Loop-can you suggest another way to write the following loop?

2 次查看（过去 30 天）

B 2015-3-19

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/183931-loop-can-you-suggest-another-way-to-write-the-following-loop

评论： Star Strider 2015-3-19

Hello,

I'm trying to create an m.file to evaluate the polynomial P5(x)=a0+a1x+a2x^2+a3*x^3+a4*x^4+a5*x^5, where a is a vector [-120 274 -225 85 -15 1]. The following code is working but I'm a beginner and always like to know how ppl with experience might write the code. Many thanks for your cooperation so far..

---------------------------------------------------------------------------------------------------------

%polyfive.m syms x a=[-120 274 -225 85 -15 1]; p5old=0

for m=1:length(a) n=m-1; p5new=p5old+a(m)*x^(n); p5old=p5new; m=m+1 ; end disp(p5new)

0 个评论
显示 -2更早的评论隐藏 -2更早的评论

请先登录，再进行评论。

请先登录，再回答此问题。

采纳的回答

Star Strider 2015-3-19

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/183931-loop-can-you-suggest-another-way-to-write-the-following-loop#answer_171897

在 MATLAB Online 中打开

I wouldn’t write a loop at all. I would use polyval:

a=[-120 274 -225 85 -15 1];
x = linspace(0, 6);
y = polyval(fliplr(a), x);
figure(1)
plot(x, y)
grid

4 个评论
显示 2更早的评论隐藏 2更早的评论

B 2015-3-19

Thanks a lot :)

Star Strider 2015-3-19

My pleasure!

请先登录，再进行评论。

类别

MATLAB Language Fundamentals Loops and Conditional Statements

在 Help Center 和 File Exchange 中查找有关 Loops and Conditional Statements 的更多信息

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by