Search results

  1. noetsi

    time series problems

    I do mydata <- read_excel(file.choose()) mydata<- ts(mydata$Spend, start = c(2017, 7), frequency = 12) and I have no trouble I do mydatatr<- ts(mydata$Spend, start = c(2017, 7), end = c(2021,9), frequency = 12) and I get Error in mydata$Spend : $ operator is invalid for atomic vectors...
  2. noetsi

    residuals linearity

    There is really two issues here. First which of the many residuals that can be generated to look (this is from SAS). Second, I am trying to detect non-linearity (I tested for multicollinearity and there is none, with 5,000 plus points I don't care about heteroskedasticity or normality). But I...
  3. noetsi

    design question

    We have a service that we are trying to evaluate. We have a dependent variable of income gain. The problem is that those that get the service may vary in many ways from those who don't get the service (most of which we probably don't measure). For instance someone may have a more serious...
  4. noetsi

    restriction of range

    I am running a regression where the predictor, interval(formally anyhow see below), is how many times a customer had a new counselor. The dependent variable is how much income they earned. The dependent variable has a wide range of values. But there are relatively few levels of the predictor (in...
  5. noetsi

    Baffling data entry error

    library(readxl) library(forecast) mydata <- read_excel(file.choose()) # you chose what you want dataforTS mydatat<- ts(mydata$Spend, start = c(2014, 12), frequency = 12) I am absolutely baffled by an error that has never occurred before. Mydata imports the right number of records. But mydatat...
  6. noetsi

    sampling

    I know the general theory on finding out how many you need for an error range. But I have some questions I had not seen or forgot. What if you population is limited. We have a population that, depending on how they define it, might be as few as 40,000. Does it matter if the population is a...
  7. noetsi

    Useful R packages

    Everyone knows that I am learning R finally. :p I was curious what are some good R modules for beginner's. Simple regression is likely to be as complex as I will use. Graphical packages (for someone who will never be a master programmer) or things that interact with SQL would also be nice.
  8. noetsi

    Interpreting regression

    I have read many regression articles over the years (books as well) and the one thing that always puzzles me is the best way to interpret the results? I know slopes and odds ration (and the various measures of the model overall value ) and in honesty they seem pretty limited. I was wondering...
  9. noetsi

    Books on specific topic

    I need a good book that deals with fixed effect regression (or article since I doubt there is a book that covers this in detail). The federal government is using this to evaluate us and what they are doing/saying conflicts with my understanding of how fixed effects regression works. By fixed...
  10. noetsi

    Installation error

    They constantly change the protections where I work. I tried to install a new package (which seemed to work) but then got Error in unpackPkgZip(foundpkgs[okp, 2L], foundpkgs[okp, 1L], lib, libs_only, : ERROR: failed to lock directory...
  11. noetsi

    Index of R packages

    I have seen many partial lists on say time series. But I was wondering any suggestions on lists of which R package does which things (ideally with some annotation). I am sure there are many. I am of course a beginner.
  12. noetsi

    R information

    My unit has decided to learn R. None of them are primarily statistical analyst (they are SQL programmers/DBA). I suggested asking questions here. Any other sites they should go to for beginners (but awesome coders, they will learn very quickly).
  13. noetsi

    Removing confidence intervals in forecast package

    I am trying to remove confidence intervals in my forecast because I don't use them and its a pain to remove them in excel. Does anyone know code to tell the forecast package not to show them? I have not found a way on line
  14. noetsi

    Evaluating a regression model.

    An important issue I have done little on historically. "Variables entered in the development model were selected using stepwise backward-elimination approach, starting with all previously reported significant predictors found theoretically and practically to be associated with 90-day employment...
  15. noetsi

    Estimating effect of those not in the system

    We have an entire population we serve. But many never apply with us. We want to know if our services help those we serve or could serve. We can tell if services impact who we do serve, but I am not sure what this tells you about those you don't serve. I am not sure how, or if, you can analyze...
  16. noetsi

    Entering variables in blocks.

    I know a chi square difference test for nested models, but is that what is occurring here? They entered the predictors in two blocs. For demographic and socioeconomic factors, the likelihood ratio test for model goodness-of-fit was significant, χ2 (14,N= 14,229) = 1,900.75, p < 0.001...
  17. noetsi

    dropping variables from model

    I recently read a well regarded regression book where they strongly argued that one should not drop variables from a model because they were statistically insignificant (or really ever if they have theory behind them). But I see this all the time. "Considering that correlational analyses...
  18. noetsi

    practical regression books :)

    I am going to get laughed at if any of the moderators reads this. :p Over the years I have read a fair number of regression books. They are great for the theory of regression (if often beyond me). But I find myself dealing with issues that don't get addressed in such books much, and not in the...
  19. noetsi

    lasso issue

    I circled back to lasso because I have 48 variables and that is simply to much in my humble opinion for my data (the whole data set has about 3200 cases, but in many cases I slice it to as few as 48). I am not using k fold validation because it does not work well with too few cases. Nor am I...
  20. noetsi

    model test proc genmod

    I expected proc genmod to run a f or t test of the overall model. But if it did I can't find it. This is as close as I can find to what I expected to see, but there is no p value.