1. S

    Three-way PCA

    Hi all, Does anybody have experience with 3-way PCA? Is there any example using SAS? I am not sure if I understand how it is different from the classical PCA... Thank you
  2. M

    How to do Regression with many replicates of y at each level of x?

    Hi follows, I have data that looks as follows: X, y1, y2, y3, y4 0, 54.241, 127.728, 127.73802, 127.73802 31, 65.132, 127.729, 127.73787, 127.73792 59, 65.364, 127.729, 127.73782, 127.73789 Where y1-y4 are just independent...
  3. J

    Lack-of-fit for repeated measures

    Greetings, I'm looking to run a lack-of-fit test on repeated measures data. To summarize my problem, I want to test whether an eight-factor regression model fails to adequately predict 15 (nominal) condition means (measured in response times). Thus, each participant has an observed mean score...
  4. B

    Having problems with CATREG for big and small data sets and defining scaling level.

    0 down vote favorite I am facing with an interesting problem here. I have a data set containing mixed nature of independent variables (some are nominal, some are ordinal, some are scale). The dependent variable is ordinal. I thought if I use CATREG in SPSS then I am going to get only one...
  5. B

    Test for and remedy of multicollinearity in logistic regression with categorical IVs

    I was searching over net how can I test the presence of multicollinearity and what is its remedy in case the IVs are categorical in a logistic regression. I am a SPSS user and found these two links over net which can be useful. But having problem to understand them. Can anyone see it and tell me...
  6. R

    How to perform pooled cross-sectional time series analysis?

    For 86 companies and for 103 days, I have collected (i) tweets (variable `hbVol`) about each company and (ii) pageviews for the corporate wikipedia page (`wikiVol`). The dependent variable is each company's stock trading volume (`stockVol0`). My data is structured as follows: company...
  7. R

    How to perform regression on panel-data with timelag in SPSS?

    For my thesis, I have gathered search volume data ("svi") from Google and message data from Twitter ("tweets" is the number of daily tweets) for serveral companies ("comp"). The variable "tradevol" is the trading volume in the stock of a company, as taken from Yahoo! Finance. "svi" and "tweets"...
  8. S

    Fitting a model with Bernoulli/Binomially distributed data

    I am used to fitting data to estimate parameters in a model f(x,A) where x is my data point and A is the parameter(s) to be determined. To achieve this I usually use chi-squared fitting, so I am minimizing \chi^2 = \sum \frac{(y_i - f(x_i,A))^2}{\sigma_i^2}. I have recently been given an almost...
  9. L

    the t-values for regression coefficients

    How can I calculate the t-values of the regression coeffs if I have the sample size and the correlation matrix only? Is this possible? Thanks in advance.
  10. V

    Regression Validation

    Hi, How do I validate the regression model.Is it just by comparing the actual values against the values that I obtain thr regression equation. Thanks in advance.