Questions tagged [histogram]

A histogram is a graphical representation of the frequencies of a continuous variable. The variable is divided into bins and a bar is drawn for each bin, proportional to its frequency in the data.

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Bhattacharyya distance for three histograms

There is a paper “Auto White Balance Based on the Similarity of Chromaticity Histograms” mention about automatic white balance. One of the key point of this algorithm is how to measure the similarity ...
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Where is the maximum bias and variance in a histogram as non-parametric density estimator?

I am a little bit confused about bias and variance of non-parametric density estimators and hope you can help me. Assuming a constant bandwidth and sample size, I am wondering at which points of the ...
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Linear mixed effects models: what to do when the residual QQ-plot looks non-normal?

I have four linear mixed effect models of similar structure: ...
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33 views

What methods are there for estimating distributions based on histograms?

I recently worked on a consulting project where a client wanted to estimate gamma and weibull distributions based purely on histograms rather than raw-data. I have never worked with problems like that ...
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121 views

How to compute optimal binning for two histograms

I am plotting two histograms on top of one another (using matplotlib, but that is tangential to my question). My current approach is to compute the mean of the optimal bin widths for each histogram ...
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98 views

Is it sensible to calculate posterior by dividing histograms?

I have some data I want to classify as $A$ or $\bar{A}$ (not-$A$) based on two metric features $M$ and $P$. It seems straight-forward to calculate a posterior probability, that a given combination of $...
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239 views

Make 2D color histogram with uniform distribution (Likert scale)

UPDATE: I've been told that I cannot specifically ask for help in regards to the programming (MatLab and PR Tools), but instead should seek help for general techniques. So that's what I'm doing. Long ...
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101 views

clustering for histogram shapes

I am trying to get a start on a clustering problem. The sample data is trade volume at a particular price. Some notes about the data: number of bins vary from sample to sample (larger price range ...
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42 views

10% dip in February for metrics that count?

February usually has 28 days, unlike it's neighbors January and March which have 31. It seems that most countable things will exhibit, on average, a 10% dip in February for the missing 3 days. This ...
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2k views

Combining errors in a histogram (binned data)

I'm processing some data that requires binning before it goes through a regression algorithm. The script is in Python and uses the Numpy histogram function, but ...
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31 views

A comparison of the global optimal binwidth and local optimal binwidth of the histogram estimator

Suppose we have $X_1, \dots, X_n$ to be an i.i.d sample with unknown pdf $f(x)$ and cdf $F(x)$, and define $\hat{f} (x)$ to be the histogram estimator. We also define its Mean Integrated Square Error ...
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25 views

Can I draw a histogram of the mean sample distribution (n=30) sampling from my dataset (n=200)?

I would like to test whether my data reasonably satisfies the normality assumption necessary to apply a t-test. My understanding is that, to apply a t-test, the distribution itself does not need to ...
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95 views

How to aggregate histograms for density estimation

Within a very large sensor network, each node does take measurements derived from a fixed number of samples taken at a high frequency from an instrument. The number of measurements send to an ...
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237 views

What is the correct way to modify the bin-counts given a threshold for a chi-squared test?

When performing a chi-square test, one inputs the expected counts (via integrating probability distribution over respective bin bounds) and observed counts into the chi-square formula (denoted below). ...
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1answer
451 views

How to evaluate a histogram?

Let's say I have the histogram above which reports performances of some neural networks. The y axis is the bin size, while the x axis is the error, so low errors = high performance. Out of these 15 ...
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359 views

Differential histogram bin calculation

I want to be able to minimize a difference between two distributions $P(x|\theta)$ and $Q$. I can choose Q (e.g. to be a Gaussian normal), but $P(x|\theta)$ is an unknown distribution, so I am ...
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79 views

Displaying distributions of data with a high number of features

I have data of two different groups. From each data, I have say 100 samples, each sample having 20 features. I want to display the distribution of each of the two datasets. Now I have some very ...
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Given the number of Bins, what is the formula for estimating bin height in a 2D Histogram

Given the number of Bins, what is the formula for estimating bin height in a 2D Histogram in binormal distribution?
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134 views

Combining histograms from different experiments

Roughly speaking (i.e., hopefully I don't need to contextualise too much), I ran an experiment five times to find the length of some aluminum sheet. Using a Bayesian model I got five different looking ...
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55 views

Low Probability Estimate from Cumulative Frequency Histogram

I've fitted a 3-parameter Weibull distribution into a sample size of $N=31392$ using Maximum Likelihood Estimation. I'm comparing exceedance probability estimates with the data's cumulative frequency ...
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46 views

Evaluation of a group of histograms

I'm trying to learn statistics on my own and currently taking an online class through edX. Unfortunately some things are not clearly explained. The online book used for this class contains the ...
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115 views

Error on histogram computed on autocorrelated time series

I am struggling to find an answer to this quite basic question. When computing a histogram on a time series which has some correlations (i.e. measurements are not independant), how to estimate the ...
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623 views

Knuth rule for number of bins of a histogram vs. chi2 fitting

I try to make a histogram and then fit some distribution to it by means of chi2. The Knuth rule (I have some bimodal cases so I'm not using Freedman-Diaconis or Scott) gives me the following histogram ...
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385 views

How to pick a good threshold for multimodal histograms

I am trying to do multi-modal detection in a vote map (histogram) however, side lobes obviously cause some false peaks. So using mean shift will not do as it will find all of the local maxima. So I ...
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482 views

On the uniform convergence of relative frequencies of events to their probabilities

I have read the article by Vapnik, Chervonenkis "On the uniform convergence of relative frequencies of events to their probabilities" Theory of Probability and Its Applications, vol XVI, n. , 1971. ...
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274 views

Establishing a dynamic threshold for partitioning data

Given a sorted set of data points, where each point represents the length of a common substring between two files, I want to systematically decide a cut off point where I can start considering them to ...
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30 views

What is the best way of presenting many Bar Chart plots

I used R programming to produce separate 30 Bar Chart plots. The x-axis scale is the same for the 30 plots (11 bins), but y-axis is different. I want to present these results in a limited work of ...
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105 views

How to plot a marginal histogram correctly? Why is my plot different to the one in a textbook?

