther interactions. i'm using php server side language. i thinking getting getaccesstoken() in android facebook sdk, pass server on business relationship creation , storing in android app. but can't manage how login users on sec time utilize app. any suggestions ? in advance ! to uniquely identify user within app, should create request /me , user's id. guaranteed unique , remain con
Read more

django - Access session in user model .save() -

django - Access session in user model .save() - is possible access current session in user model .save()? pseudo code of want achieve: # users.models.py def save(self, *args, **kwargs): created = true if self.pk: created = false super(abstractuser, self).save(*args, **kwargs) # post-save if created: look_for_invite_in_session_and_register_if_found(self, session) seems wrong in architecture. shouldn't access request in models layer. work request must done in view. can this: user, created = abstractuser.objects.get_or_create(name=name) if created: look_for_invite_in_session_and_register_if_found(user, request.session) django session
Read more

php - .htaccess Multiple Rewrite Rules / Prioritizing -

php - .htaccess Multiple Rewrite Rules / Prioritizing - here current htaccess file: rewriteengine on rewritecond %{http_host} !^www\.website\.com [nc] rewritecond %{http_host} ([^.]+)\.website\.com [nc] rewriterule ^(.*)$ http://www.website.com/gotourl.php?urlid=?%1 [l] rewriterule ^(\w+)$ ./gotourl.php?urlid=$1 [nc,l] rewriterule ^(\w+)/$ ./gotourl.php?urlid=$1 [nc,l] the website in question url shortener i'm working on testing/developing , personal use. above code may not ideal i'm not familiar .htaccess , made via googling , testing. want url shortening aspect: http://website.com/1234 -> http://website.com/gotourl.php?urlid=1234 http://website.com/1234/ -> http://website.com/gotourl.php?urlid=1234 the problem cannot figure out how ignore directories. want specific directories go specific pages: http://website.com/img (or) http://website.com/img/ -> http://website.com/img.php http://website.com/img/1234 (or) http://website.com/
Read more