This commit is contained in:
Hendrik Schutter 2024-12-26 22:40:20 +01:00
parent e790660c36
commit 06c6612ef6

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@ -36,7 +36,7 @@ void taskInput(void *pvParameters);
void initMeasurement(sMeasurement *pMeasurement);
void updateAverage(sMeasurement *pMeasurement);
void updatePrediction(sMeasurement *pMeasurement);
float linearRegressionPredict(const float *samples, size_t count, float futureIndex);
float linearRegressionPredict(const float *samples, size_t count, size_t bufferIndex, float futureIndex);
void initInputs(void)
{
@ -162,6 +162,7 @@ void updatePrediction(sMeasurement *pMeasurement)
predict60s->fValue = linearRegressionPredict(
predict60s->samples,
predict60s->bufferCount,
predict60s->bufferIndex,
predict60s->bufferCount + 60.0f);
}
@ -264,7 +265,7 @@ void taskInput(void *pvParameters)
}
}
float linearRegressionPredict(const float *samples, size_t count, float futureIndex)
float linearRegressionPredict(const float *samples, size_t count, size_t bufferIndex, float futureIndex)
{
if (count == 0)
return 0.0f; // No prediction possible with no data
@ -273,8 +274,11 @@ float linearRegressionPredict(const float *samples, size_t count, float futureIn
for (size_t i = 0; i < count; i++)
{
float x = (float)i; // Time index
float y = samples[i]; // Sample value
// Calculate the circular buffer index for the current sample
size_t circularIndex = (bufferIndex + i + 1) % count;
float x = (float)i; // Time index
float y = samples[circularIndex]; // Sample value
sumX += x;
sumY += y;
@ -284,8 +288,8 @@ float linearRegressionPredict(const float *samples, size_t count, float futureIn
// Calculate slope (m) and intercept (b) of the line: y = mx + b
float denominator = (count * sumX2 - sumX * sumX);
if (fabs(denominator) < 1e-6) // Avoid division by zero
return samples[count - 1]; // Return last value as prediction
if (fabs(denominator) < 1e-6) // Avoid division by zero
return samples[bufferIndex]; // Return the latest value as prediction
float m = (count * sumXY - sumX * sumY) / denominator;
float b = (sumY - m * sumX) / count;