1. Select value from index 1.1. Purpose The Select given index filter may be used to pick a given X or Y-value from a time-series at a given index. The user selects the index and which axis to pick the value from. For example if Y-axis and Index 0 is selected, the first value from the-Y-axis is selected. 1.2. Input Any signal except constants (see Signal Types ). 1.3. Output The X or Y-value for each input signal at the given index.