Hi I am trying to build a regression model. My data looks like this: A B C D E 1 1 1 2.57 5 2 0 0 1.64 3 0 5 1 4.8 1 1 3 0 3.56 168 1 1 1 2.13 1 0 3 1 5 168 2 0 0 7.75 28 4 0 2 2.85 168 3 0 1 1.89 6 1 1 1 2.33 3 3 2 2 1.77 168 1 0 0 1.38 0.04 0 6 1 4.57 168 2 2 2 2.86 1 3 1 1 4.11 168 3 0 2 3 84 1 1 1 2.5 56 where E is a response variable and A, B, C, D are predictor variables. Below are commands which I enter in R: str (mydata) mydata.lm = lm (E ~ 1, data = mydata) # to create a blank model add1(mydata.lm, mydata, test='F') # to add the best predictor variable to the blank model However at this point the message appears: Warning messages: 1: In model.matrix.default(Terms, m, contrasts.arg = object$contrasts) : the response appeared on the right-hand side and was dropped 2: In model.matrix.default(Terms, m, contrasts.arg = object$contrasts) : problem with term 4 in model.matrix: no columns are assigned What does it mean ? Could you please help ? -- View this message in context: http://r.789695.n4.nabble.com/building-a-regression-model-tp4654701.html Sent from the R help mailing list archive at Nabble.com.
building a regression model
3 messages · dada, Rui Barradas, Mario Bourgoin
Hello, The "error" is just a warning, these are not the same thing. And the warning says that you're giving a wrong scope argument, one that includes the response. See ?add1. Argument 'scope' is "a formula giving the terms to be considered for adding or dropping." And you're passing the entire data.frame, not just the regressors. To get rid of the warning, try the following. add1(mydata.lm, ~ A + B + C + D, test='F') Hope this helps, Rui Barradas Em 04-01-2013 23:53, dada escreveu:
Hi I am trying to build a regression model. My data looks like this: A B C D E 1 1 1 2.57 5 2 0 0 1.64 3 0 5 1 4.8 1 1 3 0 3.56 168 1 1 1 2.13 1 0 3 1 5 168 2 0 0 7.75 28 4 0 2 2.85 168 3 0 1 1.89 6 1 1 1 2.33 3 3 2 2 1.77 168 1 0 0 1.38 0.04 0 6 1 4.57 168 2 2 2 2.86 1 3 1 1 4.11 168 3 0 2 3 84 1 1 1 2.5 56 where E is a response variable and A, B, C, D are predictor variables. Below are commands which I enter in R: str (mydata) mydata.lm = lm (E ~ 1, data = mydata) # to create a blank model add1(mydata.lm, mydata, test='F') # to add the best predictor variable to the blank model However at this point the message appears: Warning messages: 1: In model.matrix.default(Terms, m, contrasts.arg = object$contrasts) : the response appeared on the right-hand side and was dropped 2: In model.matrix.default(Terms, m, contrasts.arg = object$contrasts) : problem with term 4 in model.matrix: no columns are assigned What does it mean ? Could you please help ? -- View this message in context: http://r.789695.n4.nabble.com/building-a-regression-model-tp4654701.html Sent from the R help mailing list archive at Nabble.com.
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