/* MIT License Copyright (c) 2021-22 Magnus Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions: The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software. THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */ #include #include #include #include int createFormula(RawFormulaData &fd, char *formulaBuffer, int formulaBufferSize, int order) { int noAngles = 0; RawFormulaData fd2; // Check how many valid values we have got and make sure we have a full // series. for (int i = 0; i < FORMULA_DATA_SIZE; i++) { if (fd.a[i]) { fd2.a[noAngles] = fd.a[i]; fd2.g[noAngles] = fd.g[i]; noAngles++; } } #if LOG_LEVEL == 6 && !defined(CALC_DISABLE_LOGGING) Log.verbose( F("CALC: Trying to create formula using order = %d, found %d angles" CR), order, noAngles); #endif if (noAngles < 3) { writeErrorLog("CALC: Not enough values for deriving formula"); return ERR_FORMULA_NOTENOUGHVALUES; } else { double coeffs[order + 1]; int ret = fitCurve(order, noAngles, fd2.a, fd2.g, sizeof(coeffs) / sizeof(double), coeffs); // Returned value is 0 if no error if (ret == 0) { #if LOG_LEVEL == 6 && !defined(CALC_DISABLE_LOGGING) Log.verbose(F("CALC: Finshied processing data points, order = %d." CR), order); #endif // Print the formula based on 'order' if (order == 4) { snprintf(formulaBuffer, formulaBufferSize, "%.8f*tilt^4+%.8f*tilt^3+%.8f*tilt^2+%.8f*tilt+%.8f", coeffs[0], coeffs[1], coeffs[2], coeffs[3], coeffs[4]); } else if (order == 3) { snprintf(formulaBuffer, formulaBufferSize, "%.8f*tilt^3+%.8f*tilt^2+%.8f*tilt+%.8f", coeffs[0], coeffs[1], coeffs[2], coeffs[3]); } else if (order == 2) { snprintf(formulaBuffer, formulaBufferSize, "%.8f*tilt^2+%.8f*tilt+%.8f", coeffs[0], coeffs[1], coeffs[2]); } else { // order == 1 snprintf(formulaBuffer, formulaBufferSize, "%.8f*tilt+%.8f", coeffs[0], coeffs[1]); } #if LOG_LEVEL == 6 && !defined(CALC_DISABLE_LOGGING) Log.verbose(F("CALC: Formula: %s" CR), formulaBuffer); #endif bool valid = true; for (int i = 0; i < 5; i++) { if (fd.a[i] == 0 && valid) break; double g = calculateGravity(fd.a[i], 0, formulaBuffer); double dev = (g - fd.g[i]) < 0 ? (fd.g[i] - g) : (g - fd.g[i]); // If the deviation is more than 2 degress we mark it as failed. if (dev * 1000 > myAdvancedConfig.getMaxFormulaCreationDeviation()) { writeErrorLog( "CALC: Validation failed on angle %.2f, deviation too large %.4f " "SG, formula order %d", fd.a[i], dev * 1000, order); valid = false; } } if (!valid) { return ERR_FORMULA_UNABLETOFFIND; } Log.info(F("CALC: Found formula '%s'." CR), formulaBuffer); return 0; } } writeErrorLog("CALC: Internal error finding formula."); return ERR_FORMULA_INTERNAL; } double calculateGravity(double angle, double temp, const char *tempFormula) { const char *formula = myConfig.getGravityFormula(); if (tempFormula != 0) { #if LOG_LEVEL == 6 && !defined(CALC_DISABLE_LOGGING) Log.verbose(F("CALC: Using temporary formula." CR)); #endif formula = tempFormula; } #if LOG_LEVEL == 6 && !defined(CALC_DISABLE_LOGGING) Log.verbose(F("CALC: Calculating gravity for angle %F, temp %F." CR), angle, temp); Log.verbose(F("CALC: Formula %s." CR), formula); #endif if (strlen(formula) == 0) return 0.0; // Store variable names and pointers. te_variable vars[] = {{"tilt", &angle}, {"temp", &temp}}; int err; // Compile the expression with variables. te_expr *expr = te_compile(formula, vars, 2, &err); if (expr) { double g = te_eval(expr); te_free(expr); #if LOG_LEVEL == 6 && !defined(CALC_DISABLE_LOGGING) char s[20]; snprintf(&s[0], sizeof(s), "%.8f", g); Log.verbose(F("CALC: Calculated gravity is %s." CR), &s[0]); #endif return g; } writeErrorLog("CALC: Failed to parse gravity expression %d", err); return 0; } // Do a standard gravity temperature correction. This is a simple way to adjust // for differnt worth temperatures. This function uses C as temperature. // // Source: https://homebrewacademy.com/hydrometer-temperature-correction/ double gravityTemperatureCorrectionC(double gravitySG, double tempC, double calTempC) { #if LOG_LEVEL == 6 && !defined(CALC_DISABLE_LOGGING) Log.verbose(F("CALC: Adjusting gravity based on temperature, gravity %F, " "temp %F, calTemp %F." CR), gravitySG, tempC, calTempC); #endif double tempF = convertCtoF(tempC); double calTempF = convertCtoF(calTempC); const char *formula = "gravity*((1.00130346-0.000134722124*temp+0.00000204052596*temp^2-0." "00000000232820948*temp^3)/" "(1.00130346-0.000134722124*cal+0.00000204052596*cal^2-0." "00000000232820948*cal^3))"; // Store variable names and pointers. te_variable vars[] = { {"gravity", &gravitySG}, {"temp", &tempF}, {"cal", &calTempF}}; int err; // Compile the expression with variables. te_expr *expr = te_compile(formula, vars, 3, &err); if (expr) { double g = te_eval(expr); te_free(expr); #if LOG_LEVEL == 6 && !defined(CALC_DISABLE_LOGGING) char s[80]; snprintf(&s[0], sizeof(s), "Corrected gravity=%.8f, input gravity=%.8f", g, gravitySG); Log.verbose(F("CALC: %s." CR), &s[0]); #endif return g; } writeErrorLog( "CALC: Failed to parse expression for gravity temperature correction %d", err); return gravitySG; } // EOF