# Tagged Questions

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

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### How to assign weights to frequency scores based on other frequency scores

I have a question concerning the weighting of frequency scores as I am embarking on a rather unusual procedure: I would like to weight these frequency with other frequency scores. I will try my very ...
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### How to interpret frequency decomposition of a time series?

Consider a time-series $x_t$ at, say, quarterly frequency. I perform a discrete Fourier transform (DFT) $z(f)$ of $x_t$. Then, for each $z(f)$ I perform the inverse transform and get $x_t(f)$, that ...
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### How do I quantify the uniformity of sampling time?

My datasets cover a long time, say 20 years, and the data are sampled at different time. For example, some are obtaiend at 1:00(stored as 100), some are 23:00(2300). If I plot the histogram of the ...
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### Simple frequency question [duplicate]

I have a sample of 100 (N=100). This is binary data (0 and 1); 30 times a 1 and 70 times a 0. I would like to test how often a 1 is existent in the real population. For my sample this is 30% obviously....
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### in SAS: Why are the CI for OR and RR in proc freq more narrow than in a logistic regression for a 2x2 table

I want to estimate risk for a certain outcome. For example age on disease X. I coded dummy variables from ordinal and nominal data (age, gender, etc) to create 2x2 tables. So, I turn my three age ...
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### Estimating minimum sample size for item ranking based on frequencies

Assume that we observe some objects (e.g. people, car models, etc.). Our task is to sort objects based on their frequency of observation. For example, Here is the top 5 best-selling cars in America: ...
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### how to tabulate reference category

i've got a qualitative variable "profession" which can assume 5 different values which are: worker, office worker, teacher, employee management, manager. I choosed worker as the reference category so ...
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### Normalized term frequency comparisons across documents of differing length & language

I aim to infer on the prevalence of terms across and within corpora of different languages (where document length varies within and across corpora). Given Zipf’s and Heap’s laws a simple tf/n seems ...
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### Percentile rank for list of event freqencies.

I have a global list of event frequencies and then another list of local event frequencies for another population of the same type. The objective is to compare the local frequencies with the global ...
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### Can I Use DFT To Find The Most Common Frequency?

I have a collection of data which measures the change in state of a device which records information. I basically record the time a new observation is made on the device. I want to collect the data ...
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### How do I conduct a comparison of two 6x4 frequency tables that hold different data?

I am trying to statistically compare two frequency tables (6x4) of two independent samples (see picture for example of one group's table). What would be the best way to evaluate whether these ...
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### Using frequency tables to judge similarity

I'm a newbie to data mining, and attempting to simplify a problem. Assume I want to find out what skills make up a certain profession. So I'll ask the user to input their profession, followed by a ...
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### what should take frequency for Daily Summarizes Transaction data.

I am little confuse about to take a frequency for time series data on daily transaction data in ts() function. I have 2 years of Daily Transaction data (Means How many amount withdrawal in a day ...
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### Correlation between monthly and quarterly data

Does anybody know how to measure the correlation between monthly and quarterly data? I would like to calculate the correlation between ISM PMI (monthly) and Real GDP growth (quarterly). So, the 2 ...
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### Enrichment of mutations in particular region of the gene

I have a gene say "X" of 3000 base pairs. 300 of those 3000 bp belong to ring domain. Rest 2700 do not belong to ring domain. In a particular tumor, the ring region has 4 alterations and the rest of ...
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### Why do small sample sizes give more significant p-values for rare events?

Maybe I'm getting a bit confused, but I have a single binomial variable with very low frequency (e.g. 1 event in 100,000 trials), and I'm trying to figure out what sample size is required to show a ...
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### How can I use inputs of lower frequencies to predict an output of higher frequency?

I would like to use a NARX or a LSTM to use different type of data at different frequencies -for instance weekly, monthly and quarterly- to predict data sampled at a higher frequency -in my case, ...
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### likert scale analysis

i have 34 types of accounting violations, and i want to know which violations can be considered as a fraud, i asked this question to experts by using likert scale questioner, the answers are strongly ...
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### how to represent MLB games as time series

I have been requested to predict National league(NL) OPS (to start with) for the coming season and compare to a given team predictions to be able to evaluate a chanse of winning a certain number of ...
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### Find high occurring low values

In numerical data, where outlier is defined not by infrequency but value (this is a real-world data-set where low values would be indicative of noise). Although this is real world data, there is no ...
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### inequal amplitudes and opened classes

i have to questions and i need the help of experts 1)In the case of inequal amplitudes, is the sum of the corrected frequencies is equal to unit? 2)In the case where the extreme classes are opened , ...
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### VAR model for variables of different frequencies

I am trying to capture the transmission of monetary policy in India. I am willing to take into account the effect of Non Performing Assets (NPAs) on the transmission from the policy rate to bank ...
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### Estimating the distribution of frequencies from a sampling of unique values

Let $L$ be a list of elements with repetitions, and $S$ be the set of elements appearing in $L$. I have two tools at my disposal: I have a sample of $k$ elements taken uniformly in $S$, and for each ...
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### Why does multiplication in the frequency domain equal convolution in the time domain?

