1 files changed, 30 insertions, 0 deletions
diff --git a/50/DEPENDENCIES/lagrangefundamentalpoly.sci b/50/DEPENDENCIES/lagrangefundamentalpoly.sci
new file mode 100755
index 000000000..b55a42ff6
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+++ b/50/DEPENDENCIES/lagrangefundamentalpoly.sci
@@ -0,0 +1,30 @@
+function P2=lagrangefundamentalpoly(x,f,n)
+    [nrx,ncx]=size(x)
+    [nrf,ncf]=size(f)
+if ((nrx<>1)|(nrf<>1)) then
+	error('x or f, or both, not column vector(s)');
+	abort;
+end;
+if ((ncx<>ncf)) then
+	error('x and f are not of the same length');
+	abort;
+end;
+
+ X=poly(0,"X");
+L=zeros(n);
+
+P2=0;
+for i=1:n+1
+    L(i)=1;
+   for j=1:n+1
+       if  i~=j then
+               L(i)=L(i)*(X-x(j))/(x(i)-x(j))
+       end;
+end;
+P2=P2+L(i)*f(i); 
+end;
+
+
+endfunction
+
+