similar to: boxplots

Another naive stats question. I'm trying to better understand what boxplots are telling me. I think what I see is the median and the boundaries of the 1st and 3rd quartiles. The whiskers represent the range of the data unless there are points which are outside "range" (default: 1.5) times the distance from the median to that quartile. Is that right? I've read the

Hi, I have a simple question about quartiles in R, especially how they are calculated using the boxplot. Quartiles (.25 and .75) in boxplot are different from the summary function and also don't match with the 9 types in the quantile function. See attachment for details. Can you give me the details on how the boxplot function does calculate these values? Cheers, Rene Brinkhuis

I have read and reread the boxplot and the boxplot stats page, and I still cannot understand how and what boxplot shows. I realize that this might be due to me not knowing enough statistics, but anyway... First, how does boxplot determine the size of the box? And is the line inside the box the mean or the median (or something completely different?) And how does it determine how long out the

Hello, I faced something I can't understand. When I use boxplot.stats(1:10) and quantiles(1:10) the results are different for 25% and 75%: > boxplot.stats(1:10) $stats [1] 1.0 3.0 5.5 8.0 10.0 > quantile(1:10) 0% 25% 50% 75% 100% 1.00 3.25 5.50 7.75 10.00 Actually, I expected the value 3 for 25% and 8 for 75% as results of quantile(1:10). Can you please explain me

For boxplot(), is it possible to pass in a parameter to change the default way that the 1st and 3rd quartiles are computed? (specifically, I'd like to use type 6 described in the quantile function). Also, what are the options for how outliers are computed, and how can one change them? Thank you [[alternative HTML version deleted]]

How are the lower/upper whiskers defined in the default version of boxplot {graphics}? I tried help(boxplot) and searching www.rseek.org, but I was unable to determine an absolute answer. I checked out the definition of boxplot according to Wikipedia (http://en.wikipedia.org/wiki/Box_plot), but it also had several approaches listed for how the whiskers could be determined, so I'm just

Dear list, How can I add the mean and standard deviation to each of the boxplots using the example provided in the boxplot function? boxplot(len ~ dose, data = ToothGrowth, boxwex = 0.25, at = 1:3 - 0.2, subset = supp == "VC", col = "yellow", main = "Guinea Pigs' Tooth Growth", xlab = "Vitamin C dose mg",

I've just started using R and am still a neophyte, but I found the following curious result. I'm using the current version of R (2.5.1 (2007-06-27) ). Why are the results for the third quartile different in the output from the summary and fivenum commands? For the following data set 457 514 530 530 538 560 687 745 745 778 786 790 792

I really like the ease of use with the boxplot command in R. I would rather have a boxplot that shows the average value and the standard deviation then the median value and the quartiles. Is there a way to do this? Chad Junkermeier, Graduate Student Dept. of Physics West Virginia University PO Box 6315 210 Hodges Hall Morgantown WV 26506-6315 phone: (304) 293-3442 ext. 1430 fax: (304)

In a Box and Whisker plot, I thought that when there are outliers both abov= e and below the whiskers, then the whiskers should both be the same length = (plus or minus 1.5 times the inter-quartile range). If you look at the plot for SilwoodWeather on p.155 of The R Book you will = see that for November (month =3D 11) the upper whisker is shorter than the = lower, while for other months with

The standard R boxplot appears to use quartiles to determine the height of the rectangles and a range parameter - RNG - (default=1.5 I think) that determines the length of the whiskers as <= RNG x Interquartile Range. Is it possible to instead define the range as extending to the 95th percentile? If so, how would this be done? nb, I'm plotting multiple boxplots on a single chart so a

Any help with this problem would be greatly appreciated: I need to produce a custom plot i haven't come across in R. Basically, I want to show means, 1st standard deviation and 5th and 95th percentiles visually, using something resembling a boxplot. Is it possible to completely customize a boxplot so that it shows means as the bar (instead of, not as well as medians), standard deviations at

Hello, I have a couple more questions about boxplots. In the books I've read on statistics (I'm not a statistics expert but just a poor engineer trying to help his wife with the analysis of the data she gathered for her medieval history PhD), I seen two kinds of box plots: one using quartiles to determine the height of the rectangles and whiskers which is what the standard R boxplot does,

Hello: I am plotting some data using the box and whisker plot. However, I only want to plot the median, max and min, as I only have these values and not the quartile values. It seems R arbitrarily constructs the box margins to be halfway between the median and the max/min. How do I make the box and whisker plots without the box values? Thanks, Michael [[alternative HTML version

Hi List, Just wondering where the documentation exists for the statistics which makeup the bwplot. I'm guessing that if R is like similar products that the graph is constructed as The median is the filled circle. The box surrounding the filled circle depicts the 25th and 75th quartile. The range of values is given by the dotted lines (?whiskers?) outside of each box, and possible

I am trying to draw a plot like Matlab does: The upper extreme whisker represents 95% of the data; The upper hinge represents 75% of the data; The median represents 50% of the data; The lower hinge represents 25% of the data; The lower extreme whisker represents 5% of the data. It looks like: --- 95% | | ------- 75% | | |-----| 50% | | | | -------

Dear r-help, Unfortunately I cannot find in the documentation what determines ranges of a 'box' in the box-and-whisker plot. It is said in "Simple R" (http://www.math.csi.cuny.edu/Statistics/R/simpleR) that they are 1st and 3rd Qus usually. I tried to add to boxplot lines with (quantile(x,probs=0.25)), but lines do not coincide with edges of boxes.

Hi, I have data that looks like this: ASA1 ASA2 C1_C2 C M 9.0225 S S 2.4315 M C 3.4894 M S 4.5282 C M 1.3183 C S 1.3735 S C 1.0488 S M 7.948 M C 4.5827 I need to plot Boxplots for a given ASA1 (either C,S, or M) with respect to C1_C2. However, instead of one boxplot I want to plot

Good Afternoon- I was wanting to alter the boxplot to remove the lower whisker, both the whisker line and staple just on the lower end. Is there a way to do this? As my code is currently: boxplot(log_loads~ind,data=nfmaum, horizontal=TRUE, notch=T, outline=FALSE, whisker=0, main="Maumee River Near Future Climate Scenarios", ylab="Log Load",xlab="Climate Scenarios")

Dear list, I am using a external program that outputs Q1, Q3, median, upper and lower whisker values for various datasets simultaneously in a tab delimited format. After importing this text file into R, I would like to plot a boxplot using these given values and not the original series of data points, i.e. not using something like boxplot(mydata). Is there an easy way for doing this? If I am not