It is a little more complicated to obtain plots of two histograms on
the same scale, because it depends on the device you are using to
print.  At home this is rather easy, and I am including instructions
for doing this. In the PC Lab, you'll have to ask the SAS help desk
what device you use and how to set yourself up for printing this graph.


BASIC ANALYSIS OF THE NHANES DATA: WITHOUT PROC CAPABILITY (nhanshrt.sas)
-----------------------------------------------------------

(1) I placed the data on my PC in the directory c:\sas
(2) I called the data hanes.dat
(3) I used windows95 to open SAS. This put the cursor in the
    program editor.
(4) I typed the basic input data:
    options ls = 72;
    data nhanes1;
    input treatmen satfat;
    lsatfat = log(1+satfat);
    cards;
(5) In the menu on top, I clicked on the "open" icon, two icons
    to the right of the running little man.
(6) At the top of the resulting box, it asks me for a place to "look in".
    Since my data are in c:\sas\datasets, I clicked until I got there.
(7) At the bottom, it asks for a "file name". It originally has the
    contents "*.sas", which I deleted and replaced by hanes.dat.
(8) I then finished by clicking on the "open" bar.  This updates my
    program by adding the data in.
(9) I then saved everything by going to "file", hitting the "save as"
    key, and naming the program nhanes.  This is thus saved as 
    c:\sas\nhanshrt.sas.
(10) From now on, I can makes changes to nhanes.sas and then save them
     by hitting the floppy disk icon. 
(11) Now I add to my program. Scroll to the end of the data, and type
     on a new line
proc sort; by treatmen;                  

proc univariate plot;
var satfat lsatfat;
by treatmen;

run;


(12) You now have a complete initial analysis of the NHANES data.
(13) What I do is get out of SAS, then reenter it, go to the program
     editor window, click on "file", click on "open", open
     nhanshrt.sas, and then click on the running little man.
     The output file will open and I can click on print to print
     the output.




BASIC ANALYSIS OF THE NHANES DATA: WITH PROC CAPABILITY (nhanrun.sas)
-----------------------------------------------------------

(1) I placed the data on my PC in the directory c:\sas
(2) I called the data hanes.dat
(3) I used windows95 to open SAS. This put the cursor in the
    program editor.
(4) I typed the basic input data:
    data nhanes1;
    input treatmen satfat;
    lsatfat = log(1+satfat);
    cards;
(5) In the menu on top, I clicked on the "open" icon, two icons
    to the right of the running little man.
(6) At the top of the resulting box, it asks me for a place to "look in".
    Since my data are in c:\sas\datasets, I clicked until I got there.
(7) At the bottom, it asks for a "file name". It originally has the
    contents "*.sas", which I deleted and replaced by hanes.dat.
(8) I then finished by clicking on the "open" bar.  This updates my
    program by adding the data in.
(9) I then saved everything by going to "file", hitting the "save as"
    key, and naming the program nhanes.  This is thus saved as 
    c:\sas\nhanshrt.sas.
(10) From now on, I can makes changes to nhanes.sas and then save them
     by hitting the floppy disk icon. 
(11) Now I add to my program. Scroll to the end of the data, and type
     on a new line
proc sort; by treatmen;                  

proc capability graphics;                
comphistogram satfat / class = treatmen;
title NHANES Data (1=disease);

proc capability graphics;
comphistogram lsatfat / class = treatmen;
title NHANES Data (1=disease);

proc univariate plot;
var satfat lsatfat;
by treatmen;

run;


(12) Save this again by hitting the floppy disk icon.
(13) Hit the little running man to run the program.  A graphics window
     will open up. At the bottom it says "Press forward to see next
     graph". Click on the black down arrow key at the top of the screen
     and the next graph will show up, etc.
(14) You should have an output window. Click on the printer to print
     your results.
(15) To get the pretty comparative histograms, do the following steps:
     (a) Click on "Window" at the top and scroll down to "graph..."
         and release the mouse key.
     (b) Use the black arrow keys at the top to scroll between pretty graphs.
     (c) Everytime you see one you like, click on the printer icon.
         It asks you something about device. Click on help, and scroll 
         to "Printer" and click on it. Then slect your printer from the
         menu, click on that and then select "OK".  Do this for each
         pretty plot you want.  My printer by the way is hpjl100, a laser
         jet series 2 printing 100 dpi.
(16) You now have a complete initial analysis of the NHANES data.

Here is the program that ran all these analyses. If you have a
problem like this in homework, just rename all the variables
and use any editor you want to replace the data.  Then when you get
into sas, go to "file", then "open" and open the file which has
all the data and the program, and run the little running man icon. 


***************************************************************************
            Initial Data Analysis of NHANES Data

            With comparative histograms
***************************************************************************
options ls = 72;
data nhanes1;
input treatmen satfat;
lsatfat = log(satfat);
cards;

    DATA HERE

proc sort; by treatmen;

proc capability graphics;
comphistogram satfat / class = treatmen;
title NHANES Data (1=disease);

proc capability graphics;
comphistogram lsatfat / class = treatmen;
title NHANES Data (1=disease);


proc univariate plot;
var satfat lsatfat;
by treatmen;

run;