macro
###########################################################################
#
#       Macro: HBINS.MAC
#  Written by: Cathy Akritas     August 2002
#
#  This macro displays the frequency and percent of observations that fall 
#  into the user specified intervals.  You can specify the same intervals 
#  from a histogram to display a table of the interval endpoints and the 
#  frequencies.  
#
#  Suppose the first interval of a histogram of your data in C1 has a 
#  midpoint of 20.5, the last interval of your histogram has a midpoint of 
#  40.5, and the increment between the midpoints is 2.  To run this macro, 
#  choose Edit > Command Line Editor.  Type the command, 
#
#  %HBINS 20.5 40.5 2 C1
#
#  and click on Submit Commands.
#
#  The output in the Session Window will look something like
#
#  Row  Intervals    Frequencies   Percents
#   1  19.5 to 21.5            8   10.6667
#   2  21.5 to 23.5            7    9.3333
#   3  23.5 to 25.5            5    6.6667
#   4  25.5 to 27.5           13   17.3333
#   5  27.5 to 29.5            6    8.0000
#   6  29.5 to 31.5            4    5.3333
#   7  31.5 to 33.5           11   14.6667
#   8  33.5 to 35.5            2    2.6667
#   9  35.5 to 37.5            7    9.3333
#  10  37.5 to 39.5            8   10.6667
#  11  39.5 to 41.5            4    5.3333
#  12  Totals                 75  100.0000
#
#  Suppose you created a histogram where you specified the use of 
#  cutpoints rather than midpoints, and the first interval starts at 20, 
#  the last interval ends at 40 and the width of the intervals is 2.  To 
#  get the table of the frequencies, choose Edit > Command Line Editor.  
#  Type the command
#
#   %HBINS 20 40 2 C1;
#   cutpoint.
#
#  The output in the Session Window will look something like 
#
# Row  Intervals  Frequencies   Percents
#   1   20 to 22           11   14.6667
#   2   22 to 24            5    6.6667
#   3   24 to 26            8   10.6667
#   4   26 to 28           12   16.0000
#   5   28 to 30            3    4.0000
#   6   30 to 32            6    8.0000
#   7   32 to 34            9   12.0000
#   8   34 to 36            5    6.6667
#   9   36 to 38            6    8.0000
#  10   38 to 40           10   13.3333
#  11   Totals             75  100.0000 
#
#  The first argument after the %HBINS is always the smallest 
#  midpoint/cutpoint, the second argument is always the largest 
#  midpoint/cutpoint, the third argument is the increment and the last 
#  argument is the column of data.  
#
#  Just as with MINITAB's histogram algorithm, observations that fall on 
#  interval boundaries are placed into the interval to the right, with one 
#  exception:  observations on the boundary of the interval that is 
#  farthest to the right are placed in the last interval.
#
###########################################################################
#
#  Neither Minitab, Inc. nor the author(s) of this MACRO makes any claim 
#  of or offers any Warranty whatsoever with regard to the accuracy of 
#  this MACRO or its suitability for use.  Minitab, Inc. and the author(s)
#  of this MACRO each hereby disclaims any Warranty and/or liability with 
#  respect thereto. 
#
###########################################################################

hbins lo hi inc x;
cutpoint.
mcolumn x Freqs bins binslo binshi to a Ints Percents
mconstant lo hi inc cnt i j binlo binhi k1 total

mreset
noecho
brief 0
notitle
if cutpoint = 1
  set bins 
    lo:hi/inc
  end
else
  let lo = lo - .5*inc
  let hi = hi + .5*inc
  set bins 
    lo:hi/inc
  end
endif

let cnt = n(bins) - 2

do i = 1:cnt
  let j = i+1
  let binlo=bins(i)
  let binhi=bins(j)
  let Freqs(i) = sum((x ge binlo) and (x < binhi))
enddo
  
let i = cnt + 1
let j = i + 1
let binlo=bins(i)
let binhi=bins(j)
let Freqs(i) = sum((x ge binlo) and (x le binhi))  
let total = sum(freqs)
let Freqs(j) = total
 
copy bins binslo;
omit j.

copy bins binshi;
omit 1.

text binslo binslo
text binshi binshi
tset to
  (" to ")i
end
concat binslo to a
concat a binshi Ints
kkset k1 "Totals"

stack Ints k1 Ints
let Percents = (Freqs*100)/total
name Ints 'Intervals' Freqs 'Frequencies' 
brief 2
print Ints Freqs Percents
endmacro