Power Analysis of Independent-Samples T Test: Plot
The Plot dialog provides options for controlling the plots that are output to illustrate the two and three-dimensional power by sample ratio, effect size, or mean difference charts. The dialog also controls the vertical and horizontal rotation degrees for three-dimensional charts.
- Two-Dimensional Plot
-
- Power estimation versus sample size ratio/Power estimation versus sample size
- When enabled, this optional setting provides options for controlling the two-dimensional power
by sample size ratio chart. The additional settings are not available when multiple power values
have been specified (Power estimation versus sample size). The setting is
disabled by default.
- Range of sample size ratio
- When selected, the lower and upper bound options are available. When no integer values are
specified for the Lower bound or Upper bound fields,
the default plot range of the sample size is used.
- Lower bound
- Controls the lower bound for the two-dimensional power by sample size ratio chart. The value must be between 0.01 and 100 and cannot be greater than the Upper bound value.
- Upper bound
- Controls the upper bound for the two-dimensional power by sample size ratio chart. The value must be between 0.01 and 100 and must be greater than the Lower bound value.
- Power estimation versus effect size (or mean difference)
- By default, this optional setting is disabled. When enabled, the chart displays in the output.
When no integer values are specified for the Lower bound or Upper
bound fields, the default plot range of the effect size (or mean difference) is used.
- Range of effect size (or mean difference)
- When selected, the lower and upper bound options are available.
- Lower bound
- Controls the lower bound for the two-dimensional power by effect size chart. The value must be greater than, or equal to, -5.0 and cannot be greater than the Upper bound value.
- Upper bound
- Controls the upper bound for the two-dimensional power by effect size chart. The value must be greater than the Lower bound value and cannot be greater than 5.0.
- Three-Dimensional Plot
-
- Power estimation versus
- Provides options for controlling the three-dimensional power by sample size ratio (x-axis) and
effect size (y-axis) chart, the vertical/horizontal rotation settings, and the user specified plot
range of sample/effect size. This setting is disabled by default.
- Effect size (or mean difference) on x-axis and sample size on y-axis
- The optional setting controls the three-dimensional power by sample size ratio (x-axis) and effect size (y-axis) chart. By default, the chart is suppressed. When specified, the chart displays.
- Effect size (or mean difference) on y-axis and sample size on x-axis
- The optional setting controls the three-dimensional power by sample size (y-axis) and effect size (x-axis) chart. By default, the chart is suppressed. When specified, the chart displays.
- Vertical rotation
- The optional setting sets the vertical rotation degrees (clockwise from the left) for the three-dimensional chart. You can use the mouse to rotate the chart vertically. The setting takes effect when the three-dimensional plot is requested. The value must be a single integer value less than or equal to 359. The default value is 10.
- Horizontal rotation
- The optional setting sets the horizontal rotation degrees (clockwise from the front) for the three-dimensional chart. You can use the mouse to rotate the chart horizontally. The setting takes effect when the three-dimensional plot is requested. The value must be a single integer value less than or equal to 359. The default value is 325.
- Range of sample size ratio
- When selected, the lower and upper bound options are available. When no integer values are
specified for the Lower bound or Upper bound fields,
the default plot range of the sample size is used.
- Lower bound
- Controls the lower bound for the three-dimensional power by sample size ratio chart. The value must be between 0.01 and 100 and cannot be greater than the Upper bound value.
- Upper bound
- Controls the upper bound for the three-dimensional power by sample size ratio chart. The value must be between 0.01 and 100 and must be greater than the Lower bound value.
- Range of effect size (or mean difference)
- When selected, the lower and upper bound options are available. When no integer values are
specified for the Lower bound or Upper bound fields,
the default plot range of the effect size is used.
- Lower bound
- Controls the lower bound for the three-dimensional power by effect size chart. The value must be greater than, or equal to, -5.0 and cannot be greater than the Upper bound value.
- Upper bound
- Controls the upper bound for the three-dimensional power by effect size chart. The value must be greater than the Lower bound value and cannot be greater than 5000.