MyMathLib series (corrected two functions) and mymathlib correction

MyMathLib series (corrected two functions) and mymathlib correction

There is a problem with the judgment condition in the determining element. The corrected code is provided here:

1) MyMathLib. LinearAlgebra. CalcDeterminant Method

/// <Summary> // calculate the determinant of the triangle method, /// </summary> /// <param name = "Determinants"> rank N </param> /// <returns> calculation result </returns> public static double calcDeterminant (double [,] determinants) {int theSign = 1; // Positive and Negative symbols. If you need to change, the converted symbols are recorded. int theN = Determinants. getLength (0); // from column 1st to column theN-1 for (int I = 0; I <theN-1; I ++) {// from row theN-1 to row I + 1, change D [j, I] to 0 for (int j = theN-1; j> I; j --) {// if the current value is 0, it will not be processed. Continue to process One line if (Determinants [j, I] = 0) {continue;} // revised part: // if the top left neighbor element [J-1, the I-1] And the elements on its left are both 0 to be exchanged // since all the elements on the left of the current element are zero, so if you want to swap it, it cannot generate a non-zero number on the left of the row, // The upper left neighbor and all its elements must be 0. var theCanDo = true; for (int s = I-1; s> = 0; s --) {if (Determinants [j-1, s]! = 0) {theCanDo = false; break;} if (theCanDo) {// if the previous line of [j, I] [J-1, if the value of I] is 0, if (Determinants [j-1, I] = 0) is exchanged {// each time the value of the determinant remains the same, the opposite sign is theSign = 0-theSign; for (int k = 0; k <theN; k ++) {double theTmpDec = Determinants [j, k]; Determinants [j, k] = Determinants [j-1, k]; Determinants [j-1, k] = theTmpDec ;}} else {// subtract the product of the previous row and theRate from the current row. Double theRate = Math. round (Determinants [j, I]/Determinants [j-1, I], ConstDef. decimals); for (int k = 0; k <theN; k ++) {Determinants [j, k] = Math. round (Determinants [j, k]-Determinants [j-1, k] * theRate, ConstDef. decimals) ;}}}}// the result is the product of the elements on the diagonal line. Pay attention to symbol processing. Double theRetDec = theSign; for (int I = 0; I <theN; I ++) {theRetDec * = Determinants [I, I];} return theRetDec ;}

2. MyMathLib. LinearAlgebra. EquationsElimination

/// <Summary> // the element of the equations. The final column is the coefficient, and the result is in CoefficientDeterminant. /// this algorithm can also be used to calculate the rank of the matrix. /// </summary> /// <param name = "CoefficientDeterminant"> array of equations coefficient </param> public static void EquationsElimination (double [,] CoefficientDeterminant) {var theRowCount = CoefficientDeterminant. getLength (0); var theColCount = CoefficientDeterminant. getLength (1); int theN = theRowCount; int theE = theColCount-1; // from column 1st TO E-1 column, the last column does not need to be processed. for (int I = 0; I <theE; I ++) {// from row theN-1 to row 1st, change D [j, I] to 0 in sequence, it should be noted that: // if the first J-1 line, all the left elements are 0 to continue switching. for (int j = theN-1; j> 0; j --) {// if the current value is 0, it is not processed. Continue to process the previous line if (CoefficientDeterminant [j, i] = 0) {continue;} // ***** added here the condition for determining whether to continue switching the consumer element: // if the last left neighbor element [J-1, the I-1] And the elements on its left are both 0 to be exchanged // since all the elements on the left of the current element are zero, so if you want to swap it, it cannot generate a non-zero number on the left of the row, // The upper left neighbor and all its elements must be 0. var theCanDo = true; for (int s = I-1; s> = 0; S --) {if (CoefficientDeterminant [j-1, s]! = 0) {theCanDo = false; break;} if (theCanDo) {// if the previous line of [j, I] [J-1, if the value of I] is 0, if (CoefficientDeterminant [j-1, I] = 0) {for (int k = 0; k <= theE; k ++) // here the constant is exchanged, So k <= theE {double theTmpDec = CoefficientDeterminant [j, k]; CoefficientDeterminant [j, k] = CoefficientDeterminant [j-1, k]; CoefficientDeterminant [j-1, k] = theTmpDec;} else {// subtract the product of the previous row and theRate from the current row. // Var theRate = CoefficientDeterminant [j, I]/CoefficientDeterminant [j-1, I]; // for (int k = 0; k <= theE; k ++) // here the constant term is calculated, so k <= theE // {// CoefficientDeterminant [j, k] = CoefficientDeterminant [j, k]-CoefficientDeterminant [j-1, k] * theRate; //} // improvement: Multiplication can avoid the error var theRate2 = CoefficientDeterminant [j, I] caused by decimal conversion. var theRate1 = CoefficientDeterminant [j-1, I]; for (int k = 0; k <= theE; k ++) // The constant term is calculated here, so k <= theE {CoefficientDeterminant [j, k] = CoefficientDeterminant [j, k] * theRate1-CoefficientDeterminant [j-1, k] * theRate2 ;}}}}}}