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Questions tagged [boxplot]

A graphical display to summarize the distribution of a sample. It displays five numbers plus (possibly) some outliers - those five points being the median, hinges (approximate quartiles), and the largest and smallest value not counting any points marked as outliers.

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33
votes
2answers
9k views

Is there a boxplot variant for Poisson distributed data?

I'd like to know if there is a boxplot variant adapted to Poisson distributed data (or possibly other distributions)? With a Gaussian distribution, whiskers placed at L = Q1 - 1.5 IQR and U = Q3 + 1....
7
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2answers
3k views

How to use boxplots to find the point where values are more likely to come from different conditions?

I have plotted some data using box plots. I am comparing Condition 1 (left) and Condition 2 (Right) values. My aim is to find a point at which we make a decision where the value changes from point ...
3
votes
1answer
27k views

Boxplot interpretation: is it correct that a boxplot is missing a whisker?

I have a data set that has customerID and daily visits. This dataset records the number of times customers visited the site in a day. ...
25
votes
6answers
8k views

What are good data visualization techniques to compare distributions?

I am writing my PhD thesis and I've realized that I rely excessively in box plots in order to compare distributions. Which other alternatives do you like for achieving this task? I'd also like to ask ...
13
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2answers
12k views

Box-and-Whisker Plot for Multimodal Distribution

Can I use box-and-whisker plots also for multimodal distribution or only for unimodal distribution?
9
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3answers
3k views

Boxplot for several distributions?

I need to draw 20 distributions in a single graph in R, and it doesn't look good (cluttered) to me with regular boxplot (20 boxes) even with boxwex=0.3. Could you suggest me how can I plot a kind of ...
8
votes
2answers
7k views

How to interpret a box plot?

I have some data in which there are 5 categorical explanatory variables (concern, breath, weath, sleep, act) and 1 continuous response variable (...
17
votes
3answers
15k views

How to present box plot with an extreme outlier?

I could use some guidance about presenting some data. This first plot is a case-control comparison for the cytokine IL-10. I've manually set the y axis to include 99% of the data. The reason I set ...
7
votes
2answers
12k views

Why does Tableau's Box/Whisker plot show outliers automatically and how can I get rid of it?

I have a data set shown as box-whisker graphs after disaggregating. See below. I am wondering why Tableau (the product I am using) automatically plots a whole bunch of values outside the box-whisker. ...
10
votes
1answer
698 views

Box plot notches vs. Tukey-Kramer interval

The "notch" help document (or original text) from boxplot in 'R' gives the following: If the notches of two plots do not overlap this is ‘strong evidence’ that the two medians differ (Chambers et ...
19
votes
3answers
93k views

How to assess skewness from a boxplot?

How to decide skewness by looking at a boxplot built from this data: 340, 300, 520, 340, 320, 290, 260, 330 One book says, "If the lower quartile is farther from the median than the upper quartile, ...
8
votes
1answer
4k views

T-test using only summary data in a box plot

I have the 5 number summary (min, Q1, Median, Q3, max) from two boxplots and wanted to test whether or not the averages of the groups in the two boxplots were significantly different. I would like ...
6
votes
3answers
4k views

Is it appropriate to identify and remove outliers because they cause problems?

This all pertains to my Psychology honours thesis. I have two groups (Autism and control) and all participants completed four tasks. It is very important to my study that the groups do not differ on ...
19
votes
7answers
20k views

What are some alternatives to a boxplot?

I am working on creating a website, which displays the census data for a user selected Polygons & would like to graphically show the distribution of various parameters (one graph per parameter). ...
8
votes
1answer
9k views

Highlighting significant results from non-parametric multiple comparisons on boxplots

I have box plots of 13 groups that I show in one plot. The groups have unbalanced populations and are not normally distributed. I want to show which pairs are statistically similar (i.e., have kruskal....
9
votes
2answers
410 views

Understanding the whiskers of a boxplot

I have a question regarding the interpretation of the whiskers of a boxplot. I have read the following: "On the top and bottom of the rectangle, the “whiskers” show the range of 1.5 times the distance ...
19
votes
1answer
789 views

What's the history of box plots, and how did the “box and whiskers” design evolve?

Many sources date the classic "box plot" design to John Tukey and his "schematic plot" of 1970. The design seems to have stayed relatively static since then, with Edward Tufte's cut-down version of ...
13
votes
2answers
25k views

“When to use boxplot and when barplot” rules (of thumb?)

Both box-and-whisker plot and bar chart are appropriate graphics for ANOVA according to The R Book (Crawley, 2013), but which is more appropriate? I suppose it depends on situation... can anybody help ...
5
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3answers
1k views

Is visual inspection the only way to compare large datasets?

I have two large data sets, in fact, one of them is even much larger than the other. Visually, there doesn't seem to be that much difference between them: The actual data underlying the box plot ...
13
votes
4answers
22k views

What information does a Box Plot provide that a Histogram does not?

