- Function File:
`s`=**boxplot***(*`data`,`notched`,`symbol`,`vertical`,`maxwhisker`, …) - Function File:
*[…*`h`]=**boxplot***(…)* -
Produce a box plot.

The box plot is a graphical display that simultaneously describes several important features of a data set, such as center, spread, departure from symmetry, and identification of observations that lie unusually far from the bulk of the data.

`data`is a matrix with one column for each data set, or data is a cell vector with one cell for each data set.`notched`= 1 produces a notched-box plot. Notches represent a robust estimate of the uncertainty about the median.`notched`= 0 (default) produces a rectangular box plot.`notched`in (0,1) produces a notch of the specified depth. notched values outside (0,1) are amusing if not exactly practical.`symbol`sets the symbol for the outlier values, default symbol for points that lie outside 3 times the interquartile range is ’o’, default symbol for points between 1.5 and 3 times the interquartile range is ’+’.`symbol`= ’.’ points between 1.5 and 3 times the IQR is marked with ’.’ and points outside 3 times IQR with ’o’.`symbol`= [’x’,’*’] points between 1.5 and 3 times the IQR is marked with ’x’ and points outside 3 times IQR with ’*’.`vertical`= 0 makes the boxes horizontal, by default`vertical`= 1.`maxwhisker`defines the length of the whiskers as a function of the IQR (default = 1.5). If`maxwhisker`= 0 then`boxplot`

displays all data values outside the box using the plotting symbol for points that lie outside 3 times the IQR.Supplemental arguments are concatenated and passed to plot.

The returned matrix

`s`has one column for each data set as follows:1 Minimum 2 1st quartile 3 2nd quartile (median) 4 3rd quartile 5 Maximum 6 Lower confidence limit for median 7 Upper confidence limit for median The returned structure

`h`has hanldes to the plot elements, allowing customization of the visualization using set/get functions.Example

title ("Grade 3 heights"); axis ([0,3]); tics ("x", 1:2, {"girls"; "boys"}); boxplot ({randn(10,1)*5+140, randn(13,1)*8+135});

The following code

axis ([0,3]); boxplot ({randn(10,1)*5+140, randn(13,1)*8+135}); set(gca (), "xtick", [1 2], "xticklabel", {"girls", "boys"}) title ("Grade 3 heights");

Produces the following figure

Figure 1 |
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Package: statistics