Study the systems sensitivity to some variable(s)?

To study systems sensitivity to variation of some variable you have to create new case where the variables values are altered. If you have more than one variable which are to be varied, the amount of different runs gets large very soon. The Variations tool lets you create all the combinations of new settings and writes the batch script that calls all these cases. The idea is simple: open the base case, modify the Multi and Shift of the variable (see here what they are in case you are not familiar) x times between values a and b. Do the same for all other desired variables, and also create a case for each combination of these. For example with three variables, two of which are varied three times and one is varied two times, we get 18 cases:

To use the tool, you must have a batch case of the system (remember that a 'batch' case can be made of only one simulation). Select from toolbar Tools→ Variations and the following window will open:

First thing you shold do is to load the batch file, by pressing Browse. If you use the button, the tool will show the variables used in the settings that are used in the batch. They are printed on the terminal:

Now you know what variables you can vary, and their index numbers. Next, in the Variations tool, add a line for each variable that is to be manipulated. Fill out the cells:

Index

this is either the exact name (in CAPS) or index number.

# of steps

How many elements should be in the array of different values (for this variable).

Multi min/max

Smallest and largest value for Multi (leave both to 1 if it is kept constant).

Shift min/max

Smallest and largest value for Shift (leave both to 1 if it is kept constant).

Note that the vector will vary both modifiers Multi and Shift simultaneously and you cannot create combinations of these. However it usually makes sense to use one of the either or at least keep the other as constant. Also remember that variables can be tied together and varied further in the Time dependent variables→ Input tab.

Logscale

Set to 1 if the vector has to be logarithmically spaced.

Next, press Create cases and Bob's your auntie.