This question came in the context of understanding how to get a distribution of a sum of two iid random variables. I'm working through the top answer to this question Consider the sum of $n$ uniform ...
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### test significance for frequencies

I have frequency data for six datasets (3 control samples and 3 treated samples) consisting of values for physical stiffness, when I plot the frequencies against stiffness it looks like the treated ...
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### Why 'Assumption of Uniformity' for Mean?

I am teaching some very basic statistics for grouped data. In a different class a few years ago I made an 'assumption of uniformity' about the data: within bins, data is uniformly distributed E....
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### How to calculate a mean of a sample where some measurements do not match a normal distribution?

I have a set of temperature measurements from amateur meteo stations around the place I live in. Being amateur meteo stations, the measurements vary because of the placement of the probe, measurement ...
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### Can a value appearing more frequently for a class help predict it?

I am trying to analyse my data before doing multi-class classification with SVM. I have several variables. I pick one of them and study it. This is a categorical variable. It can have the value 0 or ...
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### Frequency of phenotype based on probability of genotypes

I know that in genetics you never know the frequency of any trait, even if you know the probability of having that trait. For example I know that the probability of having A+ blood is = P(AA+/+) + P(...
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I am pretty naive to statistics, so please correct me where I am wrong. I am trying to estimate average case loading factor for travel company. This travel company is running shuttle service wherein ...
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### Hypothesis testing: test difference in frequencies

I have sampled some data, and want to argue that one class of events is more common that another class of events. To get concrete, let's use an example involving text. Suppose I sample some English ...
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### Analysis method for nominal dichotomous data from mixed design

I have the following data set (example): Subject Treatment-group Decision_x Decision_y Decision_z 1 1 A B A 2 1 B B ...
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### Testing for top 3 options

I have data as shown in the chart below. There are 1144 rows of data and for each data row, an event (A, B, C, ..., I) could either have occurred or not occurred (that is, on or off; binary). For ...
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### Expected frequency (per million words)

I'm trying to figure out what this paragraph means: The final measure was (like #2 and #3) designed to exclude discipline-specific and technical words. It states that the word cannot occur ...
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### Calculating expected number of zero-crossings of a white noise process

I am curious about how to calculate the expected number of zero-crossings of a white noise process over some time $t$. In particular I would like to be able to deduce the expected frequency of zero-...
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### Difference between samples in terms of frequency ranks

I have 3 different texts, and for each one of them, I have the frequencies of 25 letters appearing in those texts (Text A, letter A, freq = 5013; Text A, letter B, freq = 1462,...). These texts have ...
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### Finding a representative upper limit of a large dataset

I have summer cumulative solar radiation data derived from a model on an area in North-West Italy. I extracted the modelled values from specific regions (i.e. within rock glaciers outlines), obtaining ...
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### Cramer's V and word frequency

I am investigating the frequency of a word in two distinct corpora. In one corpus, it occurs 232 out of 189,489 times, and in the other corpus it occurs 4394 times out of 559,715 times. The result of ...
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### Log vs. double normalizing of Term Frequency

In the wiki page on Term Frequency-Inverse Document Frequency (tf-idf) there are two interesting TF weights: Double normalization $K$: $K + (1-K)\frac{f_{t,d}}{\max_t f_{t,d}}$. In this question I ...
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### Inference of frequency of values in a poisson distributed histogram

For some data there is a histogram, which has bins with varying sizes. Is it possible to infer the frequency of the values for smaller segments of the bins, favourably with Matlab? With the attached ...
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### Poisson distribution vs Three-way table to Compare multiple incidences

I need some help understanding the difference between comparing incidences of rare events with a Poisson distribution and using a three-way contingency table. I'm sure I have some fundamental ...
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### The frequency in histograms

My question is trivial, but the problem is that I found contradictory answers on internet. So I have the following sample data: ...
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### Normalization of distributions

I am measuring intensities of structures in biological tissues, which gives a series of values for each sample. There is high variability between values for each samples from unknown procedural biases....
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### Assigning weights (or importance) based on frequency

Data I have prepared the data (67 dimensions) in the form of vectors like: 1,0,0,0....66 times 0 (just 1st dimension having ...
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### chi-squared to test if two variables have the same frequency distribution

I want to test if x and y have the same frequency distributions using chi-squared. In my code below, I've concluded that because ...
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### Am I breaking the assumptions of the Poisson distribution?

The Poisson distribution arises when events are counted within a specified interval. I've recorded the number of events each month (I'll not discuss what these events represent). This appears to meet ...
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### Find the values between percentiles in a frequency distribution

In the distribution below, how would I find the values that lies between 30% and 50% of the distribution? R code would be handy but not essential! 28, 28, 29, 30, 30, 31, 31, 31, 31, 32, 32, 32, 34, ...
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### Statistics question related to the Charleston shooting

Note: This will be a long post, and I apologize for that. There's been a lot of parsing of President Obama's words with regards to the "frequency" of shootings in other countries. I contend he's ...