5.1.3.1. Example: Duplicated test conditions

Description: Here we show a simple example involving two resets which are both triggered by the same test_variable and test_value condition: B == 3. Despite this, the resets alter different variables (they have different reset_variable attributes) and can thus be evaluated during the same loop, without needing to refer to the order attribute.

Note that:

• all elements are in the same component;

• the order values of resets are not shown; and

• all variables have dimensionless units.

component:
  ├─ math: ode(B, t) = 1
  │
  ├─ variable: A initially 1
  │   └─ reset: rule 1
  │       ├─ when B == 3
  │       └─ then A = 2
  │
  └─ variable: B initially 1
      └─ reset: rule 2
          ├─ when B == 3
          └─ then B = 1

See CellML syntax

<variable name="A" units="dimensionless" initial_value="1" />
<variable name="B" units="dimensionless" initial_value="1" />

<math>
    <apply><eq/>
        <diff>
            <ci>B</ci>
            <bvar>t</bvar>
        </diff>
        <cn cellml:units="dimensionless">1</cn>
    </apply>
</math>

<!-- Reset rule 1: -->
<reset variable="A" test_variable="B">
    <test_value>
        <cn units="cellml:dimensionless">3</cn>
    </test_value>
    <reset_value>
        <cn units="cellml:dimensionless">2</cn>
    </reset_value>
</reset>

<!-- Reset rule 2: -->
<reset variable="B" test_variable="B">
    <test_value>
        <cn units="cellml:dimensionless">3</cn>
    </test_value>
    <reset_value>
        <cn units="cellml:dimensionless">1</cn>
    </reset_value>
</reset>

At t = 2 the following situation occurs:

t	0	1	2
A	1	1	1
B	1	2	3

At this point, the integrator checks all reset rules, finding an active reset for both A and B. As a result, both values are updated:

t	0	1	2
A	1	1	1 → 2
B	1	2	3 → 1

Changes have been made, so a second cycle of reset evaluations is started. No active reset rules are found so model dynamics continue.

t	0	1	2	2 + dt	3
A	1	1	1 → 2	2	2
B	1	2	3 → 1	1 + dt	2