Questions tagged [frequency]
The frequency measures the number of times an event occurs in a data set.
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Odds of pulling same word in card game? [on hold]
A friend and I were playing a card game where you have a hand of letters, trying to make word(s) out of those letters. On the first round we both spelled the same word within only one turn each of ...
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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 to determine ...
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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:
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Convert the frequencies of a list elements (table) to data frame in R [migrated]
I have a list like this:
x = c(0,0,1,1,2,3,1,0,4,5,6,4,3,2,1,1,0,2,3)
and I need to create a dataframe with frequencies, where col names are the unique elements ...
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How does one interpret an element of the “transfer matrix” used to calculate frequency domain granger causality (via VAR models)? [migrated]
I am attempting to gain a better mathematical understanding for how autoregressive models can be used to infer frequency-domain granger causality. All freq. domain measures of causality that utilize ...
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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 ...
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1answer
55 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 ...
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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, ...
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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?
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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 ...
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23 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 ...
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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 ...
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39 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):
...
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1answer
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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:
...
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11 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 ...
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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 ...
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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 ...
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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 ...
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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 ...
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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 ...
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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, ...
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1answer
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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 ...
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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 ...
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1answer
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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 ...
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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 ...
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1answer
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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 ...
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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 ...
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1answer
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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 ...
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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 ...
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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 ...
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1answer
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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 ...
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analyzing hierarchically grouped (selection) frequency data
I have a question regarding analyzing hierarchically grouped selection frequency data. (Disclaimer: I have never analyzed this type of data before. I did not think through the data analysis procedure (...
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1answer
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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) ...
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1answer
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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 ...
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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 ...
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1answer
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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 $\...
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1answer
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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: ...
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1answer
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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 ...
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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 ...
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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 ...
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3answers
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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: $00'$,...
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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 ...
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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 (...
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1answer
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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 ...
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2answers
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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 ...
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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)....
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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 ...
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1answer
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Why is “using counts of a frequency table as data” for a histogram a “mistake”?
The textbook, The Practice of Statistics, states the following as a "common mistake" when making histograms:
Don't use counts (in a frequency table) or percents (in a relative frequency table) as ...
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Relative frequency question
I am a new user here, and I need some help getting started with the following question:
The textbook answers are a. $19$ and b. $20$. How do I begin this question? I am a beginner in statistics. :)
...
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How to analyze size frequency data from over 70 sites
When I started my PhD, I had virtually no prep-time. My advisor needed me in the field and told me to go grab samples. As such, my planning wasn't the best, so sorry if this is a completely terrible ...
