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function SGrey& ~, k: @, p/ E0 Z
x, V8 S$ @4 I4 \7 F, }+ {! {X0 = input('请输入原始负荷数据:'); %输入原始数据
# F6 `: \0 n+ m2 {' dn = length(X0); %原始n年数据% b! v- N2 v% ~ @! u* ?/ ]
# c' K( u, J$ i! ]# ?( f%累加生成
$ ^' ?& W- v* U/ K+ P5 l$ |X1 = zeros(1,n);+ r& r+ c8 s# T) n8 T. @1 v
for i = 1:n
7 ?6 \* Q1 Z* t, J if i == 1
( ?7 X9 N, J! [+ | X1(1,i) = X0(1,i);
! d- d0 S& o' ~9 s) a s% J q2 h else7 P+ j* u8 i/ n9 c6 x9 ?7 T
X1(1,i) = X0(1,i) + X1(1,i-1);
% h' W8 A M: r, A: ` end
: v7 U( |4 e2 _+ _; D; `# X: q+ c& a+ Send
6 I5 [ h- v& {X1
( y- y3 a8 }# ~& A3 s4 d) y
' @9 _. |6 A% R# p7 k8 I%计算数据矩阵B和数据向量Y# C- _7 s# x3 Q! B
B = zeros(n-1,2);
$ J" L; w6 Q2 v6 U1 p9 |' M5 XY = zeros(n-1,1);( w" N' U/ \3 p, {0 A
for i = 1:n-1
; D3 P/ B0 A. \! U B(i,1) = -0.5*(X1(1,i) + X1(1,i+1)); X1 v) V8 E; h4 P8 W+ A1 G
B(i,2) = 1;
+ R+ M+ i# t4 V( I! m, \ Y(i,1) = X0(1,i+1);
1 X( ^* D+ K ^- Dend- P& J9 e6 s: F
B,Y+ i; J3 M/ _+ A% e; Q9 a* k a
6 ]' j% h5 y; N) S5 P( D! N u
%计算GM(1,1)微分方程的参数a和u
9 g' z- R% b8 S' d& OA = zeros(2,1);1 O' }: N- s7 c! G# l! N
A = inv(B'*B)*B'*Y;
) ~" S) @( M% g2 m4 ]6 ]a = A(1,1);1 l$ b' c; F$ j9 O( N" S6 r
u = A(2,1);4 E3 o5 g5 t& |0 f8 M& @1 q
a,u
( S' ]9 `! N! ?; K4 L2 ?0 M- k' x( ?/ Y8 U6 c/ x
%建立灰色预测模型+ o! f5 P9 r( U. v* ]4 m5 C7 J
XX0(1,1) = X0(1,1);: x6 T8 N( `" r
for i = 2:n1 B; X/ T& g3 |* W
XX0(1,i) = (X0(1,1) - u/a)*(1-exp(a))*exp(-a*(i-1));
# M3 }0 x/ P/ V! `! t* v; Dend
w* ]- v; E2 O( K0 KXX0
$ m, u5 R. J, @%模型精度的后验差检验
3 n" k8 I! Y! H6 d, N; [e = 0; %求残差平均值
S( r! q; F1 y1 K( [$ O/ Afor i =1:n
2 a' X& W# W2 _5 ]# g e = e + (X0(1,i) - XX0(1,i));7 R5 V2 V. L+ Z7 q7 `$ b( r
end' d4 W r8 d N" x' h6 I7 j/ q4 R
e = e/n;
! }) ^$ M* j5 O& T5 Ye
, T; r9 P; m- A2 M1 Gaver = 0; %求历史数据平均值
0 R: ` x0 g" p& u6 r- I4 Ufor i = 1:n6 g) U& m) Q H, G+ c
aver = aver + X0(1,i);
! d, f9 o7 [+ ?' b2 j8 @0 K9 Xend( k# e0 d7 m$ z- C* G1 b% G: B
aver = aver / n;: S- n& B+ F; w. J$ I# Z/ |
aver
, L) Q5 H5 J/ i7 X* ps12 = 0; %求历史数据方差1 `5 Z0 U: `9 ^8 g- Z, R- \1 @% V
for i = 1:n U, ]8 u, T( f/ ?
s12 = s12 + (X0(1,i)-aver)^2;1 t9 z. _2 e7 q1 [
end3 P& ]- g: ^# Q+ m, o& A- D. n
s12 = s12 / n;
% e* j5 s; ]. o) ts12
; V# g% t+ {% q5 |) E os22 = 0; %求残差方差
) v- x5 y0 n' x) G Jfor i = 1:n* O$ [! Y) b: z' {! `
s22 = s22 + ((X0(1,i) - XX0(1,i)) - e)^2;# V( j( c# k0 b
end" I( I5 T+ z6 `
s22 = s22 / n;& _* C+ ~( k) b
s22$ j7 o1 x! ]% x- N, ?) G7 [6 x# L
C = s22 / s12; %求后验差比值' V: `! m: Y$ }. W
C
5 ~& G+ D _2 H$ q Rcout = 0; %求小误差概率
# P, Z! Y# t; _' @9 P2 _for i = 1:n5 |8 ~6 ?& P& d* d
if abs((X0(1,i) - XX0(1,i)) - e) < 0.6754*sqrt(s12)& _- O' H; S0 C# A; q6 c" N
cout = cout+1;0 v8 z! D. P9 J
else% r1 a! A. b, u$ t8 E' Q
cout = cout;, I7 \& Z% c, g0 u1 Y
end0 j* P" H5 g: \) E/ D
end
/ ~, _/ A; _7 w1 M5 J! G6 rP = cout / n;
7 t0 X3 B0 i/ j5 e& J) FP
2 Y2 o% x" e! _8 m) j. uif (C < 0.35 & P > 0.95)
7 W# {" J; `! V" I- [! g1 k disp('预测精度为一级');
8 ]5 Z, I" [' G6 h; N% W6 p m = input('请输入需要预测的年数: m = '); %预测往后各年的负荷
) }, c8 `& U. g, F' Y( n disp('往后m各年负荷为:');
" _# a& w( L7 {) F' b2 N) W, i/ } V f = zeros(1,m);
2 }4 a7 _; I [! U for i = 1:m% }1 y8 o8 F; n! O
f(1,i) = (X0(1,1) - u/a)*(1-exp(a))*exp(-a*(i+n-1));
" s' M- w; P; f; u" G end8 a( L2 k9 T/ D
f
! M& b6 s8 B7 @ C- welse
: i; I- {9 x. O3 u& E V disp('灰色预测法不适用');" @, U" U+ n: d, b5 N
end |