Chapter 1 of "Machine Learning - A Probabilistic Perspective" by Kevin Patrick Murphy gives this figure (fig_1), and says this is a pairwise scatter plot on iris dataset. The diagonal plots the ...
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43 views

How to compare 2 2-D histograms and get the probability of the 2 being the same / having samples drawn from the same/very similar distributions?

I was looking at this post describing methods of comparing histograms and in particular bin-to-bin comparison and cross-bin comparison and want to know how to use these to numerically evaluate how ...
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1answer
110 views

downsampling a kde / combining kde and histogram

I'm calculating a KDE of one parameter (y, particle density) in bins of another parameter (x, distance from the origin). At ...
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15 views

Constructing an appropriate null hypothesis?

I have a collection of 20 2D surfaces embedded in 3D. The mean curvature of each surface has been sampled. The number of samples per surface varies from ~700,000 to ~20,000,000. The choice of ...
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563 views

K-Nearest-Neighbor classification with only distance/similarity matrices, is it possible?

I want to classify histograms/distributions using K-Nearest-Neighbor. I can measure distances/dissimilarities between the distributions (using euclidean distance, kullback-leibler divergence...), thus ...
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Why do we subtract the $cdf_{min}$ in this step of histogram equalisation?

In my question I am referring to histogram equalisation as it is described in the wikipedia article in this example here. Given an grey image $I$ of size $M \times N$, in histogram equalisation one ...
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24 views

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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288 views

95% confidence interval error bars of normalized histogram

I have observational data from a satellite and I am studying a certain phenomenon. I have locational data of these phenomena (let's call this data set A). I have divided the data into histogram bins ...
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27 views

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 ...
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124 views

How to divide the data to analyze [Histograms in R]

I am working on the data of a contest, of 85 days duration, where all the participants could choose to participate or not every day. The distribution seen through a histogram is: [Histogram with the ...
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678 views

Why do these two logarithmic binning methods give different results? (in R)

Problem I am working on a problem involving logarithmic binning. I have a dataset consisting of individuals that have a size value and a production value. I am using an algorithm to logarithmically ...
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How to produce a normalized cumulative histogram?

I am having trouble understanding the proper method to calculate specific histograms, specifically with regard to cumulative and normalized histograms. If I want to calculate a normalized cumulative ...
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123 views

How do I estimate the ERROR for a histogram?

I am sampling a random variable from a system so as to find the underlying distribution. To do so, I can plot either a histogram, or a kernel density estimate. Either way, how do I indicate the ...
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40 views

Assess whether the generated data follows the distribution

Using the Inverse function method I managed to draw a sample of 500 random data from a Cumulative distribution function. $f(x)$,$F(x)$ and $F_X^{-1}(u)$ are as follows: $$f_X=\frac{x}{5}exp\left({\...
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Numerical method to compress empirical probability distribution

I am trying to grapple with the following problem. I have an application that develops empirical distributions. In essence, I end up with a histogram of equally spaced $x$ values, with both a $max$...
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256 views

Derivation/Explanation of the Freedman-Diaconis Rule

Can anyone provide a good derivation of the FD rule? Or explain why it is a good way to define the bin widths of a histogram. Are there any other similar rules and how do they compare?
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IRT vs proportion/frequency

Lets say I have response data from a multiple choice exam question and I want to understand whether the item was too difficult, or if I should change it somehow to improve it What benefits do I get ...
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283 views

How to fit a truncated distribution to binned data?

I have the age at deaths data in the form of intervals ie 0-4, 5-9, 10-14, ... 80 & above years.I have converted inclusive class intervals to exclusive class intervals ie age: 0-4.5, 4.5-9.5, 9.5-...
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How are various rules for determining frequency distribution binwidth derived?

I've been looking up the problem of deciding appropriate binwidths for histograms and here's my broad-level understanding so far: If we have $n$ data points, we assume that they're realizations of $n$...
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324 views

Rebinning histogram for goodness-of-fit test: p-hacking?

I need to fit a 7-parameter function (actually 6 since one of them is fixed) on a histogram using ROOT. The function is basically an asymetric gaussian curve. The algorithm I'm using actually makes ...
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144 views

Visualizing ACS PUMS data with weight / PWGTP

I am working with American Census PUMS microdata, a yearly sample that includes a total weight per record and 80 replicate weights. I'm unsure if it makes sense to do descriptive statistics such as ...
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677 views

Programmatically calculate which bin a value will fall into for a histogram

I'm trying to programmatically create a histogram. The number of bins is specified by the user. My issue in this problem is that I came up with what I thought was a reasonable way to determine which ...
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Does the y-axis of a histogram have to be frequency?

The definition of a histogram is a graph in which the x-axis is a quantitative variable split into bins, and the y-axis is the frequency. However, if we want to graph some other property of the bins (...