Statistical Analysis Stack Exchange
Statistical Analysis Stack Exchange

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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Assessing approximate distribution of data based on a histogram

Suppose I want to see whether my data is exponential based on a histogram (i.e. skewed to the right). Depending on how I group or bin the data, I can get wildly different histograms. One set of histograms will make is seem that the data is…
guestoeijreor
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Calculating optimal number of bins in a histogram

I'm interested in finding as optimal of a method as I can for determining how many bins I should use in a histogram. My data should range from 30 to 350 objects at most, and in particular I'm trying to apply thresholding (like Otsu's method) where…
Tony Stark
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R - QQPlot: how to see whether data are normally distributed

I have plotted this after I did a Shapiro-Wilk normality test. The test showed that it is likely that the population is normally distributed. However, how to see this "behaviour" on this plot? UPDATE A simple histogram of the data: UPDATE The…
Le Max
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How to assess the similarity of two histograms?

Given two histograms, how do we assess whether they are similar or not? Is it sufficient to simply look at the two histograms? The simple one to one mapping has the problem that if a histogram is slightly different and slightly shifted then we'll…
Mew 3.4
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How is Poisson distribution different to normal distribution?

I have generated a vector which has a Poisson distribution, as follows: x = rpois(1000,10) If I make a histogram using hist(x), the distribution looks like a the familiar bell-shaped normal distribution. However, a the Kolmogorov-Smirnoff test…
luciano
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How to test if my distribution is multimodal?

When I plot a histogram of my data, it has two peaks: Does that mean a potential multi-modal distribution? I ran the dip.test in R (library(diptest)), and the output is: D = 0.0275, p-value = 0.7913 I can conclude that my data have a…
user1260391
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Benefits of using QQ-plots over histograms

In this comment, Nick Cox wrote: Binning into classes is an ancient method. While histograms can be useful, modern statistical software makes it easy as well as advisable to fit distributions to the raw data. Binning just throws away detail that is…
MvG
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Comparing two histograms using Chi-Square distance

I want to compare two images of faces. I calculated their LBP-histograms. So now I need to compare these two histograms and get something that will tell how much these histograms are equal (0 - 100%). There are many ways of solving this task, but…
Anton Holovin
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Goodness of fit for 2D histograms

I have two sets of data representing stars parameters: an observed one and a modeled one. With these sets I create what is called a two-color-diagram (TCD). A sample can be seen here: A being the observed data and B the data extracted from the…
Gabriel
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Difference between histogram and pdf?

If we want to visibly see the distribution of a continuous data, which one among histogram and pdf should be used? What are the differences, not formula wise, between histogram and pdf?
user1102
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How the Pearson's Chi Squared Test works

Following a recent down vote I have been trying to check my understanding of the Pearson Chi Squared test. I usually use the chi squared statistic (or reduced chi squared statistic) for fitting or checking the resulting fit. In this case the…
Bowler
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Could any equation have predicted the results of this simulation?

Suppose there is a coin that has a 5% chance of landing on HEADS and a 95% chance of landing on TAILS. Based on a computer simulation, I want to find out the following : The average number of flips before observing HEADS, TAILS, HEADS (note: not…
stats_noob
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QQ plot does not match histogram

I have a histogram, kernel density and a fitted normal distribution of financial log returns, which are transformed into losses (signs are changed), and a normal QQ plot of these data: The QQ plot shows clearly that the tails are not fitted…
Stat Tistician
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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 kurtosis =-0,024 Here is the plot of my distribution…
Boo
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Need help identifying a distribution by its histogram

I have the sample population of a certain signal's registered amplitude maxima. Population is about 15 million samples. I produced a histogram of the population, but cannot guess the distribution with such a histogram. EDIT1: File with raw sample…
mbaitoff
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