Questions tagged [frequency]

The frequency measures the number of times an event occurs in a data set.

Filter by
Sorted by
Tagged with
-1
votes
0answers
7 views
0
votes
0answers
17 views

Comparing frequency distributions of two samples

Consider the following two samples (numbers are put here for illustration): \begin{array}{|c|c|c|c|} \hline & males & females& other \\ \hline \textrm{Sample 1} & 100 & 150 &...
1
vote
1answer
36 views

Hypothesis testing for apriori market basket analysis

I'm wondering if there is a possibility to perform hypothesis tests to show that the resulting rules from an apriori market basket analysis are statistically significant? Maybe I'm missing the forest ...
1
vote
1answer
20 views

Compare frequency counts between two groups with 300 observances(variables)

I have a dataset with observations of counts (I've also calculated proportions of the total) between two groups. These observations are essentially on the presence of material types. I'm trying to ...
0
votes
0answers
7 views

Compare frequencies for nominal values between two groups

I collected two sets of usability problems during a user study and an inspection done by experts. Each problem was assigned to a category. I want to find out if there are significant differences in ...
0
votes
0answers
7 views

Locating and characterising changes in event frequency over time

I have simple time-series data which consists of just one kind of time-stamped event. I'd like to understand when and how the frequency changes. In particular, with regard to one very obvious change ...
1
vote
2answers
59 views

Zero Frequency and Small Sample Size

I have a situation where the skeletons from one of three archaeological sites do not display a bone condition called periostitis that is found at the other two. The relevant statistics are: ...
1
vote
0answers
31 views

Specification on power spectral density for population data

What is the best way to put a specification on the single-side auto-power spectral density (PSD)? We have a product for which we have a time signal. For this signal we calculate the PSD (or ...
0
votes
1answer
31 views

Why does TF-IDF use the count of the most common word in the document instead of total count of all words in the document?

From what I understand, the "term frequency" ("TF" in TF-IDF) is calculated from the number of times a certain term occurs in a document vs the most common term in a document: ...
0
votes
0answers
41 views

Extracting the right summary statistics from zero-inflated data sets (i.e. a sparse matrix where everything non-zero is a statistical outlier)

I'm a consumer tech startup founder with rudimentary background in statistics. I need help in processing a large, sparse matrix. I'm logging all actions users are undertaking in my app. I then ...
2
votes
1answer
58 views

Methods for analyzing “cross-frequency” tables?

I am looking for a statistical method that is suitable for the problem: which goods in my shop are most frequently bought together, and which aren’t? For my commodities, I can make a table like this ...
14
votes
3answers
2k views

How to measure the statistical “distance” between two frequency distributions?

I am undertaking a data analysis project which involves investigating website usage times over the course of the year. What I would like to do is compare how "consistent" the usage patterns are, say, ...
3
votes
6answers
341 views

How do I find the mean of counts of reported events when the last category is “5 or more”

I know that we can find mean (No. of errors per patient) from 0*5+1*30+2*56+3*15+4*10 But for 5 or more, what do I need to do?
1
vote
0answers
15 views

Cepstrum: quefrency scale to frequency scale

Can someone please explain to me how to convert a quefrency scale to the corresponding freqncy? For example consider this: A voice signal is measured at 50kHz sampling frequency and FFT power ...
0
votes
1answer
26 views

Comparing the distribution

I want to compare the distribution of 2 independant datasets. Measurements were performed on an experimental dataset (TEST) and compared with a completely independant reference dataset (REF). The idea ...
0
votes
1answer
20 views

How to compare frequencies among groups?

I want to compare the frequency of a categorical value among 4 groups, what statistical test should I use? (I am using SPSS). I am looking for a statistical test that would allow me to say: the ...
0
votes
1answer
57 views

Are theoretical probability and relative frequency comparable?

