In general, a trend is an observable pattern in the data.

learn more… | top users | synonyms

0
votes
0answers
7 views

Testing for a non-zero, monotonic trend amongst 3 groups in a repeated-measures design

For each subject, we repeatedly measure 3 conditions for a scalar dependent variable. The research hypothesis is that there is a monotonic positive trend - that is, either 1<2<3 or 1=2<3 or ...
0
votes
0answers
25 views

Trend Decomposition

I have a time series of daily advertising revenue. The series shows various trends that are noticeable at long-term scales, such as over the course of a few months, but also many smaller ...
0
votes
0answers
37 views

Which trend test should I use?

Sorry if this is a newbie question. For example, I have 5 groups and each group has different amount of people, and I got the face recognition score (in percentage, between 0 and 1) for all people in ...
0
votes
2answers
25 views

Forecasting methods for monthly sales

I have to make predictions about sales on a monthly base and I already have historical data from January 2011 until June 2015. What forecasting method should I use if my data is influenced by ...
0
votes
1answer
33 views

Confusing results on kpss.test() for stationarity

I've got a dataset which clearly shows a trend. However, I want to assess wether this trend is deterministic or stochastic. If I understood it right, I would need to use differences if the trend is ...
0
votes
0answers
13 views

Can I use simple statistical tests for trend in crime data?

I want to see the trend in crime data e.g. incidences of thefts are increasing or decreasing with time. For this purpose, can I use simple statistical tests like linear regression, mann kendall etc ...
0
votes
1answer
38 views

Augmented Dickey Fuller Test with trend

I'm performing an analysis of the log GDP of Switzerland using eViews and I have to do an ADF-Test to check wheter the series is stationary or not. From the graph, I'll say that the series is not ...
0
votes
0answers
17 views

How can I filter marketing campaigns out of my decomposed seasonal data?

I've recently jumped into the deep end of statistical analysis of revenue. I've learned a ton about statistics, probability, decomposition (stl), and the Python and R languages. I feel like I'm ...
2
votes
0answers
33 views

When is a single data point enough to be considered a trend in the data?

In the general case, when collecting data points at disparate points in time (such as once per day or two), under what conditions can a single low data point be considered a downwards trend in the ...
0
votes
0answers
31 views

Can anyone explain what is happening in the stl function of R?

I am recently working with seasonal-trend decomposition. Yet I am not that familiar with the approach that R is using. Can anyone one kindly explain the mechanism of the stl function?
1
vote
1answer
20 views

Are my data values too small for chi-squared for trend? If so what trend test can I do instead?

I'm doing a project about dilated kidneys, these can be arranged into mild, moderate and severe. There are 53 patients in total. I want to see if there is a trend in the severity of dilatation between ...
0
votes
1answer
25 views

Testing Cointegration at level or with first differences?

I have a question regarding testing for cointegration. The situation is a follows: I have two time series that are both stationary at level when I consider "constant and trend". They are otherwise ...
1
vote
1answer
39 views

How to determine trend in rainfall data?

I have annual average rainfall data in mm/day units. I want to see the trend of the rainfall, whether its increasing or decreasing. How to do this. My teacher told to put a linear regression line and ...
7
votes
3answers
214 views

Statistical test for increasing incidence of a rare event

I have following simulated data of 2500 persons regarding the incidence of a rare disease over 20 years ...
2
votes
1answer
36 views

How to detect variable seasonality pattern

We have predicted and actual (daily) data for past 3 years. We use 90 days of data for prediction. Generally our predictions are very accurate, but we receive unusual traffic for few days/weeks ( like ...
1
vote
0answers
21 views

Comparing two data sets for a trend in the data

I have two data sets ( have only access to the statistics of data sets like mean, percentile, count etc but not the data it self). I am interested if I could have a metric which can answer below ...
4
votes
2answers
73 views

Analyze trend given a set of points

Suppose I have a set of N values representing EUR/USD rate... [ 1.10 , 1.20 , 1.25, 1.20, 1.19 ] Which is the simplest way for analyzing if values tend to raise or tend to fall? I'm looking for a ...
1
vote
0answers
25 views

Making a Time-series Stationary: Order of Operations

Following various sources including this post, which is the correct approach to making a time-series stationary? Remove trend Remove seasonality or Remove seasonality with estimated trend ...
1
vote
1answer
53 views

How can a 95% confidence interval not overlap with my trendline forecast?

I used holt winters in excel to forecast 12 moths ahead based on 40 months of historic data. Then I ran a monte carlo simulation to create 1000 scenarios and computed upper and lower bounds to create ...
0
votes
1answer
118 views

How to determine “trendiness” of a time series

I'd like to be able to compare two timeseries as to their level of "trendiness" to determine which trends better. For example, assume two stocks, Google and IBM. Would like to understand approaches to ...
1
vote
3answers
69 views

Interpreting moving average chart

Using 26 years monthly price of coconuts I plotted the 2 period, 3 period and 4 period moving average charts. Every line seems to lie overlapped. What can I infer about the trend from this chart?
1
vote
0answers
32 views

How to data mine google for most popular things out of a set?

Let's say I want to get the list of the top 5000 most searched biomolecules on google - how would I approach such a problem? One possible solution is to fetch the whole pubchem/pdb database and run ...
0
votes
1answer
140 views

How to detect peaks and trends within time series data?

