change size[ 3 1] to [3 25]

Question

Haiwen Sun 2020-10-28

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/628463-change-size-3-1-to-3-25

回答： Sourabh Kondapaka 2020-11-6

a = [1 4 -2];

strColors = {'-r', '-g', '-b'};

for k=1:length(a)

LabFc3 = @(x)sin((a(k)/2)*pi*x).*(a(k)*x.^2+3);

fplot(LabFc3,[-8 8],strColors{k});

funcOut(k,:) = LabFc3(a(k)); linspace(-8,randi([0,8],1,1),25);

hold on;

end

This is my code here. In my instruction, it only gives me [1 4 -2] these three values. Everything is fine besides the funcOut size is [3 1], it requires [3 25]. How could I fix this?

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。

Answer 1

Sourabh Kondapaka 2020-11-6

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/628463-change-size-3-1-to-3-25#answer_535955

在 MATLAB Online 中打开

Hi Haiwen Sun,

If we pre-allocate funcOut matrix of size 3 x 25, we can get the output you are trying to achieve. This is happening because data is being over-written.

Consider the following code:

a = [1 4 -2]; 
strColors = {'-r', '-g', '-b'}; 
% Pre allocating a matrix of size 3x25 
funcOut = zeros(3,25);
for k=1:length(a)
    LabFc3 = @(x)sin((a(k)/2)*pi*x).*(a(k)*x.^2+3);
    fplot(LabFc3,[-8 8],strColors{k});
    funcOut(k,:) = LabFc3(a(k)); linspace(-8,randi([0,8],1,1),25);
    hold on;
end