How to compute an histogram (plot bars) binning the values from a .csv using TeX?

Question

I've a .csv with a column of acquired measures. I would like to make the histogram bins using TeX from the measures distribution so I have to create the bins first. I haven't found any reference to perform an automatic binning or to set manually the intervals to produce the bins. I would like to know how can I do that and if I can perform non-uniform bins histogram.

\documentclass[border=5mm]{standalone}
\usepackage{filecontents}
\usepackage{pgfplots, pgfplotstable}

\begin{filecontents}{data.csv}
dist
1
2
2.5
2
1
3.5
3
1
3
2
1
1
0.5
1
1.5
1
\end{filecontents}

\begin{document}
\begin{tikzpicture} \begin{axis}
\addplot[xbar] table [
        col sep=comma,
        x=dist
    ] {data.csv};
\end{axis}
\end{tikzpicture}
\begin{tikzpicture}
\begin{axis}
\addplot [ybar interval] table [
        col sep=comma,
        y=dist
    ] {data.csv};
\end{axis}
\end{tikzpicture}
\end{document}

I perform this usually in python (code below) this should be the output:

import matplotlib.pyplot as plt
dist=[1, 2, 2.5, 2, 1, 3.5, 3, 1, 3, 2, 1, 1, 0.5, 1, 1.5, 1]
plt.hist(dist,7) #Compute the histogram of a set of data.

Answer 1

You can use the PGFPlots statistics library for this:

\documentclass[border=5mm]{standalone}
\usepackage{filecontents}
\usepackage{pgfplots, pgfplotstable}
\usepgfplotslibrary{statistics}

\begin{filecontents}{data.csv}
dist
1
2
2.5
2
1
3.5
3
1
3
2
1
1
0.5
1
1.5
1
\end{filecontents}

\begin{document}
\begin{tikzpicture}
\begin{axis}[
    ybar,
    ymin=0
]
\addplot +[
    hist={
        bins=7,
        data min=0.5,
        data max=4
    }   
] table [y index=0] {data.csv};
\end{axis}
\end{tikzpicture}
\end{document}

Answer 2

Here, have some gnuplot. Using the gnuplottex package, typeset using pdflatex --shell-escape:

Code

\documentclass{standalone}
\usepackage{gnuplottex}
\usepackage{filecontents}
\begin{filecontents}{data.csv}
1
2
2.5
2
1
3.5
3
1
3
2
1
1
0.5
1
1.5
1
\end{filecontents}
\begin{document}
\begin{gnuplot}[terminal=cairolatex,terminaloptions={pdf color}]
    set xrange [0:4]
    set yrange [0:8]
    set style fill solid 1
    plot 'data.csv' using 1:(1) smooth frequency with boxes title 'Data'
\end{gnuplot}
\end{document}

Output

Answer 3

Here is a solution using pst-plot:

\documentclass{article}

\usepackage{pst-plot}

\savedata{\data}[{{0.5,1},{1,7},{1.5,1},{2,3},{2.5,1},{3,2},{3.5,1}}]

\begin{document}

\psset{xunit = 2}
\begin{pspicture}(-0.23,-0.53)(4,7.5)
\listplot[
  plotstyle = bar,
  barwidth = 0.8,
  linecolor = red,
  fillstyle = solid,
  fillcolor = blue!70
]{\data}
\psaxes[
  Dx = 0.5,
  xticksize = -4pt 0
]{->}(4,7.5)
\end{pspicture}

\end{document}

P.S. I can't figure out exactly what the data are, but from your plot I've guessed. If I'm wrong, you should be able to change it yourself.

Answer 4

Although is not a pure LaTeX approarch, may be an alternative to someone could be a Sweave (.Rnw) file, that R can convert in a true .tex file.

With a well configured LaTeX editor as TeXworks, or RStudio this is not extra work for the user, as you simply edit the .Rnw file an the PDF file is compiled with one click, without dealing with R nor intermediate LaTeX files.

With this approach is easy make non-uniform bins histograms (with option breaks in the R plot) and set the x-axis range (option xlim):

\documentclass{article}
\begin{document}
\SweaveOpts{concordance=TRUE}

Automatic breaks with range fixed:

<<examplea,echo=F,fig=T,height=3>>=
sample <- read.table("data.csv", header=TRUE, sep="", na.strings="NA", dec=".", strip.white=TRUE)
hist(sample$X1, xlim=c(0,4), main="",xlab="", ylab="", col="orange")

@

Manual uneven breaks:

<<exampleb,echo=F,fig=T,height=3>>=
hist(sample$X1, breaks=c(0.5,1,1.5,3.5),freq=T, main="",xlab="", ylab="", col="cyan")
@

Automatic fixed breaks at these values:

<<examplec,echo=F,fig=T,height=3>>=
mybreaks <- as.vector(exp(seq(log(.01),log(6),by=0.5)))
mybreaks
hist(sample$X1, breaks=mybreaks, freq=T,main="",xlab="", ylab="", col="red")
@

\end{document}