step function

  1. P

    Model with discrete variables like step function

    I have some data and I want to use a model such as linear regression to describe the relationship between y and x. 2001 2002 2003 2004 2005 2006 2007 y: 0.1 0.4 0.2 0.5 0.8 0.9 0.2 x1: 0.4 0.4 0.4 0.4 0.5 0.5 0.5 x2: 0 0 0 0 0...
  2. M

    Large Negative AIC with Forward/Backward Selection

    Hello Everyone! I am a very new member to the forum, and extremely glad to find this lively discussion environment. I am a post-doc in astronomy, and with not that profound statistical background. I have come up with a bottleneck that like to consult with experts. So, let me introduce my...
  3. S

    step change

    Fir a step change model, is it a linear model ?
  4. V

    step function has too many interactions

    I am trying to run a step function with the model fullmodel=lm(Rate~Month*Depth*Moly*WatexCl*WatexSO4*WatexDOC*PWClumoles*PWSO4umoles*TotalFe*DaysInundated, data=FeRed2012) When I do step(fullmodel) it gives me a lot of interactions that I don't want to look at. For example it gives me...