5.1 Visualizing Data
-
tw1d
()
- illustrates
visual display devices for one-dimensional data
|
This quantlet illustrates a variety of visual display
techniques for one-dimensional data. To activate this,
the user should type in the following:
tw1d()
After this, the user should see the following windows:
The Display window gives a visual representation of a sample
data set already loaded into the computer -- the individual data
points are displayed at the bottom, and a histogram is displayed
above it. The Choose window gives some choices of options
available in data displays:
- Mean adds (or deletes) a bar in blue at the
bottom of the Display window where the mean is located.
- Median adds (or deletes) a bar in red at the bottom
of the Display window where the median is located.
- Mean boxplot adds (or deletes) a boxplot in blue
at the bottom of the Display window, with the box centered
on the mean, the box endpoints showing the mean plus and minus
one standard deviation, and the whiskers (i.e. the lines extending
to the left and right of the box) showing the mean plus and minus
two standard deviations.
- Median boxplot adds (or deletes) a boxplot in red
at the bottom of the Display window, with the middle line
of the box showing the median, the box endpoints showing the
quartiles (i.e. 25 and 75 percentiles), and the whiskers
showing the 2.5 and 97.5 percentiles.
- Normal distribution adds (or deletes) a graph of
the normal distribution in green over the histogram of the data.
- Extra Q-Q-Plot adds (or deletes) a quantile-quantile
plot, which graphs the quantiles of a normal distribution function
(with the sample mean and variance from the data) on the
-axis
against the quantiles of the original data on the
-axis.
- Square root gives a graph of the square root
transformation of the data (i.e. a histogram, etc., of the
square root of each value will be shown, rather than of the
actual value).
- Logarithmic gives a graph of the logarithmic
transformation of the data (i.e. a histogram, etc., of the
logarithm of each value will be shown, rather than of the
actual value).
- No transformation gives a graph of the
original data, to nullify the effects of the above two options.
The beginning student can use this quantlet to explore
various data display techniques.