why i get the undefined variable message?

2019 10 15
1 个回答
回答已采纳
更新时间：2019 10 15
3 次查看（30 天）

0 个投票

I have this code for QAM:
p=(sign(randn(N,1))+2)/2;
for i=1:length(p/2)-1
if p(i)==0 && p(i+1)==0
s(i)=1+1i;
elseif p(i)==0 && p(i+1)==1
s(i)=1-1i;
elseif p(i)==1 && p(i+1)==1
s(i)=-1-1i;
elseif p(i)==1 && p(i+1)==0
s(i)=-1+1i;
end
end
scatterplot(s);
and when i try to run this thing i get the message :undefined variable 's'.
Do you know what should i do to fix this.I dont think its a code fault but its a matlab problem .
Thank you.

1 个评论
显示 -1更早的评论 隐藏 -1更早的评论

Adam Danz
Adam Danz 2019-10-15
编辑：Adam Danz 2019-10-15
If none of your conditions are met, s will never be defined. So when you get to the last line of your code, s is undefined.
The problem is that none of your conditions are being met and 's' has no default value for when that happens.

请先登录，再进行评论。

请先登录，再回答此问题。

 采纳的回答

KALYAN ACHARJYA
KALYAN ACHARJYA 2019-10-15
编辑：KALYAN ACHARJYA 2019-10-15

0 个投票

and when i try to run this thing i get the message :undefined variable 's'.
First:
Because you did not defined N
Second for S, considering N=10 here, whatever you choose the value of N, p reflects numbers of 0.5 and 1.5
Also
p =
0.5000
1.5000
1.5000
0.5000
1.5000
0.5000
0.5000
1.5000
1.5000
1.5000
Neither the any if condition is true for p value, so "s" value didnot get assign. Beacuse p(i) and p(i+1) ==0 or 1 is not true for any case

更多回答（0 个）

类别

在 帮助中心 和 File Exchange 中查找有关 Introduction to Installation and Licensing 的更多信息

标签

Community Treasure Hunt

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

Start Hunting!

Translated by