NA coefficient in linear regression R -


i have run simulation r.

basically have create set of variables (x) in matrix nxp first variable has value 1, , other 23 variables has random values randomly extracted n(0,1). vector beta of length 24 has first 2 values 1 , rest 0. vector epsilon of length 24 extracted n(0,1). after create variable y is: y=x %*% beta + epsilon. select variable of x has max(cor(abs(xj,y))) j goes (3,24) , have run model y ~ x1 + x2 + xj , see results.

> set.seed(123) >  > n=25 p=24 b=seq(1,1000) >  > x <- cbind(matrix(1,nrow=25,ncol=1),matrix(rnorm(25*23),nrow=25, > ncol=23)) beta <- t(t(c(1,1,rep(0,22)))) eps <- t(t(rnorm(25))) >  > y <- x %*% beta + eps >  > j<-seq(3,24) m <- which.max(abs(cor(x[,j],y))) >  > newx <- as.data.frame(cbind(y,x[,1], x[,2], x[,m+2])) anyna(newx[,2]) > mod <- lm(v1 ~ . , data=newx) > summary(mod)  call: lm(formula = v1 ~ ., data = newx)  residuals:      min       1q   median       3q      max  -1.42575 -0.90957  0.06547  0.38879  2.39707   coefficients: (1 not defined because of singularities)             estimate std. error t value pr(>|t|)     (intercept)   1.1235     0.2421   4.641 0.000126 *** v2                na         na      na       na     v3            0.6803     0.2775   2.452 0.022612 *   v4           -0.5943     0.3036  -1.957 0.063101 .   --- signif. codes:  0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1  residual standard error: 1.085 on 22 degrees of freedom multiple r-squared:  0.3958,     adjusted r-squared:  0.3408  f-statistic: 7.205 on 2 , 22 df,  p-value: 0.003919

everything works fine, can see estimated coefficient v2, coefficient variable x1, composed 1, na. don't understand why have na result, values in variable listed numeric , there's no missing value.

if can me understand, thanks!


Comments

Post a Comment

Popular posts from this blog

Is there a better way to structure post methods in Class Based Views -

i'm using class based views in django , never specify url in ajax calls , omit action parameter in form because know these requests go through post method of class based view. notice view - profile page make many requests depending on user updating on page - post method become convoluted , if/else mess example: def post(self, request, *args, **kwargs): # handle user changing available date if request.post.get('availabledate') != none: self.updateavailabledate(request) return jsonresponse({'result':'success'}) if request.post.get('newprojectname') != none: creative_user = creativeuserprofile.objects.get(id = request.user.id) project = project.create_project(creative_user, request.post['newprojectname']) project.save() return jsonresponse({'projectid': project.id }) if request.post.get('projectimage') != none , request.files['file']: proj...
Read more

performance - Why is XCHG reg, reg a 3 micro-op instruction on modern Intel architectures? -

i'm doing micro-optimization on performance critical part of code , came across sequence of instructions (in at&t syntax): add %rax, %rbx mov %rdx, %rax mov %rbx, %rdx i thought had use case xchg allow me shave instruction , write: add %rbx, %rax xchg %rax, %rdx however, dimay found agner fog's instruction tables , xchg 3 micro-op instruction 2 cycle latency on sandy bridge, ivy bridge, broadwell, haswell , skylake. 3 whole micro-ops , 2 cycles of latency! 3 micro-ops throws off 4-1-1-1 cadence , 2 cycle latency makes worse original in best case since last 2 instructions in original might execute in parallel. now... cpu might breaking instruction micro-ops equivalent to: mov %rax, %tmp mov %rdx, %rax mov %tmp, %rdx where tmp anonymous internal register , suppose last 2 micro-ops run in parallel latency 2 cycles. given register renaming occurs on these micro-architectures, though, doesn't make sense me done way. why wouldn't register renamer ...
Read more

c# - Asp.net web api : redirect unauthorized requst to forbidden page -

im trying redirect unauthorized request forbidden page instead i'm getting forbidden page in response body , how can fix ? here's startup class : app.createperowincontext(storecontext.create); app.createperowincontext<applicationusermanager>(applicationusermanager.create); app.createperowincontext<applicationsigninmanager>(applicationsigninmanager.create); app.usecookieauthentication(new cookieauthenticationoptions { authenticationtype = defaultauthenticationtypes.applicationcookie, expiretimespan = timespan.fromdays(30), }); app.useexternalsignincookie(defaultauthenticationtypes.externalcookie); app.usetwofactorsignincookie(defaultauthenticationtypes.twofactorcookie, timespan.fromminutes(5)); app.usetwofactorrememberbrowsercookie(defaultauthenticationtypes.twofactorrememberbrowsercookie); the method im trying reach : [httpget] [authorize(roles = "admin")] public string getcurrentusername() { return userman...
Read more