89 lines
1.6 KiB
C
89 lines
1.6 KiB
C
#ifndef _MATH_GUARD
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#define _MATH_GUARD
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typedef struct Stats {
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float mean;
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float std;
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} Stats;
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float
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calculateEMA(float nextValue, float emaLast, float smooth)
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{
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if(smooth < 0 || smooth > 1) // validate smooth value
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{
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printf("Smoothing value of %f not valid, between 0 and 1 required", smooth);
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return 0;
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}
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return (smooth * nextValue) + ((1 - smooth) * emaLast);
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}
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int
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ceil(float in) // self-implement ceil func, no math.h
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{
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int num = (int) in;
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if(in - num > 0) num++;
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return num;
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}
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float
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sqrt(float in) // self-implement sqrt func, no math.h
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{
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float sqrt = in/2;
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float temp = 0;
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while(sqrt != temp)
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{
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temp = sqrt;
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sqrt = (in/temp + temp) / 2;
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}
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return sqrt;
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}
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float
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calculateMean(float buffer[], int length)
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{
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if(length <= 0)
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{
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printf("%i items is not valid length\n", length);
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return 0;
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}
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/* SUM */
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float sum = 0;
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int i;
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for(i = 0; i < length; i++)
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{
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sum += buffer[i];
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}
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return sum / length; // DIVIDE ON RETURN
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}
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Stats
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calculateStdDev(float buffer[], int length)
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{
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Stats stats;
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if(length <= 0)
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{
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printf("%i items is not valid length\n", length);
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return stats;
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}
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stats.mean = calculateMean(buffer, length);
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float sum = 0;
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int i;
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for(i = 0; i < length; i++)
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{
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float diffFromMean = buffer[i] - stats.mean; // (xi - mu)
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sum += diffFromMean*diffFromMean; // Sum(diff squared)
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}
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stats.std = sqrt(sum/length);
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return stats;
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}
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#endif
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