I am sorry,
I have a problem. When I use the "predict" function I am always obtaining the same result and I don't know why. In adittion, the intercept and the residual values I get are wrong too. std: [1] 0.068 0.117 0.167 0.269 0.470 0.722 Concentration: [1] 3.90625 7.81250 15.62500 31.25000 62.50000 125.00000 replica1: Replica.1 1 0.080 2 1.325 3 1.309 4 1.072 5 1.595 6 1.384 replica2: Replica.2 1 0.098 2 1.335 3 1.271 4 1.187 5 1.569 6 1.268 regresion <- lm(std ~ Concentration, mydata): Call: lm(formula = std ~ Concentration, data = mydata) Residuals: 1 2 3 4 5 6 -0.035531 -0.007440 0.000742 0.019106 0.052834 -0.029711 Coefficients: Estimate Std. Error t value Pr(>|t|) (Intercept) 0.0826219 0.0208118 3.97 0.016539 * Concentration 0.0053527 0.0003532 15.15 0.000111 *** --- Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1 Residual standard error: 0.0366 on 4 degrees of freedom Multiple R-squared: 0.9829, Adjusted R-squared: 0.9786 F-statistic: 229.6 on 1 and 4 DF, p-value: 0.0001106 > predict(regresion, replica1, int = "p") fit lwr upr 1 0.1035309 -0.012098349 0.2191602 2 0.1244399 0.009958707 0.2389212 3 0.1662580 0.053716164 0.2787998 4 0.2498941 0.139724612 0.3600636 5 0.4171663 0.305409665 0.5289230 6 0.7517107 0.614489312 0.8889322 > predict(regresion, replica2, int = "p") fit lwr upr 1 0.1035309 -0.012098349 0.2191602 2 0.1244399 0.009958707 0.2389212 3 0.1662580 0.053716164 0.2787998 4 0.2498941 0.139724612 0.3600636 5 0.4171663 0.305409665 0.5289230 6 0.7517107 0.614489312 0.8889322 So, anyone knows what is happening to me? Thank you very much! This e-mail comes from CIC bioGUNE. The e-mail and any files transmitted with it are confidential and intended solely for the use of the individual or entity to whom they are addressed. Any unauthorised dissemination or copying of this e-mail or its attachments, and any use or disclosure of any information contained in them, is strictly prohibited and may be illegal. If you have received this e-mail in error, please notify or telephone + 34 944 06 13 00 and delete it from your system. Please consider the environment before printing this email [[alternative HTML version deleted]] ______________________________________________ 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.