integrate $\int dt$

Creates an integration (or stock) variable. Editable attributes include the variable's name and its initial value at $t=0$. The function to be integrated needs to be connected to the top port, labelled `$f$'. The bottom port, labelled `0', can optionally be connected to a constant, parameter or variable, which is used to specify the initial value of the integral.

Note that the units of the integral operator are given by the units of the input, multiplied by the time unit, but the units of the integral's variable are user specified. It is an error for these to be mismatched, and running dimensional analysis from the File menu will check for the consistency of this. Note that the user specified units in the integral variable can be used to dimension up the integral if the integral variable is connected to the integral's input.