Speaking of probability measure (a number from 0 to 1), textbooks usually describe several interpretations of this number. E.g., Practical Business Statistics by Andrew F. Siegel reads (p. 132): ...
0
votes
1answer
24 views

Measure like relative frequency that also weights the total [closed]

Background I see a lot of publications mentioning relative frequencies to indicate the presence of certain genes in a specific area. For example: ...
0
votes
0answers
12 views

Analyzing Accelerometer and Gyroscope Data on a Drone

I am using an MPU-6050 Gyroscope and Accelerometer for a drone flight controller. I have been able to get raw data from the sensor, and account for bias and use the included Digital Low pass Filter at ...
3
votes
0answers
24 views

Granger causality tests when series are measured at different frequencies

As a research exercise I should perform Granger causality tests on pairs of national series (one describing output gap and the other an index of consumers' confidence). However, I face a situation ...
0
votes
0answers
18 views

Estimate frequency based on given sample

I have a list of users (~25 million) and a dataset containing events created by the users in a specific time window (eg all tweets of all Twitter users that happened in a month - on avg I have 100K ...
0
votes
1answer
17 views

Testing an intervention by repeated measure of opinion before and after the intervention

How can we test the null hypothesis that an intervention has no effect on opinions for 44 people. These opinions were measured as frequencies in 3 categories (A, B, C) before and after the ...
0
votes
1answer
100 views

How to choose the frequency value without know the seasonality of the data in R ts() package

I am trying to analyze the S$P 500 data on Kaggle. I have a daily values of the opening stock prices. As frequency is the number of observations taken in a cycle, I am guessing I need to know the ...
0
votes
0answers
96 views

change in frequency of time series data

I am working on a survey data which is quarterly from 2008 to 2014 and it becomes bi-monthly 2014 onwards. Can someone please suggest how to tackle this data? It is not possible to interpolate due to ...
0
votes
0answers
56 views

Preprocessing of time series data to spectral analysis

If we want to find the periodicities of a time series, we can use spectral analysis. We can plot the the periodogram and find the major component, then we can find the major periods. But to do this, ...
0
votes
1answer
18 views

How to test normalized frequencies

I have extracted the frequency of two words (can, may) from two corpora (Corpus1, Corpus2). I want to test if there is a significant difference between the counts in the two corpora, but since the ...
1
vote
0answers
32 views

Statistical analysis for quasi-experiments

This is my first message on this forum. I hope I am not doing any mistake. I must analyze data obtained after a quasi-experiment and I am not sure how to proceed. The experiment has been carried out ...
0
votes
1answer
37 views

Which statistical test should be used for several samples frequency distributions?

I have the frequency distribution of muscle fiber size from several control and several problem animals and I'd like to compare both groups, but all the statistical tests I know for frequency ...
0
votes
0answers
26 views

How to do an equidistribution test? [duplicate]

Suppose I have a sample of $N$ numbers $a_1,\dots,a_N$ from $1,\dots,k$. How can I test whether they are equidistributed? I'm not interested in a full randomness test as the order does not matter to ...
2
votes
1answer
424 views

What time-series frequency should I use? Weekly, monthly, quarterly

First, I read the Q&As here, but it's not entirely clear for me what to do given my situation. I have more than 1700 different time series, each expressed as weekly data. My objective is to ...
1
vote
0answers
44 views

Should I use weekly or daily returns for modelling FX returns?

I am currently modelling Foreingn Exchange returns using a GARCH model. I am simulating returns 1-year forward. Would it be better to use weekly or daily data on Foreign Exchange returns? Weekly data ...
1
vote
1answer
18 views

How can I use the distribution of run lengths to test if a sequence is generated from flips of a fair coin?

I have a very long sequence (in the tens of thousands) of binary outcomes from some data-generating process. I believe that these outcomes are iid Bernoulli trials with p = 0.5, equivalent to flipping ...
0
votes
0answers
28 views

Class frequency comparison (exponential distribution)

I have two different sources of data and I would like to check if their class distributions are similar and how much. The first dataset ($D_1$) has 2M samples and the second ($D_2$) 6M. When I ...
0
votes
0answers
34 views

Can VAR models capture all frequency interactions reliably and to the same extent?

