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....
25
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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 ...
20
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7answers
21k 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). ...
19
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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, ...
19
votes
1answer
832 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 ...
17
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3answers
16k 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 ...
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 ...
15
votes
2answers
19k views

Show average instead of median in boxplot [closed]

When plotting a boxplot with python matplotblib, the lines halfway the plot is the median of the distribution. Is there a possibility to instead have the line at the average. Or to plot it next to it ...
14
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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 ...
13
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4answers
23k 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 ...
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?
13
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2answers
156k views

Boxplot with respect to two factors using ggplot2 in R

I am very new to R and to any packages in R. I looked at the ggplot2 documentation but could not find this. I want a box plot of variable boxthis with respect to ...
13
votes
1answer
864 views

What kind of chart is this?

Sorry for the vague question but this chart appears in Biddle et al. 2009 and I've not encountered anything like it before. It's a bar chart with beveled edges, sometimes 'horns'. What do these mean? ...
12
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3answers
28k views

Deduce variance from boxplot

I was wondering how to deduce the variance of a variable using a boxplot. Is it at least possible to deduce if two variables have the same variance observing their boxplot?
11
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4answers
44k views

Labeling boxplots in R

I need to build a boxplot without any axes and add it to the current plot (ROC curve), but I need to add more text information to the boxplot: the labels for min and max. Current line of code is below ...
11
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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, ...
11
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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)
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 ...
10
votes
2answers
27k views

Plotting summary statistics with mean, sd, min and max?

I am from an economics background and usually in the discipline the summary statistics of the variables are reported in a table. However, I wish to plot them. I could modify a box plot to allow it to ...
10
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1answer
4k views

Why is the 95% CI for the median supposed to be $±1.57*IQR/\sqrt{N}$?

In various sources (see e.g. here), the following formula is given for confidence interval for median (especially for the purpose of drawing notches on box-and-whisker plots): $$ 95\%\ CI_{\rm median}...
10
votes
1answer
742 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 ...
10
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1answer
444 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, ...
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 ...
9
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4answers
1k views

Why doesn't the fact that 1 median is lower than another median, mean that most in group 1 are less than most in group 2?

I believed that the boxplots below could be interpreted as "most men are faster than most women" (in this dataset), primarily because the median men's time was lower than the median women's time. But ...
9
votes
2answers
425 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 ...
9
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....
8
votes
7answers
14k 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 ...
8
votes
2answers
8k 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 (...
8
votes
2answers
344 views

Boxplots as tables

We are preparing a manuscript and the editor asked us to convert a figure with a boxplot into a table "because of the more exact data content". While I think boxplots are pretty decent in revealing ...
8
votes
1answer
957 views

box plot in R: Do the outliers count when the quantiles are being determined?

I have a 1 dimensional dataset and I use the boxplot function to make a box plot. Then I can see that I have some outliers. Do the outliers count when the ...
8
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2answers
10k views

R: Box-plot on log scale vs. log-transforming *then* creating box-plot: Don't get same result

In the boxplot() function in R, there exists the log = argument for specifying whether or not an axis should be on the log scale....
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 ...
7
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4answers
12k views

Confused by location of fences in box-whisker plots

In one type of box-whisker plot, the fences at the ends of the whiskers are meant to indicate cutoff values beyond which any point would be considered an outlier. The standard definitions I've found ...
7
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2answers
586 views

Missing quartile in boxplot

Currently I am creating a box plot. I am new on the field of statistics and especially box plots. Find the picture following: On the y-axis find the number of messages. I have problems understanding ...
7
votes
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 ...
7
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3answers
26k views

How to add horizontal lines to ggplot2 boxplot?

I have a boxplot output in R using ggplot2: ...
7
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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. ...
7
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2answers
2k views

Making boxplots of hourly data in R

I have air temperature measurements from two fixed locations measured at hourly intervals. The code below is a random set of numbers used to represent the format of my data: ...
7
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3answers
474 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 ...
7
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1answer
75k views

How to increase size of label fonts in barplot

I have the following R code for creating barplot: ...
6
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2answers
6k views

Interpreting weird box plot with reversed whiskers

Although I'm fairly new to box plots, I thought I had got the hang of them, until I came upon this one today. I don't know what to make of that bottom "whisker" drawn inside the box. This population ...
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 ...
6
votes
1answer
2k views

Understanding and Interpreting letter value boxplots

I have read through the R documentation of lvplots, but it didn't provide enough material on how I would interpret these plots. I want to just have an intuitive ...
6
votes
1answer
3k views

Plotting binomial proportions on a box & whiskers plot using R

Apologies in advance - I'm a bit of a newbie with R but I've been Google-ing this for weeks and I haven't found a straight answer. The problem Basically, I'm looking to plot proportions with their ...
6
votes
1answer
3k views

Violin plot or bean plot? What are the advantages of each?

I would like to represent my data in the most informative way. As successors of the boxplot, I have found violin plots as well as beanplots. What are the advantages of each plot? A violin plot could ...
6
votes
1answer
2k views

Pairwise comparisons for a regression with sandwich estimates (in R)

The question in short I run a regression in R and made a boxplot of the response variable with grouping by one of the predictor variables. On this boxplot I'd like to add some information about the ...
5
votes
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 ...
5
votes
3answers
12k views

How can I draw a boxplot without boxes in R?

Using R, I'd like to plot two boxplots without the boxes—just the points. Creating clean boxplots in R is trivial: ...
5
votes
3answers
2k views

Making box plots when analyzing a case with 3 predictor variables?

When there are 3 predictor variables to consider, what is the correct procedure? Do we make box plots for all the possible 2 combinations or is there a way to compare 3 variables? Sorry if this is a ...
5
votes
1answer
12k views

Negative inner fence value in a box and whiskers plot?

I calculated a negative lower inner fence value. I've double checked my work but I can't figure out what's wrong. I was under the impression that these values couldn't be outside of the min and max (...