trend

  1. M

    Dealing with temporal autocorrelation

    Hi, assume we have a measured value for each year from 1990-210, and we want to estimate a linear trend. Now there is a problem of autocorrelation, i.e., the measured values do not scatter randomly around the fittet line but rather resemble a "smooth function" wriggeling around the linear fit...
  2. T

    Normalising Search Data

    Hi Guys, Just want to start by saying great forums, some really useful stuff on here! I'm basically a statistics novice, though i did do a few subjects at uni many moons ago, so forgive me if I ask some stupid questions. And apologies if this isn't in the right area. I'm working on a data...
  3. R

    Using repeated measures change/trend as a predictor variable

    I have repeated measures of happiness for a sample of participants, and a single measure of satisfaction for each of the participants. I want to predict satisfaction from the repeated measures of happiness. To do so, I want to create a new variable, called happiness.change, which measures the...
  4. D

    What test to determine if 5 years of population data has a trend?

    Hello. I have population data for 5 years for several species of birds and I would like to know whether the populations are growing, staying stable, or decreasing. I am using R. So far, what I have been doing is creating a linear model of the count data (or log of the count data) by year...
  5. R

    Regression analysis: selecting TREND or FORECAST formula

    Hello, I am doing a regression analysis on average price increases from a PPI table, and my goal is to project a 2013 value using the average yearly value from 1985 - 2012. Excel gives me two formulas to do this -- TREND and FORECAST -- and both formulas appear to perform a regression...
  6. F

    the difference between non-stationary data and random data?

    what are the the difference between non-stationary data and random data? If we detrend a stationary data and make it non-stationary what will happen, will it be random?
  7. A

    Quantifying trends and patterns, which test to use?

    Attached is an image of some graphs showing the relationship between a factor which varies year on year, compared to various other factors. With many of the factors it is clear to see that there is a relation between them, however I'm unsure as to how best to show this quantitatively! Many...
  8. C

    Statistics Help

    Hello Everyone, I'm quite new to Stats and desperately need some help here. I'm working on resource planning with some data. The data that I have is... number of work items per day during the last year. Number of work items keep changing day to day and these numbers could be anywhere...
  9. I

    Forecasting with stochastic trends and unit roots

    I'm dealing with a set of data with a unit root and a stochastic trend for class and am trying to make a forecast. any help would be greatly appreciated
  10. S

    testing rates through time

    Hello all, this seems like it should be a simple questions but our team cannot find an answer to the question. If I have data set up like the following (the numbers are the percent that react positively to the drug): Drug 2007 2008 2009 2010 A 59 62 61 62 B 50 49 58 61...
  11. E

    Linear test for trend adjusted for cluster group?

    Hi, any help appreciated with this question. I have 8 time periods over which I wish to see if usage of a service changes using several demographics (age group, sex, HIV status, etc). There are about 2000 attendances in each time period from about 50 clusters. I can get proportions with 95%...