# I don't know what is wrong with my code when recreating a table

1 view (last 30 days)
Sarah Kneer on 12 Nov 2020
Commented: Peter Perkins on 19 Nov 2020
There's this table I need to create, in which, depending on the time(t), the value of Clo and Met changes. My code is:
t = 0:0.5:24;
for i = 0:0.5:24
if t(i)>=0 && t(i)<8
Clo = 3;
Met = 0.4;
end
if t(i)>=8 && t(i)<12
Clo = 1;
Met = 1;
elseif t(i)>=12 && t(i)<17
Clo = 0.5;
Met = 1.6;
elseif t(i)>=17 && t(i)<22
Clo = 1;
Met = 0.9;
elseif t(i)>=22 && t(i)<24
Clo = 2.5;
Met = 0.4;
else
plot(t,Clo,'g');
xlabel ('Time (hours)');
ylabel ('Clo');
end
end

Subhadeep Koley on 12 Nov 2020
loop indices must be positive integers or logical values. In your code, you're trying to use fraction values as index. Also, your plot command is inside an else branch. The below modifications might help.
t = 0:0.5:24;
Clo = zeros(size(t));
Met = zeros(size(t));
for idx = 1:numel(t)
if t(idx)>=0 && t(idx)<8
Clo(idx) = 3;
Met(idx) = 0.4;
elseif t(idx)>=8 && t(idx)<12
Clo(idx) = 1;
Met(idx) = 1;
elseif t(idx)>=12 && t(idx)<17
Clo(idx) = 0.5;
Met(idx) = 1.6;
elseif t(idx)>=17 && t(idx)<22
Clo(idx) = 1;
Met(idx) = 0.9;
elseif t(idx)>=22 && t(idx)<=24
Clo(idx) = 2.5;
Met(idx) = 0.4;
end
end
plot(t, Clo,'g')
xlabel ('Time (hours)')
ylabel ('Clo')
figure
plot(t, Met,'r')
xlabel ('Time (hours)')
ylabel ('Met')

Stephen Cobeldick on 12 Nov 2020
Works for me, copied verbatim:
t = 0:0.5:24;
Clo = zeros(size(t));
Met = zeros(size(t));
for idx = 1:numel(t)
if t(idx)>=0 && t(idx)<8
Clo(idx) = 3;
Met(idx) = 0.4;
elseif t(idx)>=8 && t(idx)<12
Clo(idx) = 1;
Met(idx) = 1;
elseif t(idx)>=12 && t(idx)<17
Clo(idx) = 0.5;
Met(idx) = 1.6;
elseif t(idx)>=17 && t(idx)<22
Clo(idx) = 1;
Met(idx) = 0.9;
elseif t(idx)>=22 && t(idx)<=24
Clo(idx) = 2.5;
Met(idx) = 0.4;
end
end
plot(t, Clo,'g')
xlabel ('Time (hours)')
ylabel ('Clo')
figure
plot(t, Met,'r')
xlabel ('Time (hours)')
ylabel ('Met')
Sarah Kneer on 12 Nov 2020
I got it know, I missed the (i) after Clo and Met. Thanks.
Peter Perkins on 19 Nov 2020
It's also worth noting that the loop in this code is unnecessary:
t = 0:0.5:24;
Clo = zeros(size(t));
Met = zeros(size(t));
i = t>=0 & t<8
Clo(i) = 3;
Met(i) = 0.4;
i = t>=8 && t<12
Clo(i) = 1;
Met(i) = 1;
i = t>=12 && t<17
Clo(i) = 0.5;
Met(i) = 1.6;
i = t>=17 && t<22
Clo(i) = 1;
Met(i) = 0.9;
i = t>=22 && t<=24
Clo(i) = 2.5;
Met(i) = 0.4;