I have the following data which I tried to draw
the probability density plot.
Here is the code I have:
x <- read.table("mydat.txt");
d <- rep(x$V2,times=x$V3);
hist(d,probability=T, xlab="FlowSignal");
But why the y-axis range from 0 to 6,
instead of 0 to 1? What's the correct way to plot it?
#id flowsignal frequency
1 0.67 1
1 0.70 1
1 0.75 1
1 0.78 2
1 0.79 1
1 0.83 1
1 0.84 3
1 0.85 3
1 0.86 1
1 0.88 1
1 0.89 1
1 0.91 1
1 0.93 1
1 0.94 1
1 0.96 2
1 0.98 4
1 0.99 2
1 1.00 2
1 1.01 1
1 1.02 5
1 1.04 3
1 1.05 5
1 1.06 5
1 1.07 4
1 1.08 7
1 1.09 6
1 1.10 2
1 1.11 2
1 1.14 1
1 1.15 1
1 1.17 1
1 1.20 1
1 1.21 1
#end of data
Regard,
G.V.
Hi that is a question which comes almost so often as "why R does not think that my numbers are equal". So even I, non statistician, can deduct that hist with probability =T can have any y axis range but the sum below curve has to be below 1. Regards Petr r-help-bounces at r-project.org napsal dne 02.09.2009 06:16:37:> I have the following data which I tried to draw > the probability density plot. > > Here is the code I have: > > x <- read.table("mydat.txt"); > d <- rep(x$V2,times=x$V3); > hist(d,probability=T, xlab="FlowSignal"); > > But why the y-axis range from 0 to 6, > instead of 0 to 1? What's the correct way to plot it? > > > #id flowsignal frequency > 1 0.67 1 > 1 0.70 1 > 1 0.75 1 > 1 0.78 2 > 1 0.79 1 > 1 0.83 1 > 1 0.84 3 > 1 0.85 3 > 1 0.86 1 > 1 0.88 1 > 1 0.89 1 > 1 0.91 1 > 1 0.93 1 > 1 0.94 1 > 1 0.96 2 > 1 0.98 4 > 1 0.99 2 > 1 1.00 2 > 1 1.01 1 > 1 1.02 5 > 1 1.04 3 > 1 1.05 5 > 1 1.06 5 > 1 1.07 4 > 1 1.08 7 > 1 1.09 6 > 1 1.10 2 > 1 1.11 2 > 1 1.14 1 > 1 1.15 1 > 1 1.17 1 > 1 1.20 1 > 1 1.21 1 > #end of data > > > Regard, > G.V. > > ______________________________________________ > R-help at r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guidehttp://www.R-project.org/posting-guide.html> and provide commented, minimal, self-contained, reproducible code.
Your data ranges from 0.67 to 1.21, just to simplify things let's assume the that the histogram will go from the pretty numbers of 0.65 to 1.25 for a total width of 0.6. Now consider the simplest histogram consisting of 1 single bar going from 0.65 to 1.25 (very uninteresting histogram, but good for this example). The probability=T argument means that the total area of the histogram (1 rectangle for this simple case) must be equal to 1. If you can explain to us how to create a rectangle with width = 0.6 and area =1 and a height that is between 0 and 1, then we will be happy to explain the rest of your question (though I expect that trying to answer the above will answer your question for you). -- Gregory (Greg) L. Snow Ph.D. Statistical Data Center Intermountain Healthcare greg.snow at imail.org 801.408.8111> -----Original Message----- > From: r-help-bounces at r-project.org [mailto:r-help-bounces at r- > project.org] On Behalf Of Gundala Viswanath > Sent: Tuesday, September 01, 2009 10:17 PM > To: r-help at stat.math.ethz.ch > Subject: [R] Normalized Y-axis for Histogram Density Plot > > I have the following data which I tried to draw > the probability density plot. > > Here is the code I have: > > x <- read.table("mydat.txt"); > d <- rep(x$V2,times=x$V3); > hist(d,probability=T, xlab="FlowSignal"); > > But why the y-axis range from 0 to 6, > instead of 0 to 1? What's the correct way to plot it? > > > #id flowsignal frequency > 1 0.67 1 > 1 0.70 1 > 1 0.75 1 > 1 0.78 2 > 1 0.79 1 > 1 0.83 1 > 1 0.84 3 > 1 0.85 3 > 1 0.86 1 > 1 0.88 1 > 1 0.89 1 > 1 0.91 1 > 1 0.93 1 > 1 0.94 1 > 1 0.96 2 > 1 0.98 4 > 1 0.99 2 > 1 1.00 2 > 1 1.01 1 > 1 1.02 5 > 1 1.04 3 > 1 1.05 5 > 1 1.06 5 > 1 1.07 4 > 1 1.08 7 > 1 1.09 6 > 1 1.10 2 > 1 1.11 2 > 1 1.14 1 > 1 1.15 1 > 1 1.17 1 > 1 1.20 1 > 1 1.21 1 > #end of data > > > Regard, > G.V. > > ______________________________________________ > R-help at r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide http://www.R-project.org/posting- > guide.html > and provide commented, minimal, self-contained, reproducible code.