擬合精度檢驗(yàn)

1、擬合精度檢驗(yàn)% 曲線擬合disp '* 圓柱齒輪復(fù)合齒形系數(shù) Yfs 與當(dāng)量齒數(shù) Zv 的關(guān)系 *'lx=input(' 選擇曲線類型： 1-雙曲線 ;2- 冪函數(shù) ;3- 負(fù)指數(shù) ;4-S 型;5- 指數(shù);6- 對(duì)數(shù) ;7- 直線 = ');x0=input(' 輸入插值點(diǎn)： x0 = ');n = 18;x=zeros(n); y=zeros(n); ys=zeros(n); ya=zeros(n); s=zeros(n); x=12 13 1415 16 17 18 19 20 25 30 35 40 45 50 60 70 80; y=5

2、.05 4.91 4.79 4.70 4.614.55 4.48 4.43 4.38 4.22 4.13 4.08 4.05 4.02 4.01 3.88 3.88 3.88;x1 = x(1); xn = x(n);for i = 1 : nya(i) = y(i);enddisp ' ZvYfs'for i = 1 : nzy = x(i) y(i);disp(zy)end% 繪制實(shí)驗(yàn)數(shù)據(jù)列表離散點(diǎn)圖 ( 紅色 , 圓點(diǎn) , 柵格 , 保持圖形 ) plot(x,y,'r.')gridhold on;% 根據(jù)曲線類型進(jìn)行變量代換for i = 1 : nsw

3、itch lxcase 1x(i) = 1 / x(i); y(i) = 1 / y(i);case 2x(i) = log(x(i); y(i) = log(y(i);case 3x(i) = 1 / x(i); y(i) = log(y(i);case 4 x(i) = exp(-x(i); y(i) = log(y(i);case 5 y(i) = log(y(i);case 6x(i) = log(x(i) / log(10);case 7endenddisp ' * 計(jì)算代換變量的累加與平方和 *' c = 0; d = 0; xc = 0; yc = 0; xy =

4、 0;for i = 1 : nc = c + x(i); d = d + y(i);xc = xc + x(i) A2; yc = yc + y(i) A2;xy = xy + x(i) * y(i);endcxy = c d xc ycxy;disp ' C-X C-Y C-XA2 C-YA2 C-(XY)A2' disp (cxy)dx = xc - c A2 / n;dy = yc - d A2 / n;dc = xy - c * d / n; lxy = dx dy dc;disp ' LxxLyyLxy' disp (lxy)disp ' *

5、計(jì)算擬合系數(shù)和常數(shù) *'b = dc / dx;fprintf (1,'擬合系數(shù) b = %3.6f n',b)a = (d - b * c) / n;fprintf (1,'代換常數(shù) a = %3.6f n',a)switch lxcase 1fprintf (1,'擬合常數(shù) a = %3.6f n',a)case 2g = exp(a);fprintf (1,'擬合常數(shù) a = %3.6f n',g) case 3g = exp(a);fprintf (1,'擬合常數(shù) a = %3.6f n',g) c

6、ase 4fprintf (1,'擬合常數(shù) a = %3.6f n',a)case 5g = exp(a);fprintf (1,'擬合常數(shù) a = %3.6f n',g) case 6fprintf (1,'擬合常數(shù) a = %3.6f n',a)case 7fprintf (1,'擬合常數(shù) a = %3.6f n',a)enddisp ' * 擬合效果和精度檢驗(yàn) *' r = dc / sqrt(dx * dy);fprintf (1,' 相關(guān)系數(shù) r = %3.6f n',r)d = 0; q

7、 = 0; yc = 0;for i = 1 : nys(i) = a + b * x(i);switch lxcase 1ys(i) = 1 / ys(i);case 2ys(i) = exp(ys(i);case 3ys(i) = exp(ys(i);case 4ys(i) = 1 / ys(i);case 5ys(i) = exp(ys(i);otherwiseends(i) = (ya(i) - ys(i) A 2;d = d + ya(i);q = q + s(i);yc = yc + ya(i) A2;enddy = yc - d * d / n;sgm = sqrt(q / (n

8、 - 2);rr = 1 - q / dy;fprintf (1,'剩余平方和 Q = %3.6f n',q)標(biāo)準(zhǔn)誤差 s = %3.6f n',sgm) fprintf (1,'相關(guān)指數(shù) R2 = %3.6ffprintf (1,'n',rr) switch lxcase 7f = (dy - q) * (n - 2) / q;fprintf (1,'統(tǒng)計(jì)量 F = %3.6f n',f)otherwiseend% 計(jì)算插值點(diǎn)函數(shù)值 , 根據(jù)選擇的曲線類型繪制擬合曲線 (藍(lán)色 , 實(shí)線) xx = x1 : 1 : xn;swi

9、tch lxcase 1y0 = x0 / (a * x0 + b );yy = xx ./ (a .* xx + b );case 2y0 = g * x0 A b;yy = g * xx .a b;case 3y0 = g * exp(b / x0);yy = g * exp(b ./ xx);case 4y0 = 1 / (a + b * exp(-x0);yy = 1 ./ (a + b .* exp(-xx);case 5y0 = g * exp(b * x0);yy = g * exp(b .* xx);case 6y0 = a + b * log(x0) / log(10); y

10、y = a + b .* log(xx) / log(10); case 7y0 = a + b * x0; yy = a + b .* xx; endfprintf (1,' 插值點(diǎn)函數(shù)值 y0 = %3.4f n',y0) plot(xx, yy,'b-')圖形標(biāo)題 - 擬合曲線類型和公式 字符黑體 , 公式斜體 switch lxcase 1 title('bf case 2 title('bf case 3 title('bf case 4 title('bf case 5 title('bf實(shí)驗(yàn)數(shù)據(jù)離散點(diǎn)圖實(shí)驗(yàn)數(shù)據(jù)離散點(diǎn)圖實(shí)驗(yàn)數(shù)據(jù)離散點(diǎn)圖實(shí)驗(yàn)數(shù)據(jù)離散點(diǎn)圖/ 雙曲線 it y=x/(ax+b)')/冪函數(shù)曲線it y=axAb'/ 負(fù)指數(shù)曲線 it y=aeAb/x')/ S 型