def func(x,y,X,infor=True):
list2=[y[0]] # 差商表的对角线的第一个元素始终是y0
count=1
while(True):
if len(y)>1:
list=[] # 空列表用来保存,每次计算后差商表的行
for i in range(len(y)-1):
n=x[i+count]-x[i]
m=y[i+1]-y[i]
l=m/n
list.append(l)
list2.append(list[0]) # list2用来记录差商表的对角线元素,每计算一次,取行的第一个元素
count += 1
y = list
else:
break
if infor: # 判断是否要继续计算,结果
W=0
for i in range(len(list2)):
if i==0:
w=list2[i]
else:
w = list2[i]
for j in range(i):
w*=(X-x[j])
W+=w
print('牛顿插值:', W)
return '牛顿差商表对角线列:%s' %list2
ret=func([0.32, 0.34, 0.36],[0.314567, 0.333487, 0.352274],'',infor=False)
print(ret)
ret=func([0.32, 0.34, 0.36],[0.314567, 0.333487, 0.352274],0.3367)
print(ret)
运行结果:
