No, you need to specify the inputs corresponding to the next value in order to obtain a production for that point. Read ?predict.lm or whatever function is appropriate for your model about the newdata argument. -- Sent from my phone. Please excuse my brevity.
On October 15, 2016 8:24:35 AM PDT, mviljamaa <mvilja...@kapsi.fi> wrote: >My conception of prediction intervals is the following: > >"a prediction interval gives an interval within which we expect next >y_i >to lie with a specified probability" > >So when using predict() for my model: > >predict(fit4, interval="prediction")[1:20,] > >I get: > > fit lwr upr >1 491.1783 381.3486 601.0081 >2 515.4883 405.7128 625.2638 >3 581.5957 447.9569 715.2344 >4 522.4979 412.5086 632.4872 >5 604.6008 492.2796 716.9221 >6 520.2881 410.3108 630.2655 >7 620.7379 507.9045 733.5713 >8 621.0925 505.8731 736.3119 >9 527.1810 417.2760 637.0859 >10 519.4651 406.1622 632.7680 >11 622.0051 512.0082 732.0021 >12 536.6924 424.3415 649.0434 >13 504.8618 394.9034 614.8202 >14 545.5920 433.6530 657.5309 >15 475.6153 362.4383 588.7923 >16 462.5341 350.6090 574.4593 >17 559.0888 448.1212 670.0564 >18 544.0051 432.0583 655.9519 >19 471.1450 355.2377 587.0523 >20 604.3028 470.6925 737.9130 > >Now since the prediction interval gives the interval within which the >_next_ y_i will fall, then how to read the above results? Does the >previous row's "lwr" and "upr" refer to the next row's "fit"'s >interval? > >______________________________________________ >R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see >https://stat.ethz.ch/mailman/listinfo/r-help >PLEASE do read the posting guide >http://www.R-project.org/posting-guide.html >and provide commented, minimal, self-contained, reproducible code. ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