Histograms give a good sense of the distribution of a variable. Box plots attempt to do the same thing however, don't give as good of a picture of the distribution of this variable. I don't ...
8
votes
7answers
13k views

Plotting confidence interval bars from summary statistics

A bit like a box plot. I mean not necessarily the standard upper confidence interval, lower confidence interval, mean, and data range-showing box plots, but I mean like a box plot with just the three ...
1
vote
1answer
1k views

How to draw a side-by-side plot mentioned in “Graphical Display as an Aid to Analysis”

Emerson, J. D. (1991) Graphical Display as an Aid to Analysis, in Fundamentals of Exploratory Analysis of Variance (eds D. C. Hoaglin, F. Mosteller and J. W. Tukey), John Wiley & Sons, Inc., ...
17
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4answers
2k views

What is the basis for the Box and Whisker Plot definition of an outlier?

The standard definition of an outlier for a Box and Whisker plot is points outside of the range $\left\{Q1-1.5IQR,Q3+1.5IQR\right\}$, where $IQR= Q3-Q1$ and $Q1$ is the first quartile and $Q3$ is the ...
11
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2answers
9k views

Reading box-and-whisker plots: possible to glean significant differences between groups?

Suppose we're looking at this box-and-whisker plot: Between Thursday and Friday, I think most would agree there seems to be a significant difference in time slept. Is that a statistically-valid ...
11
votes
2answers
7k views

Wondering what this bean plot analysis chart means

How does one interpret and generate bean plot charts. Here is one example taken from Walkes et al. 2010. What kind of data is it most useful for? (source: biomedcentral.com)
10
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1answer
425 views

Visualizing many left-skewed distributions

I have a series of left-skewed/heavy tailed distributions that I would like to show. There are 42 distributions across three factors (labeled as A, ...
2
votes
1answer
6k views

ANOVA - Homogeneous variance, what to look for in a boxplot

I'm just starting out learning about ANOVA, I'm having trouble understanding how to check for homogeneous variance assumptions. One source I have seems to be looking at box-plots, and another looks at ...
1
vote
1answer
133 views

Help needed with my box plot

I decided to give box and whiskers plots a try with my data. However, the produced box plots look a bit abnormal. I have not been able to find such cases online. For example, my "T" value has no box ...
1
vote
1answer
147 views

boxplot in R shows wrong outliers

Can someone explain why does boxplot in R show me outliers when they are actually not? I have a dataset for computer sales and I have to predict the price based ...
0
votes
1answer
156 views

How can this boxplot be transformed suitably?

In R, I have produced a boxplot for two different groups, with discrete y-values between 1 and 20. My goal from this work is to investigate whether the average count differs between A and B: ...
11
votes
1answer
7k views

What is a 'bagplot', or 'bivariate boxplot'?

I've found a paper which introduces the multidimensional (bivariate here) version of the boxplot - a bagplot. What is that bagplot exactly? I can see the series of nested polygons based on vertices, ...
7
votes
3answers
470 views

What distribution can be closely (or precisely) fit to the “5 number summary” statistics?

I'm programming a web tool (="I'm a stats ignoramous who drifted here from stackoverflow.com") that allows scientists to enter predictions about the 5-number-summary stats for a variable. Entry is ...
5
votes
1answer
596 views

How to transform an accuracy distribution for a violin plot

I am trying to find the best way to visualize different distributions of accuracy. Accuracy here is a value in the interval [0,1], 0 meaning not accurate, 1 maximum accuracy. I have different methods ...
4
votes
1answer
8k views

Negative inner fence. How can you find the outlier using 1.5 x IQR?

I'm trying to find outliers using 1.5 x interquartile range but I'm getting a negative value for the lower bound. I found Q3 and Q1 which are 13.30 & 3.00 respectively but for the lower bound i ...
3
votes
2answers
351 views

Comparing weights versus time graphically using reshape, vioplot, and ggplot2

I have a group of 200 children who came to clinic at months 0, 1, 2, 3, 6, 9, and 12 this year. At each clinic visit the children were weighed. ...
2
votes
2answers
5k views

statsmodels: error in kde on a list of repeated values

I am using Python's statsmodels module to plot a violin/bean plot of some data. I get the error "LinAlgError: singular matrix" in the KDE calculation whenever a single violin plot is drawn from a list ...
1
vote
1answer
390 views

Testing the difference between two samples with very different sizes using an un-paired t-test

I want to test wether population A is significantly different from population B (at 5% confidence interval). I need to do it for each variable using an un-paired t-test, since my data are normally ...
1
vote
3answers
200 views

Alternative to boxplots that illustrate MEAN

What is a good alternative to boxplots that reflects the MEAN and STANDARD ERROR , not the median and its quartiles ? A package in R that does that would help a lot.