I've been trying to detect defrost cycles using refrigeration data. I have a sensor within the fridge which simulates a product and measures the temperature every 15 minutes. Usually, based on the ...
0
votes
0answers
45 views

Identifying deterministic trend vs stochastic trend

In EViews for Augmented Dickey Fuller Test I get a p value of 0.4326 .I have few questions regarding this? 1.Does this mean I have a stochastic trend or a ...
0
votes
1answer
50 views

Time series Analysis using LS

I know this is a bit of a broad question but generally if I have a time series and I want to measure whether it has trend according to time I do the following: I regress the series against time, ...
2
votes
0answers
37 views

Trend analysis for change in multivariate distribution over time

At each time point, I have a multivariate distribution $x=[x_1,x_2,x_3]$. I don't have that many time points around 3-15. I would like to know whether the change of the distribution over the time is ...
1
vote
0answers
18 views

Temporal Data set

I have a fishery data set of fourteen years in a tropical region. This kind of information is quite rare in ecological studies.The data were monthly collected and the set has 2 annual gaps and a gap ...
3
votes
1answer
93 views

Most accepted theory to analyse trend in data series

I have pollutant concentration for long period I want to determine trend. I have read some of the question answers in this blog regarding same . I have few queries. What is most accepted theory to ...
2
votes
1answer
62 views

Interpreting the result of decomposing time series

I don't have a lot of experience working with time series data. Now I have a 3 year, monthly data for several entities (you can think about them as different stores), that I would like to do some ...
2
votes
1answer
20 views

How to display potential outage when usage fluctuates greatly among customers?

I work for a Health Information Exchange. We have numerous "participants". Some send hundreds of messages a day, some might go a day or two without sending any messages. I'm creating a daily report ...
3
votes
0answers
184 views

chi square for trend - SPSS

I have followed fourth-year university students for ten years, recording their attitudes to a particular lecture. The outcome is binary (good-bad). I have 10 rows and 2 columns, meaning year and ...
2
votes
1answer
87 views

Common trends with Difference in differences

For OLS to have good properties, we should assume that $E(u|X)=0$. When using DiD, is it then this assumption which requires the so-called common trend assumption (need for the DiD to have good ...
0
votes
1answer
29 views

Change detection in trending degradation data

I'm working with degradation data and are trying do use change detection methods to detect repairs. Since I'm looking for repairs I'm only interested in positive changes. Between the repairs the data ...
1
vote
0answers
56 views

Should outliers in a time series be removed before or after detrending?

I am doing a classical time series analysis. When do I remove outliers in the data? After detrend or before detrend?
4
votes
1answer
42 views

Trend Visualization of N time series

I have about 500 time series with different trends, and each time series represents a given nb of transactions. (Volumes follow a long tail distribution). I would like to plot a summary graph on ...
1
vote
0answers
59 views

Dealing with seasonality in time series with no trend

I'm working with quarterly time series data. The series does not have a trend but fluctuates around more or less a constant mean. I observe weak seasonality such that the values are somewhat lower on ...
0
votes
0answers
58 views

Does downsampling affect trend

I have a large set of time series data for which I want to identify the trend. For trend identification I am using a Simple Moving Average (SMA) function over my raw data in order to smooth them ...
2
votes
1answer
24 views

Approach for estimating expected time required (Regression analysis)

I am analyzing data from a factorial experiment with between subject factor Purifier (two types A and ...
0
votes
0answers
83 views

How to determine significant difference between two sets of time series data?

I have 2 sets of time series data. The data were collected from individuals who were matched (via propensity score matching) prior to collection. The only difference is that one set of matched ...
0
votes
0answers
74 views

How to find if there is a trend in a time series and stationarity

I would like to conclude on a given time series that if it has Trend or not. I have carried out a cox-stuart test in R and have decomposed to inspect the series visually but still a bit confused on if ...
0
votes
0answers
19 views

How can I identify if there is a trend?

We need an indicator/model that identify properly the market momentum of a certain array. Ideally we would like to have an indicator that swings from two given value and identify if an array is in ...
0
votes
0answers
7 views

What measures can be applied to the arrival of unique website visitors to asses whether there is an increasing or decreasing trend?

I am looking at the logs of arrivals of unique visitors to a website. I can plot the data as a histogram, and look at the plot to get an idea of whether there is an increasing or decreasing trend in ...
0
votes
1answer
104 views

How to translate percentage decline into a regression slope?

I want to model a negative relationship of count/binary data over 10 years with a known value for the decline rate (in percentage). However, I have problems in calculating the correct slope value for ...
0
votes
0answers
26 views

I am interested in conducting a trend analysis with random subject/item intercepts/slopes, in R

I have a dichotomous outcome variable and am using an IV with three levels. Is it possible to run a trend analysis in which the DV is the likelihood of success, while also including random subject ...
1
vote
1answer
70 views

Is there a rising trend in Number Series

I am trying to build a stock screening utility. What I am trying is to find if there is a rising trend in a time series of profit margins of a company. I know there can be dips in some years but I ...
2
votes
1answer
102 views

Statistically testing for a significant difference between two slope values [closed]

I have five trend lines plotted in excel of number of prescriptions of a 5 different drugs over time (MM/YYYY) and I want to test the statistical significance of the difference between the slopes, to ...
0
votes
0answers
66 views

Detrending or Differencing in order to make a series stationary?

I got several time series for which I want to find out if they are stationary or not. So I computed for each series the kpss.test(). But before making further ...
1
vote
1answer
65 views

The constant term after 1st differencing

My instructor stated that when the dependent variable is 1st differenced, the constant term represents the deterministic change or trend in the dependent variable. When I search for information ...
0
votes
0answers
152 views

determinstic trend in VAR-models

I'm asking myself the following question. I want to build a VAR-Model with 6 time series A, B, C, D, E and F. I analysed every series univariate and I found out that A, D, E and F are stationary and B ...
0
votes
0answers
19 views

How to adjust rank for ad for its recent trend in click-through-rate?

I am building an optimization service for an Adtech company. For ranking ads in terms of performance, I am using formula: Log(impressions)*eCPM. Impressions means the number of times ad was ...