Tagged Questions

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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0answers
8 views

Mean value of normalized histograms with equal bins are the same [on hold]

I a m using normalized histograms (total area is one) for histogram comparison (to check if the distribution is drawn from same population). But the mean is always the same value for all the ...
0
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0answers
16 views

Kullback-Leibler Divergence of 2 histograms: Bin width issue?

I am calculating the distance of 2 histograms using Kullback-Leibler Divergence (KLD). Of course, the number of bins of 2 histograms are the same. However, I have a question about the bin width of the ...
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1answer
26 views

Ways to test bar charts with few bars to see if they come from the same distribution?

I have survey data with ordinal/categorical data. Most of the time the answers to question are Yes/No. I want to compare the bar charts (normalized) of yes/no from participants who gave a particular ...
0
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0answers
21 views

How do I write a function to draw histogram in R? [migrated]

I want to write a function that takes in the variables from a data frame as arguments and prints the corresponding histogram for that variable in R. I have been trying to make use of hist() function ...
1
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1answer
26 views

(Frequency Histogram) - Bins of equal width [duplicate]

How do I create 5 bins of equal width to plot a frequency histogram of the following sequence of numbers? 0.15 0.54 0.23 0.65 0.36 0.15 0.87 0.65 0.90 0.64 0.74 0.98 0.96 0.74 0.82 0.91 0.19 This ...
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0answers
8 views

Difference between two vectors of unequal size

I have a predictive model function mPred and two different input variables matrices of the same size (nxm), iM1 and ...
0
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0answers
53 views

Plotting histogram in R, error on stat=“bin”

I'm trying to plot day against number of migrations as a histogram in R, but I'm coming up with this error message: ...
2
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3answers
96 views

What is “the shortest half of the data”?

Here is a histogram (realized with JMP) displaying two types of box plot called outlier box plot and quantile box plot. Right below, there are a bunch of explanations of the meaning of the ...
0
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0answers
22 views

histograms/ kernel density estimation for proportion data

I am looking at digital advertising data with the following columns: site_id | impressions_count| clicks_count. I am interested in a histogram of the click through rate (clicks/impressions) across ...
0
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0answers
11 views

Histograms With No Final Interval Upper Limit

If you have the following histogram, how do you calculate the mean if you do not know the upper limit of the final interval: ...
2
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2answers
94 views

Optimal bin width for two dimensional histogram

There are lots of rules for selecting an optimal bin width in a 1D histogram (see for example) I'm looking for a rule that applies the selection of optimal equal-bin widths on two-dimensional ...
1
vote
1answer
62 views

Fitting exponential curve to histogram using R

I am trying to fit a curve to a histogram that looks roughly like exponential decay. Since this is roughly similar to exponential decay, I figured a good model was ...
2
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1answer
89 views

Rank histogram (or Talagrand Diagram) of precipitation data

Given a dataset of lines containing 6 wind forecast values plus 1 observed (actual) value in each like: ...
2
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2answers
282 views

Comparing two histograms

I would like to know what are the common techniques to compare two histograms? I have histogram of two images and I want to see are they similar or not meaning that is there any correlation between ...
1
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0answers
17 views

Methods for 3D histograms comparison

When I wish to compare 2D image histograms I can use methods like Chi-Square and Intersection but what are my options if I wish to compare 3D histograms (e.g, based on R,G,B values)? Thanks.
0
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2answers
147 views

Plotting a Gaussian in Python

I am trying to plot a histogram of my data, and I seem to be a little confused here. I am using matplotlib in Python. Here is the code from their website: ...
2
votes
1answer
32 views

How to measure the magnitude of difference between two gaussian distributions? Specifically with rates of DNA mutations

As the title says I want to quantify the difference in the rates of sequence change between genes. When I measure the mutation rates between my subgenomes I can determine a significant but slight ...
1
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0answers
37 views

generate frequency distribution from database

In a MySQL database there's a table with a single numeric value column. I want to plot the distribution of these values as a bar chart/histogram with the following ...
1
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0answers
7 views

Select most different observations

I have a polar chart representing eight dimensional observations as 'rings' around the center. Furthermore, I am limited to Excel for graphing purposes, which means I can only display 255 series at ...
3
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0answers
39 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 ...
0
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1answer
37 views

Quantifying Change in a Histogram Valued Timeseries

I'm attempting to do binary classification where my raw features are collections of histograms that are recorded in a time series. These histograms are scaled to sum to 1. To be more precise and ...
1
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1answer
33 views

Which distribution to parametrize price histogram with exponential tail?

I have plotted price histograms which seem to follow and exponential tail very well. However, I would also like to parametrize the initial peak in the low price range. Can suggest what ...
0
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0answers
42 views

How to corretly scale sum of squared residuals of two different sets of data in order to compare them?

I did numerical simulations of two different systems that returned me N=1000 histograms expressed as $\{x,y,y'\}$, where $x$ is the independent variable, $y=P(x)$ is the probability distribution ...
0
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0answers
52 views

2d histogram or 3d histogram?

