The available options for SISOTOOL visualizations using SISOINIT are limited to those which display the poles and zeros of a system. These options are:
Open-Loop: 'rlocus', 'bode', 'nichols'
Closed-Loop: 'bode'
That is, only the above plots can be toggled on or off using SISOINIT.
The reason behind this is that all other analysis plots, such as step responses, are opened on a different LTI Viewer window. Therefore, the ability to automatically open up any LTI Viewer plots with the SISOTOOL command is currently unavailable in Control System Toolbox 9.0 (R2010b).
The closest thing that can be done is to save a SISOTOOL Design Task to a MAT File using "File > Save" from the main SISOTOOL window. This task can then be reloaded at a later time and the selected Step response plots will be saved in the Analysis Plots tab for future use.
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