```
input accelerationFactor = 0.02;
input accelerationLimit = 0.2;
assert(accelerationFactor > 0, "'acceleration factor' must be positive: " + accelerationFactor);
assert(accelerationLimit >= accelerationFactor, "'acceleration limit' (" + accelerationLimit + ") must be greater than or equal to 'acceleration factor' (" + accelerationFactor + ")");
def state = {default init, long, short};
def extreme;
def SAR;
def acc;
switch (state[1]) {
case init:
state = state.long;
acc = accelerationFactor;
extreme = high;
SAR = low;
case short:
if (SAR[1] < high)
then {
state = state.long;
acc = accelerationFactor;
extreme = high;
SAR = extreme[1];
} else {
state = state.short;
if (low < extreme[1])
then {
acc = min(acc[1] + accelerationFactor, accelerationLimit);
extreme = low;
} else {
acc = acc[1];
extreme = extreme[1];
}
SAR = max(max(high, high[1]), SAR[1] + acc * (extreme - SAR[1]));
}
case long:
if (SAR[1] > low)
then {
state = state.short;
acc = accelerationFactor;
extreme = low;
SAR = extreme[1];
} else {
state = state.long;
if (high > extreme[1])
then {
acc = min(acc[1] + accelerationFactor, accelerationLimit);
extreme = high;
} else {
acc = acc[1];
extreme = extreme[1];
}
SAR = min(min(low, low[1]), SAR[1] + acc * (extreme - SAR[1]));
}
}
def transitionBull = state[1] == state.short and state == state.long;
def transitionBear = state[1] == state.long and state == state.short;
def count1 = if transitionBull then 1 else count1[1]+1;
def count2 = if transitionBear then 1 else count2[1]+1;
input label_text = "PSAR";
AddLabel(1, label_text + " - " + if transitionBull then count1 else count2,
if transitionBull then color.green
else color.red);
```