#include?
#include?
#include?

#define?M?10

void?polyfit（int?ndouble?*xdouble?*yint?poly_ndouble?a[]）;

main（）
{
int?ijnpoly_n=2;
double?x[M]y[M];
double?a[3];

printf（“Input?n?of?xy:“）;
scanf（“%d“&n）;
printf（“Input?x:“）;
for（i=0;i	scanf（“%d“&x[i]）;
printf（“Input?y:“）;
for（i=0;i	scanf（“%d“&y[i]）;

system（“cls“）;
polyfit（nxypoly_na）;

for?（i=0;i?????printf（“a[%d]=%g\n“ia[i]）;
getch（）;
}


/*==================polyfit（nxypoly_na）===================*/
/*=======擬合y=a0+a1*x+a2*x^2+……+apoly_n*x^poly_n========*/
/*=====n是數據個數?xy是數據值?poly_n是多項式的項數======*/
/*===返回a0a1a2……a[poly_n]，系數比項數多一（常數項）=====*/
void?polyfit（int?ndouble?x[]double?y[]int?poly_ndouble?a[]）
{
int?ij;
double?*tempx*tempy*sumxx*sumxy*ata;
void?gauss_solve（int?ndouble?A[]double?x[]double?b[]）;
tempx=calloc（nsizeof（double））;
sumxx=calloc（poly_n*2+1sizeof（double））;
tempy=calloc（nsizeof（double））;
sumxy=calloc（poly_n+1sizeof（double））;
ata=calloc（（poly_n+1）*（poly_n+1）sizeof（double））;
for?（i=0;i?????{
??????tempx[i]=1;
??????tempy[i]=y[i];
?????}
for?（i=0;i<2*poly_n+1;i++）
?????for?（sumxx[i]=0j=0;j???{
????sumxx[i]+=tempx[j];
????tempx[j]*=x[j];
???}
for?（i=0;i????for?（sumxy[i]=0j=0;j???{
????sumxy[i]+=tempy[j];
????tempy[j]*=x[j];
???}
for?（i=0;i?????for?（j=0;jata[i*（poly_n+1）+j]=sumxx[i+j];
gauss_solve（poly_n+1ataasumxy）;

free（tempx）;
free（sumxx）;
free（tempy）;
free（sumxy）;
free（ata）;
}

void?gauss_solve（int?ndouble?A[]double?x[]double?b[]）
{
int?ijkr;
double?max;
for?（k=0;k?????{
??????max=fabs（A[k*n+k]）;?/*find?maxmum*/
??????r=k;
??????for?（i=k+1;i???if?（max??????{
???????max=fabs（A[i*n+i]）;
???????r=i;
??????}
??????if?（r!=k）
for?（i=0;i??????{
???????max=A[k*n+i];
???????A[k*n+i]=A[r*n+i];
???????A[r*n+i]=max;
??????}
??????max=b[k];????????????????????/*change?array:b[k]&b[r]?????*/
??????b[k]=b[r];
??????b[r]=max;
??????for?（i=k+1;i???{
????for?（j=k+1;j????????A[i*n+j]-=A[i*n+k]*A[k*n+j]/A[k*n+k];
????b[i]-=A[i*n+k]*b[k]/A[k*n+k];
???}
?????}

for?（i=n-1;i>=0;x[i]/=A[i*n+i]i--）
?????for?（j=i+1x[i]=b[i];jx[i]-=A[i*n+j]*x[j];
}

?屬性????????????大小?????日期????時間???名稱
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?????文件?????837120??2009-06-27?21:24??數值計算\數值計算課程設計報告.doc

?????文件???????2698??2009-06-11?09:36??數值計算\數值分析程序代碼\經典四階龍格庫塔法.c

?????文件????????966??2009-06-11?10:00??數值計算\數值分析程序代碼\弦割法.c

?????文件???????2489??2009-06-11?12:15??數值計算\數值分析程序代碼\M次多項式曲線擬合.c

?????文件???????1316??2009-06-11?21:02??數值計算\數值分析程序代碼\高斯列主元.c

?????文件???????2294??2009-06-11?21:26??數值計算\數值分析程序代碼\用牛頓法解非線性方程組.c

?????文件???????2383??2009-06-11?22:08??數值計算\數值分析程序代碼\龍貝格求積分算法.c

?????文件???????1019??2009-06-11?22:15??數值計算\數值分析程序代碼\三次樣條插值.c

?????文件???????1146??2009-06-11?22:55??數值計算\數值分析程序代碼\雅克比迭代.c

?????文件????????801??2009-06-19?13:58??數值計算\數值分析程序代碼\泰勒公式.c

?????文件????????367??2009-06-19?14:17??數值計算\數值分析程序代碼\復合辛普森.c

?????文件????????624??2009-06-28?05:32??數值計算\數值分析程序代碼\二分法.c

?????目錄??????????0??2011-04-09?20:22??數值計算\數值分析程序代碼

?????目錄??????????0??2011-04-09?20:21??數值計算

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