I would like to assess how a set of ~50-100 time-series variables causally interact with each other. To do this, I am fitting a VAR model and using cross-validation to estimate model-order. After the ...
1
vote
1answer
50 views

Specifying frequency parameter in the absence of occurrences

Let's say I have a process where the occurrences are independent, proportional to time. I made $n$ observations for which I only observed no occurrences. My goal is to define a frequency parameter and ...
0
votes
1answer
56 views

Regression with frequency rating in percent as dv

I seem to have a similar issue as asked in this thread, nevertheless I'm still clueless about what model I have to fit to my data. I conducted a repeated measure experiment (consisting of 2 sessions) ...
0
votes
1answer
47 views

Count frequency distribution of monomial

If you sample $N$ times from a set of $n$ objects with replacement and then plot the frequency against the count (i.e. the number of times an object has been chosen once, twice,...), you get a ...
0
votes
1answer
12 views

Find out which characteristics to choose, based on the frequency measurement of characteristics of similar items

I have this statistics oriented question and I need some input on the approach. There is a new product introduced, a contact lence that has seleral ranges of attributes (powers) from which the users ...
0
votes
1answer
82 views

What is the correct distribution? [closed]

Let, I have the following Frequency Distribution: Which one would be the correct Grouped frequency Table if class-width = $1.0$? $Table\#1$ $Table\#2$ Explain "Why". What would be the answer if $\...
0
votes
1answer
19 views

Calculating effect sizes when a certain proportion of subjects give one of four answers

How can an effect size be calculated between two groups when the data is reported in frequency proportions (e.g., each group has people who have answered a question about relationships with either: ...
0
votes
1answer
51 views

Expected vs observed frequency of two events at the same time

I'll first give an example and afterwards a more formal definition of my problem. Example: Let's assume I'm looking at balls with two properties: their color can be black or white, their weight ...
0
votes
1answer
371 views

What is the difference of frequency and probability of occurrence?

I'm reading lots of statistical anomaly detection articles nowadays. Some of them use frequency of some feature for detecting anomalies on the new trace. But, something gets my attention in some ...
4
votes
2answers
229 views

Is it possible to obtain more accurate annual extremes predictions from sub-annual data?

I'm looking at various extreme climate variables, such as 50-year or 500-year maximum daily precipitation, using a generalized extreme value (GEV) distribution. The problem with this is that there are ...
3
votes
3answers
115 views

Distribution of *conditional* frequencies when frequencies follow a Dirichlet distribution

Context: we have a large number of individuals characterized by two binary traits; call these $T$ with values $\{0,1\}$, and $T'$ with values $\{0',1'\}$. So there are four types of individuals: $00'$,...
1
vote
0answers
33 views

Fisher's exact test with opposite direction of categories for two groups

I would like to analyze student performance under two teaching approaches for two classes. We predict that class 1 would outperform class 2 and ideally the performance between two classes should be ...
1
vote
0answers
38 views

How to analyze the frequency of correct/ non-correct answers

I have a question about how to analyze some data. It involves the performance of two equally sized groups in a questionary with 30 arithmetic questions that I scored with two possible outcomes (...
0
votes
1answer
14 views

Statistical test for comparing two frequencies with R [duplicate]

i have this situation. A set of 5000 objects, 4950 blue and 50 green. From this set two people (person A and person B) fish separately 100 objects each and i would like to know if one of the two ...
2
votes
2answers
84 views

What kind of frequency distribution is this?

I have a discrete frequency distribution, that looks like this I am trying to find what type of distribution is it? I looked at many models but it does not seem to comply with any. I have 345 ...
1
vote
0answers
38 views

calculating sample size needed for a target confidence interval from categorical data

So I will have data sorted into one of five bins (flow cytometry sorting of cells). These bins are actually adjacent categories that quantify a single fluorscence level (0-20,20-40,40-60,60-80,80-100)....
0
votes
1answer
55 views

How to approach cipher decoding using frequency analysis

so I'm working on a project where I'm trying to decipher an input text using frequency analysis. So far I've added first letter frequencies, common bigrams, double letter frequencies, as well as ...