Help for Statiscope 1.0beta8 Applet
- Getting Started
- At the text boxes near by the Simulate button, enter 170
in the Number box, 90 in the Mean box, and 30 in the Std.
dev. box. Click the Simulate button. Click through the
radio buttons Distribute, Probability mass, etc.
Click the button Sort to sort and then on Clear data to
empty the list. The Stop button is used to interrupt lengthy
- Data Entry
- Enter a number in the text box Data/Location and press
Enter. Continue to enter a few numbers. Decimal numbers require a point
as a decimal separator. You can enter several numbers at a time by
separating them with commas (or space).
Try e.g. this list: 5, 3.5, 9, 3.5
You can mark it and copy it with Ctrl+C in Windows (Cmd+C in Macintosh,
only marking in X-windows), click the Data/Location box and
paste the clip with Ctrl+V in Windows (Cmd+V in Macintosh, the middle
mousebutton in X-windows) and press Enter. This is regrettably the only
method you can use to copy and paste in a Java applet.
It is possible to delete numbers in the list by clicking them and
pressing the Delete or Backspace key. You can also insert numbers into
the list by clicking where you want the new number to appear and
pressing the I key. (Insert would have been more appropriate but it
regrettably won't work in Java.) When you are in the list you can move
up and down by pressing the up and down arrow keys, but this also works
when you are in the text box Data/Location. If you edit a value
and press Enter, the value is updated. To add new values you must be at
the end of the list.
In the application you can also use the functions of the File
menu. Open lets you choose a file to load. Save is used
to store the data to a file.
Another method of getting data into the program is to write an URL in
the Data/Location box. You can open a new browser and bring up
(Click the link, and a new browser window is opened automatically.)
Click to bring up foton.dat, copy the URL from the browser and paste it
into Statiscope's Data/Location box and press Enter. Now the
first column will be read into the program. If you want to load another
column, enter the URL comma the column number.
will read the second column.
A special link can be used to get Statiscope to load your data
automatically. This is explained on the Statiscope
URL Encoder page.
The last method, simulation, has already been described at "Getting
Started". The simulation yield normally distributed numbers.
- Statistical Charts
- By clicking the radio buttons at the left, the corresponding
statistical chart is showed. There are real charts and there are text
diagrams. The scales are automatically calculated, but the ticks on the
x-axes can be manipulated by pressing the < and > buttons. The
distance between the ticks is always 1, 2, or 5 times a power of ten.
If the check box Rel. is checked the corresponding relative
function is showed instead of the absolute. If the check box Theo.
is checked the corresponding theoretical function based on the normal
distribution with the same mean and standard deviation as the measured
data is showed.
- This shows the empirical distribution function, that is the
height of the graph for a certain x-value is the probability that a
value will be less than or equal to that value.
- Probability mass
- This shows the probability mass function, that is the number of
data points with a certain x-value. If Rel. is checked it is
instead the probability of the value. This is a bar diagram.
- This shows the density function, that is the number of data
points that fall within the different intervals which the x-axis is
divided into. If Rel. is checked it is instead the probability
of falling within the interval is showed. This is a histogram.
- Box plot
- This shows a box plot over the data. The vertical lines in the
box plot correspond to - from left - minimum, 1st quartile, median (or
2nd quartile), 3rd quartile, and maximum. This gives a summary of the
- Stem and leaf
- This shows a stem and leaf diagram over the data. It shows a kind
of lying histogram. It works best for positive integers when the
difference between maximum and minimum is below a few hundreds. It's
easiest explained by an example.
- Data listing
- This is the cat among the ermines. It simply shows the same data
as in the list. The purpose of this is that you can copy data from this
print-out and paste it into an editor, to perhaps finally publish your
data on the net.
- The number of data points.
- The sum of all data points.
- The mean, or empirical expectation value, that is the sum of the
data points divided by the number of data points.
- Sam. std. dev.
- The sample standard deviation, this is the measure of the spread
in the data which is used most often. Especially when the data is a
sample from a larger or infinite population. It is the root of the sum
of the squares of the differences between the data points and the mean
divided by the number of data points less one.
- Pop. std. dev.
- The population standard deviation, is used if the data is
collected from the whole population. It's seldomly used in practice. It
is root of the sum of the squares of the differences between the data
points and the mean divided by the number of data points.
- The least of the data points.
- Quartile 1
- The 1st quartile, that is the median of the data points between
the least value and the median of all data points.
- The median, that is if you sort the data it is the middle value
or the mean of the two middle values, depending on if the number is odd
- Quartile 3
- The 3rd quartile, that is the median of the data points between
the median of all data points and the largest value.
- The largest value.
- Confidence Interval and Hypothesis Testing
- The percentage of the confidence intervals does only affect the
confidence intervals and not the hypothesis testings. But the radio
buttons Lower, Middle, and Upper affects both
the confidence intervals and the hypothesis testings.
[t- and Chi-2-distributions are used. The algorithms for Chi-2 will
probably need some improvement.]
- Confidence Interval
- Confidence interval in general means that the probability that
the real value should be within the interval is equal to the Confidence
percentage (e.g. 95%).
Mean is the confidence interval for the standard deviation.
You can determine lower, two-sided, and upper confidence intervals, by
selecting Lower, Middle, and Upper,
- Hypothesis Testing
- By hypothesis testing you can examine if a certain hypothesis
should be accepted or rejected. If the alternative hypothesis is used
as a new hypothesis and is rejected, the former hypothesis is
The hypothesis is H0 and the alternative hypothesis is H1.
H0: real value <= hypothesis, H1: real value > hypothesis,
H0: real value = hypothesis, H1: real value <> hypothesis,
H0: real value >= hypothesis, H1: real value < hypothesis,
The hypothesis is rejected if the p-value is less than a certain
fixed level e.g. 0.05, called the alpha-level. The higher the
level the stricter the test. The hypotheses is entered in the boxes
below Hypothesis and the p-value is showed in the boxes below P-value.
- Right Browser
- For the applet Netscape Navigator 3.01 is recommended, earlier
versions have had problems with the behaviour of the list box. If
certain controls should not be painted you can try to minimize the
browser and restore it again. An alternative browser is Microsoft
Internet Explorer 3.0.
- Comments Welcome
- Bug reports and suggestions for improvements on the program
Statiscope and this documentation is gratefully received by Mikael Bonnier.
- THIS PROGRAM IS USED AT YOUR OWN RISK. IT SHOULD SPECIFICALLY NOT
BE USED IN HIGH RISK ACTIVITY SUCH AS DIAGNOSIS AND TREATMENT OF
PATIENTS, OR THE OPERATION OF NUCLEAR FACILITIES OR WEAPONS SYSTEMS.
The program Statiscope and this documentation is Copyright
© 1996-1997 by Mikael Bonnier, Lund, Sweden. All rights
WWW home page: http://www.df.lth.se.orbin.se/~mikaelb/