資源簡介
拉格朗日插值法程序
n=size(pointx,2);
L=ones(n,size(x,2));
if (size(pointx,2)~=size(pointy,2))
fprintf(1,'\nERROR!\nPOINTX and POINTY must have the same number of elements\n');
y=NaN;
else
for i=1:n
for j=1:n
if (i~=j)
L(i,:)=L(i,:).*(x-pointx(j))/(pointx(i)-pointx(j));
end
end
end
y=0;
for i=1:n
y=y+pointy(i)*L(i,:);
end
end
代碼片段和文件信息
function?y=lagrange（xpointxpointy）
%
%LAGRANGE???approx?a?point-defined?function?using?the?Lagrange?polynomial?interpolation
%
%??????LAGRANGE（XPOINTXPOINTY）?approx?the?function?definited?by?the?points:
%??????P1=（POINTX（1）POINTY（1））?P2=（POINTX（2）POINTY（2））?...?PN（POINTX（N）POINTY（N））
%??????and?calculate?it?in?each?elements?of?X
%
%??????If?POINTX?and?POINTY?have?different?number?of?elements?the?function?will?return?the?NaN?value
%
%??????function?wrote?by:?Calzino
%??????7-oct-2001
%
n=size（pointx2）;
L=ones（nsize（x2））;
if?（size（pointx2）~=size（pointy2））
???fprintf（1‘\nERROR!\nPOINTX?and?POINTY?must?have?the?same?number?of?elements\n‘）;
???y=NaN;
else
???for?i=1:n
??????for?j=1:n
?????????if?（i~=j）
????????????L（i:）=L（i:）.*（x-pointx（j））/（pointx（i）-pointx（j））;
?????????end
??????end
???end
???y=0;
???for?i=1:n
??????y=y+pointy（i）*L（i:）;
???end
end
?屬性????????????大小?????日期????時間???名稱
-----------?---------??----------?-----??----
?????文件?????????908??2001-10-07?23:08??lagrange.m
- 上一篇：最速下降法matlab
- 下一篇：頻譜圖matlab函數
評論
共有 條評論
川公網安備 51152502000135號