HP 3000 Manuals

HP LaserRX/MPE User's Manual: Analysis Software

Log Scaling Option 

The Log Scaling option appears on the Options dialog box.

The Options command appears under the Configure menu.


          Figure 10-38.  Log Scaling Option 

The Log Scaling option determines the vertical (Y-Axis) scaling on all
graphs that are drawn after making this selection.  The Y-Axis scale can
be linear or logarithmic (log).

Linear scaling is in effect when Log Scaling is not enabled (the Log
Scaling check box is clear).

Auto-scaling looks at whether log or linear is enabled on the Configure
Options dialog box and scales graphs accordingly.  This applies to the
Global Jobs & Sessions and all disc space graphs.

Linear scaling does the following:

   *   Represents scale units equally.

   *   Maintains visual relationships.

The linear scale, however, loses clarity on very small numbers and can
minimize perception of small variations between data points.

The System CPU Utilization graph that follows is drawn with a linear
Y-Axis (vertical) scale.


          Figure 10-39.  Global System CPU Utilization Graph (Linear Scale, Hatched Fill) 

Log scaling does the following:

   *   Emphasizes the variance in lower values on the graphs.

   *   Represents a wide range of values in a limited space.

   *   Tends to distort visual relationships.

The figure below is a System CPU Utilization graph drawn with a log
scale.


          Figure 10-40.  Global System CPU Utilization Graph (Log Scale, Hatched Fill) 

In a logarithmic scale, each increasing unit of measurement represents 10
times the value of the previous unit.

The starting unit is always higher than 0.

Each tick mark increments the scale by the value of the previous major
unit.  For example, if the scale starts at 1.0, the tick marks between
1.0 and 10.0 represent 2.0, 3.0, 4.0, and so on; between 10.0 and 100.0,
they represent 20.0, 30.0, 40.0, and so on.

When Log Scaling is enabled, subsequent graphs displayed with the Draw
Graphs command are scaled with a logarithmic Y-Axis.


NOTE  Changing the status of the Log Scaling check box does not affect
      the scale of graphs that have already been drawn.

MPE/iX 5.0 Documentation