CS 110 -- Lab 2

NOTES: in the directions on this page, commands you should type appear in this font.

There are two primary goals of this lab session: first to further familiarize you with development tools you are using (the Linux Operating System and the XEmacs editor) and second, to work of the homework assignment. You should answer the questions posed on this page for your own purposes. However, do not hand this sheet in.

Linix:
Open a new terminal window and type each of the following commands. Be sure you understand what each command does and why. (Hint: read the attached "Unix cheat sheet"). Note: "subdirectory" in Linux is the same as "folder" in windows.

pwd
cd html
pwd
ls 
ls -l
cd ..
ls
cd html
ls
cp Hello.html a.html
more a.html
ls
rm a.html
more a.html
cp Hello.html a.html

XEmacs:
Once you have completed the Linux series of commands, open XEmacs and do the following
Note C-x means hold down the control key and hit the 'x' key. <RET> means hit the RETURN key
Hint: some tof this is explained in the "Emacs cheet sheet" which is attached.

C-x C-f html/a.html <RET>

what did this just do?

C-x k <RET>

what did this just do?

C-x C-f html/a.html <RET>
C-x C-f Hello.html

what did this just do? What happened to a.html? How can you get back to a.html?
Occasionally a tab will not appear, you can also get back to a.html by entering C-x b a.html <RET>

make sure you are seeing the buffer Hello.html (you can tell by looking at the name near the bottom of the XEmacs screen

C-x k

What did this just do?

C-k C-k

what did this just do?

what did this do?

<up arrow>
C-k C-k C-k C-k C-k C-k

what did this do?

C-y
drag the mouse over a section of text -- the text will get a grey background
C-w

what happened

C-y
drag the mouse over a section of text -- the text will get a grey background
<ESC>-w
C-y

what happened

Quit XEmacs
DONE -- go on to working on homework.

Homework:
The following should give you some clues about ahow to proceed. Note, that while this is a good start, it is not a good finish. The variable names are lousy, there is not documentation, it only draws one bar, ...

<>import java.awt.*;
<>import java.applet.Applet;<>
<>public class OneBar extends Applet<>
{
    public void paint(Graphics hippo)
    {
        int d1 = 4;
        int d2 = 12;
        int d3 = 7;
        int yScaleMax = 15; // I chose this to be a little bigger than my biggest value
        int barWidth = 300 / 3; // the size of my applet / 3, because I have 3 data points
        float barHeight = (float)d1 / yScaleMax * 300;
        hippo.fillRect(0, 300-(int)barHeight, barWidth, (int)barHeight);
    }
}