regression - LINEST function in Microsoft excel; curve fitting tri-quadratic equation -



regression - LINEST function in Microsoft excel; curve fitting tri-quadratic equation -

im trying curve fit first graph in set of 4 using linest. curve needs graph of 3, possible 4, variables: suction pressure level (sp), od temp, id wb temp, , possible id db temp (other graphs didnt need db work, may not needed here). isnt simple linest, tri- or quad-quadratic linest.

attempted: 2nd, 3rd grade linest fits using corresponding x,y values first graph.

how do this?

ok if have info in table format can utilize next formula

=linest(knownys, knownxs^{1, 2, 3})

when come in select 4 cells across, set in formula , come in ctrl+shift+enter. values returns a1,a2,a3, , b going left right if formula has next equation: y=a1*x^3+a2*x^2+a3*x+b.

another alternative fit curves using chart trendline , can exponents there.

source

edit

based on edits suggest find improve statistical software excel 1 alternative utilize solver. set bunch of cells constants wanted a1,a2,b1,b2 etc.

then have columns independent variables (od temp, id wb temp, etc) column known ys, column calculated ys , error column (known y - calcy)^2 sum error column , run solver minimize sum of error.

calc y =a1*odtemp^2+a2*odtemp+b1*wbtemp^2+b2*wbtemp+c or whatever form formula needs fit.

excel regression

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