Auto scaling

This section of the User Preferences Plot tab is used to set the required default behaviour for the pens that are set to a Scale Mode of "Auto".  

 

 

Control:

Default:

Purpose:

Strategy

Full Range

Options are:

  • "Full Range" - pens that are set to use Auto scaling will have their scales calculated using an algorithm that attempts to maximize the acreage used by each pen whilst minimising overlap between pens.  

Note: The effect is that pen scales are 'stretched' to fill the vertical height of the plot.

  • "Standard Deviation" -  pens that are set to use Auto scaling will have their scales calculated using an algorithm that uses the Standard Deviation.

Note: The effect is that the pen scales are less susceptible to over stating small deflections in the signal for a pen.

  • "Banded" -  pens that are set to use Auto scaling will have their scales calculated using an algorithm attempts to maximize the height of each pen using Auto Scale mode, whilst preserving a band at the top and bottom of the plot window. The width of the band is calculated as a percentage of the overall range of each pen. This tends to push the signal to the center of the plot window.  Three differing banding widths are provided:

    • "Narrow"

    • "Medium"

    • "Wide"

Note:  The effect of 'banding' is to reduce the illusion of point instability for pens using Auto Scaling.

Duration

Plot

This controls the data set used to calculate the scales for pens in "Auto" mode. Options are:

  • "Plot" - Scales are calculated using the data displayed on the plot (i.e. using the current plot duration).

  • "All History" - Scales are calculated using all available history.

Note: For performance reasons "All History" is only available when using a Sapphire Collector as the Data Source.

Pen Ordering

Ascending

This control whether pens should be added to the plot in Ascending (Pen 1 at the bottom, Pen 2 above it) or Descending (Pen 1 at the top, Pen 2 below it)order.

Pen Overlap

50%

The amount by which "Auto" pens should overlap.  A setting of 100% means the pens will all be centered vertically around the middle of the plot.  A setting of 0% means each pen will have its own 'band' on the plot and will not overlap with the adjacent pens.

Apply to Groups

Unchecked

Controls whether the Pen Overlap and Ordering options are applied just to pens (the default), or to the Scale Groups as well.

 

Tip:  Each of these setting can also be overridden at the plot level via the Plot Properties Preferences tab.