time

  1. D

    Multiple Lineair Regression - Another variable needed ?

    Hey, I'm doing a research on 3 variables, exchange rates, macroeconomic news and net speculative positions. So far I have a regression with exchange rates changes being the dependent variable, news and positions being the independent variables. The exchange rate changes are measures in a...
  2. D

    Molding Time in SAS

    How can I build a time variable into my model? I am building a model in SAS and I want to use time of day as a way to predict Y. "Are people more willing to pay for something based on what time of day it is?" I expect people are more willing to pay for something at different parts of the day...
  3. M

    Aggregate data in 1 minute bars

    Hi I have been looking at many ways of aggregating data, but none seem to fit on the dataset I have. See below. What I would like to do is aggregate the data based on 1 minute time bars. The time variable is seconds after midnight, so 1:3599.999 second intervals, with the total amount of...
  4. A

    Trends analysis

    Hi, Which is the most appropriate method to use when we are trying to assess trends over time for a nominal multicategory variable? For example, if I want to examine if there is a trend over 10 years in composition of population by their insurance status who makes a hospital visit. So...
  5. D

    How to compare trends of different curves?

    Hello everyone, i'm a newbie here...i'll try to explain, as well as i can, my stat problem: I have to compare trends of sleep during time of three different (beetween factor) groups of subjects (see childlike picture). How can i easily do that? in particular, i would like to highlight that the...
  6. B

    PCA on time series

    Hi, excuse my poor english... I need to reduce number of indicators (and to perform a PCA) on dataset: year ind(1) ind(2) ... ind(n) 2000 x(1,1) x(1,2) ... x(1,n) ..... 2010 x(11,1) x(11,2) ... x(11,n) x(i,j) are quantitative values about indicators like production, resources, ecc. How...
  7. B

    Software to extract statistics (per month, per year) from a time series

    Hi. I work with rain (precipitation) time series, and would like to extract time statistics: - precipitations per month - precipitations per year - precipitations per month and year - precipitations per hour - precipitations per month and hour - mean precipitation, deviation, ... I...
  8. D

    Negative linear regression (time value)

    hey all, I'm working on a basic program for calculating the time remaining as a battery of a device runs down from 100% (full) to 0% (empty). In theory this is a negative linear regression, but when I use standard formulas I get large positive time values. I assume I need to solve for x...
  9. J

    Interpreting main effects in long. mixed model when interactions w/ time are in model

    I am running a mixed effects longitudinal model with linear and quadratic time effects and a continuous outcome. I have a covariate that has a significant interaction with time-squared, so obviously the linear interaction and its main effect are left in the model. When interactions are in the...
  10. LycianSage

    Continuous or Discrete: Likert-type Time

    Hi! Sorry for asking a very basic question. I'm not good at stats and can't reach someone who knows. I searched the net with many different keywords but failed to find any answers. So, Are these variables Discrete or Continuous? 1. Approximately how long have you had your MySpace...
  11. K

    SAS Date and time

    Hi There I would like to know if there is a way to know when a particular variable was populated first. For example if I have a table with one of the variables as "First Name", is it possible to know when was the "First Name" variable populated for that particular record. May be a time...
  12. W

    Comparing time-based regressions

    Hello! I have a ton of temperature data over time for 38 different subjects (over 100,000 lines of data) that I ran regressions on for each subject. I want to compare how much people's temperature varies with time and use that as a variable (ex: is there a correlation between people with a...