Is this correct?
显示 更早的评论
Use loops to compute and plot (not animated)the following piecewise function for -15<=x<=15 .
F(x)={5x, x<0
{x^2, 0<=x<2
{ 2lnx, x>=2
My code:
x=-15:15;
if x<0;
5*x;
elseif x>=0 & x<2
y=x^2;
else x>=2;
y=2*log(x);
end
plot(x,y)
4 个评论
Allison Sims
2022-7-18
M.B
2022-7-18
Check your variable names and indexation.
Chunru
2022-7-18
Although the code is not doing what it intends to, the code can be run and MATLAB only gives a warning message (orange color).
采纳的回答
x=-15:15;
y = zeros(size(x));
% This is more MATLAB way
idx = x<0;
y(idx) = 5 * x(idx);
idx = x>=0 & x<2;
y(idx) =x(idx).^2;
idx = x>=2;
y(idx) = 2*log(x(idx));
plot(x,y)
% This is more conventional way (some othter programming language)
x=-15:15;
y = zeros(size(x));
for i=1:length(x)
if x(i)<0
y(i) = 5 * x(i);
elseif x(i)>=0 & x(i)<2
y(i) =x(i).^2;
elseif x(i)>=2;
y(i) = 2*log(x(i));
end
end
figure
plot(x,y)
更多回答（1 个）
x = -15:1:15;% init x
y = nan*x;% init y to be of same size as x
for index = -15:15;
if index<0;
y(index+16) = 5*index;
elseif index>=0 & index<2
y(index+16) = index^2;
else index>=2;
y(index+16) = 2*log(index);
end
end
plot(x,y)
2 个评论
Allison Sims
2022-7-18
Chunru
2022-7-18
The "index" is the loop variable the code uses and it need to be added with 16 in order to become array index (which is 1,2,...31). It's working code, but it may be further improved.
类别
在 帮助中心 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 