Is the following plot a 2d histogram or a 3d histogram? On one hand it has 2 dimensions of data, but on the other, the plot itself is 3 dimensional.
5
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3answers
1k views

My distribution is normal; Kolmogorov-Smirnov test doesn't agree

I have a problem with the normality of some data I have: I've done a Kolmogorov test which says it isn't normal with p=.0000, I don't understand: the skewness of my distribution =-.497, and the ...
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0answers
35 views

BOW prediction of cluster for training data

I am creating a bag of visual words for classification of videos. I am not using SURF descriptors and that is why I couldn't use OpenCV's BOWImgDescriptorExtractor ...
0
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0answers
29 views

Histogram distance metric for extreme values only

I am interested in a histogram comparison method or histogram matching technique that takes into account only the tails of the distribution. Consider the following histograms: Histogram 1: ...
0
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1answer
856 views

Calculating the variance of the histogram of a grayscale image

I am doing image processing and I want to calculate the variance of a histogram of pixel intensities. The first method I have tried: The images store the pixels values using double precision ...
1
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2answers
177 views

Normality tests for histograms

I understand that one quick way to test for normality is to create a histogram from my data and see if it "looks bell-curved". Alternatively, I can use some normality test like Pearson's chi-squared. ...
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0answers
49 views

Outliers in a bimodal distribution

Somewhat related to this post. However my question is a little specific. I have some data from gene expression quantification from single cells using RNA sequencing. I haven't had a look at it but I ...
1
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0answers
127 views

Appropriate test for detecting a signal in normally distributed noise

I am doing some signal processing and I have a histogram which has a bell shape when there is only noise in the signal. (I have been advised that this is to be expected due to the central limit ...
0
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0answers
35 views

peak detection - points / sigma ratio

I would like to ask you (statistics experts) if the following approach is kosher or a nonsense. Problem My EM based detection algorithm ends up (for some data) with a result that looks like attached ...
0
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1answer
105 views

histogram normalised to area 1

i have a histogram with the y-axis showing the proportion in percentage. That makes sense to me but now i have read that histograms can be normalized with the result that the area of the rectangles is ...
0
votes
1answer
161 views

Too big (?) histogram values when using normed histo options in SciPy and matplotlib

I have been trying to create a normed histogram using either SciPy or matplotlib (or anything for Python). When I create my histogram with 'normed' option disabled, it looks like below (this example ...
1
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1answer
38 views

How to test which data match model at best

Description I have 1D data with $N$ normally distributed clusters. I have to find a cluster, which is the worst (differs at most from the normal distribution). My approach I calculate $sq = ...
0
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0answers
72 views

Plotting more than three variables in matlab

I am here to seek opinion on how should i represent my data that i have collected. I am to create a presentation focusing on environment. I was told that a simple bar chart and a line graph is a bad ...
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0answers
403 views

HOG Feature Implementation with SVM in MATLAB

I would like to do classification based on HOG Features using SVM. I understand that HOG features is the combination of all the histograms in every cell (i.e. it becomes one aggregate histogram). ...
0
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0answers
26 views

Analyzing the shape of distribution on a histogram [duplicate]

I have three different histograms which are generated from one sample. In each of the histograms, both variables are the same. Although binwidths for each histogram is different. By looking at each of ...
4
votes
2answers
170 views

Is there a better way than side-by-side barplots to compare binned data from different series

I have a number histogram from a data source. I want to compare their distribution. For example series 2 is more to the right than series 1. Is there any good way to contrast besides plotting the ...
0
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1answer
149 views

Normalize histogram with different bin width?

I know how to normalize histogram (so that the area =1) with the same bin width, but how to do it when the histogram has different bin width? Any idea?
0
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0answers
23 views

Compute mean from discrete normally distributed data [duplicate]

I am looking for an estimator of the mean of normally distributed data (with known variance) in the regime where the sampling grid is much coarser than the variance. I.e. in the worst case consider ...
1
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0answers
44 views

Compare Frequencies

I have a continuous predictor variable that I have divided into bins (at 0%, 0 to 25%, ...). For each of these bins, I have shown you the histogram below of Number of Companies that are in that range ...
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vote
1answer
57 views

Frequency Distribution Test Vs. Chi Square Goodness of FIt

I need to prove that the higher frequency of an occurrence within a particular range is statistically significant. Let me explain this with an example: X-axis has ages and Y-axis has the ...
0
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0answers
154 views

Mutual information with outliers

I am using Mutual Information on a data set with some outliers. The univariate variables don't have a known distribution, so I cannot remove them automatically with any neat method, like Grubbs or ...
1
vote
1answer
219 views

Normally distributed errors - Why not use the observed residual histogram?

In the context of the classical linear regression model (with all standard assumptions), we know that when the error term is normally distributed, least squares is minimum variance among all linear ...
2
votes
0answers
461 views

How to get Bhattacharyya Distance in Excel (or Matlab, or R)

I have several histograms which I would like to compare to one reference histogram to see which one is the most similar to the reference in terms of the shape of the distribution. Kologorov-Smirnov ...
5
votes
0answers
102 views

Is this a normal distribution?

I have done some processing to my original data. Before the processing I had a nice histogram with a bell shape. Now it still looks like a bell shape to me if I would slice off the first half and ...
1
vote
1answer
389 views

How do I correctly produce a prior/posterior plot from MCMC chains in Bayesian hierarchical models?

I'm a beginner at hierarchical modeling and statistics in general and this is confusing me. Question: If I draw a histogram of a posterior distribution from an MCMC chain, do I draw the prior as a ...
0
votes
0answers
29 views

Quantify agreement of histograms filled with autocorrelated data

I'm having an issue quantifying the agreement/disagreement of histograms that were filled with autocorrelated data. The context: I'm working with gps-data on velocities, that were recorded with 1Hz. ...
2
votes
1answer
101 views

Kernel density estimation - application

What is the validity of using a kernel-density-estimation to compare model x observed data? In other words, if the KDE curve for the observed data looks like the KDE for the model forecast, can I use ...