Statistical Tests for WIRE Data


Here is a description of the stattest program: stattest.txt.


Histogram Examples.

Stattest can be used to make a single histogram plot of a WIRE image file using the command: "stattest -h 1 -mdr 0 -mdc 0 -rmsr 0 -rmsc 0 -sfr 0 -sfc 0 -dft 0 -np 1" .

Here are some histogram plot examples of WIRE data using the "-histpoints" option in stattest. This options plots the individual data points within each histogram bin. The x value of each point is the image data value. The y value of each point the order number within the bin, i.e. the y value is incremented each time a point is assigned to a particular bin.

Here is a standard histogram plot of a raw WIRE image: hp-raw-1.ps .

Here is a standard histogram plot of a processed WIRE image: hp-proc-1.ps . Note how the points have discrete values near zero, and become more homogeneous away from zero. Also note that there are several hundred values which are exactly zero.

Here is a plot with a single bin from near zero to a value of 17: hp-proc-2.ps . (The x range for the plot was set with the "-histx" option in stattest.)

The shape of the histogram near zero will vary quite a bit depending on the position of the bin edges relative to these discrete values. Here are examples with different bin sizes: hp-proc-b20.ps, hp-proc-b30.ps, hp-proc-b50.ps, hp-proc-b90.ps, and hp-proc-b160.ps.