factor

  1. M

    Factor Analysis (categorical variables)

    Hi everyone, I need to run a factor analysis on a few nominal variables. They have no defined order, therefore, I cannot use polychoric correlations to create a matrix. My variables are coded such that: 1- respondent 2- husband 3- In laws and so on. I have eight variables and will...
  2. M

    Simulation for logistic regression in R

    Dear All, I would like to simulate data for logistic regression and I need to have below variables x1=numeric (mean=25,std=5) x2=numeric (mean=50,std=10) x3=factor variables with 5 levels x4=factor variable with 3 levels x5=factor variable with 2 levels How can I do that? Thank you
  3. T

    One observation per factor level combination in regression

    Hi... I was wondering if you can perform multiple linear regression with a mix of categorical and quantitative variables, if you only have one observation per combination of the levels of your factors in the regression model? And how do you interpret predictions? Thanks in advance!
  4. R

    subset data

    why can't I subset data that have values from -9998 to 1000. I want to subset the data with only values greater than 0. I used the following code: ECC1<-subset(ECC, value > 0, select = c (sensor, value)) The error says: In Ops.factor(value, 0): > not meaningful for factor. Any clue...
  5. A

    Analysing ranked data

    I had following question in my questionnaire: Rank following factors: price, quality, advertisement, brand, reference from 1 (very important) to 5 (least important) that influenced on your buying decision process. Which approaches may be used in order to measure most important factors? I...
  6. J

    What is a anti-image correlation matrix?

    Hello, I am currently doing an homework on Factor Analysis and PCA in SPSS and I have to present the Anti-image matrix and explain what it is. However, after having searched on google, all I found was this : The anti-image of the correlation matrix is the negative of the partial correlations...
  7. S

    "Unknown Factor" needed

    Good Day All I am currently handling a temperature estimation project related to drop of temperature for different type of liquid in storage tanks. The scenario is like this - There are 14 Tanks filled with different type of liquid (max 4 types). I am also taking Air Temp in consideration. So...
  8. E

    What kind of ANOVA is this?

    Ok...I know this may be a silly question but I am extremely bad at stats. I have an experiment with two IVs and a control group. ie. one group must perform a task after seeing someone complete it before them, another group must perform a task after watching someone attempt (and not finish)...
  9. G

    Help... new database from a database multiplied for an expansion factor

    how can i creat a new database from a database multiplied for an expansion factor using Stata...?
  10. A

    Factor Analysis

    Hello! I run a Factor Analysis and got 14 factors with an Eigenvalue above 1! The first 5 factors explain most of the variance (Eigenvalue >2) and the remaining 9 factors have an eigenvalue around 1.5 What shall I do? Shall I keep all 14 factors or extract only the first 5 that explain...
  11. S

    collapsing a factor to see summarized levels of the other one (ANOVA?)

    Hi, in 2-factor analysis, is it possible to "collapse" a factor in order to have a clear view of the effect of the levels of the other factor? Which numerical techniques are available for this purpose? (maybe a code snippet in R?). Is it possible with ANOVA? thanks!
  12. T

    Missing Level on linear model tests

    So I'm an R newbie, we're attempting to use it for some regression analysis at work on some of our data sets. To start we wanted to take a very simple data set that we had and attempt to fit a linear model to it. The problem that I'm running into is that once I import the data file and...
  13. C

    Linear Regression: how to tell if factors "disagree"?

    I use a regression as my predictor. Let's say my regression is (y=a1 x1 + a2 x2 + a3 x3) y=a_1 x_1+a_2 x_2+a_3 x_3 I realized that in practise, when my prediction is way off, it's usually because one factor significantly skewed the prediction. For example, x1,x2 are both slightly negative...
  14. alfred

    Compare 7 different conditions with ANOVA

    Hello there, In my SPSS dataset each subject is assigned a certain score upon 7 different conditions: therefore in SPSS I have 7 columns and 20 lines, each line representing a subject/case, each column reporting a value (score). The data is normal and I want to compare the scores between the...
  15. L

    Factor Analysis

    I'm trying to run a Factor Analysis on a large environmental data set with a combination of data types, and i'm having some difficulties. I get a Warning message listing a number of possibilities of what could have gone wrong. One option is that I have variables with zero variance. i've run a...