Data update

Task/Multiple-regression/BASIC256/multiple-regression.basic

@@ -0,0 +1,70 @@
+arraybase 0
+N = 14: M = 2: Q = 3 # number of points and M.R. polynom degree
+
+dim X(N+1) # data points
+X[0] = 1.47 : X[1] = 1.50 : X[2] = 1.52
+X[3] = 1.55 : X[4] = 1.57 : X[5] = 1.60
+X[6] = 1.63 : X[7] = 1.65 : X[8] = 1.68
+X[9] = 1.70 : X[10] = 1.73 : X[11] = 1.75
+X[12] = 1.78 : X[13] = 1.80 : X[14] = 1.83
+dim Y(N+1) # data points
+Y[0] = 52.21 : Y[1] = 53.12 : Y[2] = 54.48
+Y[3] = 55.84 : Y[4] = 57.20 : Y[5] = 58.57
+Y[6] = 59.93 : Y[7] = 61.29 : Y[8] = 63.11
+Y[9] = 64.47 : Y[10] = 66.28 : Y[11] = 68.10
+Y[12] = 69.92 : Y[13] = 72.19 : Y[14] = 74.46
+dim S(N+1): dim T(N+1) # linear system coefficient
+dim A(M+1, Q+1)    # system to be solved
+dim p(M+1, Q+1)
+
+for k = 0 to 2 * M
+	S[k] = 0: T[k] = 0
+	for i = 0 to N
+		S[k] = S[k] + X[i] ^ k
+		if k <= M then T[k] = T[k] + Y[i] * X[i] ^ k
+	next i
+next k
+
+# build linear system
+for fila = 0 to M
+	for columna = 0 to M
+		A[fila, columna] = S[fila + columna]
+	next columna
+	A[fila, columna] = T[fila]
+next fila
+
+print "Linear system coefficents:"
+for i = 0 to M
+	for j = 0 to M + 1
+		print rjust(A[i, j], 14.1);
+	next j
+	print
+next i
+
+for j = 0 to M
+	for i = j to M
+		if A[i, j] <> 0 then exit for
+	next i
+	if i = M + 1 then print: print "SINGULAR MATRIX '" : end
+	for k = 0 to M + 1
+		p[j,k] = A[i,k] : A[i,k] = p[j,k] : A[j,k] = A[i,k]
+	next k
+	z = 1 / A[j, j]
+	for k = 0 to M + 1
+		A[j, k] = z * A[j, k]
+	next k
+	for i = 0 to M
+		if i <> j then
+			z = -A[i, j]
+			for k = 0 to M + 1
+				A[i, k] = A[i, k] + z * A[j, k]
+			next k
+		end if
+	next i
+next j
+
+print: print "Solutions:"
+for i = 0 to M
+	print rjust(A[i, M + 1], 16.7);
+next i
+end