the code doesn't update the values
显示 更早的评论
anyone can help with this matlab code it doesn't update the values of p and t
n=1
while n<20
p=10^((30.59051-8.2*log10(t))+(0.0024804*t)-(3142.31/t))
t=314+((6.324-p)/(6.66*(10^-4)*101.32));
n=n+1;
end
采纳的回答
Of course it does, it just doesn't do what you think it should, apparently...
ADDENDUM-
If you're also expecting to build vectors of t and p, then you need to tell Matlab that, too...
Several problems here...
- First, t is undefined at the beginning of the loop
What is it to be to begin with. If you start w/ t=0, then
log10(0)-->-Inf
and you divide by it later on, too. Solve those issues and you'll at least get some numeric output.
Before the loop add
p=zeros(20,1); t=p; % preallocate
Inside the loop then
p=...
needs must become
p(n)=...;
and likewise for t to save the individual values.
4 个评论
ibrahim
2014-5-2
Your equations are very unstable--in particular t oscillates wildly and then essentially "blows up". Observe first few iterations...
>> t=300;p=0;
>> n=1; disp([n t p])
while n<6
p=10^((30.59051-8.2*log10(t))+(0.0024804*t)-(3142.31/t));
t=314+((6.324-p)/(6.66*(10^-4)*101.32));
n=n+1;
disp([n t p])
end
1 300 0
2.0000 355.3940 3.5308
3.0000 -360.1268 51.8135
1.0e+18 *
0.0000 -3.4568 + 2.5115i 0.2333 - 0.1695i
5.0000 407.7179 0
1.0e+03 *
0.0060 -4.1697 0.3089
>>
This isn't a Matlab problem; it's in the equations as written...
ibrahim
2014-5-3
dpb
2014-5-3
So what are the equations intended to represent and where did you obtain them? Looks like a correlation of some sort; are you sure you've coded them correctly and are using proper units to scale t,p initial values within defined range of the correlation is so?
更多回答（1 个）
Azzi Abdelmalek
2014-5-1
0 个投票
You need to initialize your variable t
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