XProfan

Window Title "Interpolation to Aitken-Neville"
' Q: Wikipedia, div. professional journals
Window Style 24
Window 0,0 - %maxx,%maxy
print " The Interpolationsformel of Aitken and Neville is dann"
print " particularly efficient, if from about twice so many Stütz-"
print " to put only few values rasch interpolation go should,"
print " without that the Interpolationspolynom self demand is."
print
declare x![25],y![25],n&,i&,a!,b!,s!
declare p![25,25],k&,p1!,p2!
print " Eingabeteil:"
print " amount Wertepaare [max. 25]: ";:input n&

whileloop 0,n&-1:i&=&Loop

    print int(i&+1);". Wertepaar: x = ";:input x![i&]
    print         "              y = ";:input y![i&]

endwhile

print
print " area, in the y-values interpolation go should:"
print " From: ";:input a!
print " To: ";:input b!
print " Schrittweite: ";:input s!
print
print " Berechnung Start with [Button]!"
waitinput
cls
print
print " Result:"
print "          x                        y    "
print "-----------------------------------------------"
k&=0

whileloop 0,n&-1:i&=&Loop

    p![i&,k&]=y![i&]

endwhile

Naechstes:

Whileloop 0,n&-2:k&=&Loop

    whileloop k&+1,n&-1:i&=&Loop

        p1!=(a!-x![i&-k&-1])*p![i&,k&]-(a!-x![i&])*p![i&-1,k&]
        p2!=x![i&]-x![i&-k&-1]
        p![i&,k&+1]=p1!/p2!

    endwhile

endwhile

print a!,p![n&-1,n&-1]'= Results

if a!<b!:a!=a!+s!:goto "Naechstes":endif

    Print "OK.";:waitinput:End