Re: [R] what is the difference between using function predict() and coef() in prediction
X8 = c(0.42808332, 0.14058333, 0.30558333, 0.09558333, 0.01808333, -0.09191666, -0.11441666, -0.12941666, 0.13808333, -0.31691666, 0.25308333 ,-0.20941666 ,0.02808333, -0.04441667, -0.43691666) xy.lm = lm(Y~X8) z = predict(xy.lm,list(X8=X8)) sz = coef(xy.lm)[1]+(coef(xy.lm)[2])*X8 is the same result in this step but when use the prediction as T8=c(-0.05691667, -0.09441666 , 0.31308333 ,-0.59941665 ,-0.33941666 ,-0.64441665,-0.55691665 ,-0.01191667 ,0.22558333, -0.30691666 ,0.97808331 , 0.49808332,-0.30941666 ,0.41808332 , 0.42308332) zz = predict(xy.lm,list(T8=T8)) ss = coef(xy.lm)[1]+(coef(xy.lm)[2])*T8 here gives me different value and zz = z = sz i do not know the reason for that what i understand about predict() act exactly like using coef() but now do not know the difference thank you for respond -- View this message in context: http://r.789695.n4.nabble.com/what-is-the-difference-between-using-function-predict-and-coef-in-prediction-tp4173961p4180577.html Sent from the R help mailing list archive at Nabble.com. __ R-help@r-project.org mailing list 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.
Re: [R] what is the difference between using function predict() and coef() in prediction
X8 = c(0.42808332, 0.14058333, 0.30558333, 0.09558333, 0.01808333, -0.09191666, -0.11441666, -0.12941666, 0.13808333, -0.31691666, 0.25308333 ,-0.20941666 ,0.02808333, -0.04441667, -0.43691666) Y =c(370.6 , 887.6 ,3610.88333 , 435.1 , 1261.38333 , -741.11667,-3231.36667 ,-708.36667 ,-646.36667, -3652.86667 ,-2196.11667 ,-5552.61667,-92.11667, -1635.86667 ,-3264.61667) xy.lm = lm(Y~X8) z = predict(xy.lm,list(X8=X8)) sz = coef(xy.lm)[1]+(coef(xy.lm)[2])*X8 is the same result in this step but when use the prediction as T8=c(-0.05691667, -0.09441666 , 0.31308333 ,-0.59941665 ,-0.33941666 ,-0.64441665,-0.55691665 ,-0.01191667 ,0.22558333, -0.30691666 ,0.97808331 , 0.49808332,-0.30941666 ,0.41808332 , 0.42308332) zz = predict(xy.lm,list(T8=T8)) ss = coef(xy.lm)[1]+(coef(xy.lm)[2])*T8 here gives me different value and zz = z = sz i do not know the reason for that what i understand about predict() act exactly like using coef() but now do not know the difference thank you for respond -- View this message in context: http://r.789695.n4.nabble.com/what-is-the-difference-between-using-function-predict-and-coef-in-prediction-tp4173961p4180628.html Sent from the R help mailing list archive at Nabble.com. __ R-help@r-project.org mailing list 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.
Re: [R] what is the difference between using function predict() and coef() in prediction
On Dec 10, 2011, at 11:48 AM, tony333 wrote: X8 = c(0.42808332, 0.14058333, 0.30558333, 0.09558333, 0.01808333, -0.09191666, -0.11441666, -0.12941666, 0.13808333, -0.31691666, 0.25308333 ,-0.20941666 ,0.02808333, -0.04441667, -0.43691666) xy.lm = lm(Y~X8) z = predict(xy.lm,list(X8=X8)) sz = coef(xy.lm)[1]+(coef(xy.lm)[2])*X8 is the same result in this step but when use the prediction as T8=c(-0.05691667, -0.09441666 , 0.31308333 ,-0.59941665 ,-0.33941666 ,-0.64441665,-0.55691665 ,-0.01191667 ,0.22558333, -0.30691666 , 0.97808331 , 0.49808332,-0.30941666 ,0.41808332 , 0.42308332) zz = predict(xy.lm,list(T8=T8)) The first T8 should be..^^ X8 zz = predict(xy.lm,data.frame(X8=T8)) ss = coef(xy.lm)[1]+(coef(xy.lm)[2])*T8 identical(unname(zz), ss) [1] TRUE ss = coef(xy.lm)[1]+(coef(xy.lm)[2])*T8 here gives me different value and zz = z = sz i do not know the reason for that what i understand about predict() act exactly like using coef() but now do not know the difference If you give predict alist or data.fram whose name is different than that of the origianl variable ist will be ignored. thank you for respond -- View this message in context: http://r.789695.n4.nabble.com/what-is-the-difference-between-using-function-predict-and-coef-in-prediction-tp4173961p4180577.html Sent from the R help mailing list archive at Nabble.com. __ R-help@r-project.org mailing list 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. David Winsemius, MD West Hartford, CT __ R-help@r-project.org mailing list 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.
Re: [R] what is the difference between using function predict() and coef() in prediction
Hi Did you find any difference? The results shall be same (with only rounding error). Can you show us some example where you get substantial difference? Regards Petr i do not know what is the difference between predict() and coef() i use the two function give me different result zz = predict(xy.lm,list(T8=T8)) ss = coef(xy.lm)[1]+(coef(xy.lm)[2])*T8 where is t8 is the data used in prediction did not use in the fitting in training sample where every sample is 15 value -- View this message in context: http://r.789695.n4.nabble.com/what-is-the- difference-between-using-function-predict-and-coef-in-prediction- tp4173961p4173961.html Sent from the R help mailing list archive at Nabble.com. __ R-help@r-project.org mailing list 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 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] what is the difference between using function predict() and coef() in prediction
i do not know what is the difference between predict() and coef() i use the two function give me different result zz = predict(xy.lm,list(T8=T8)) ss = coef(xy.lm)[1]+(coef(xy.lm)[2])*T8 where is t8 is the data used in prediction did not use in the fitting in training sample where every sample is 15 value -- View this message in context: http://r.789695.n4.nabble.com/what-is-the-difference-between-using-function-predict-and-coef-in-prediction-tp4173961p4173961.html Sent from the R help mailing list archive at Nabble.com. __ R-help@r-project.org mailing list 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.
