How to define a variable as a condition of other variables
11 次查看(过去 30 天)
显示 更早的评论
Hi there, I am working on a project for an environmental science class where I need to plot the change in temperature as a function of the change in the solar constant from 1000wm-2 to 2000wm-2. The equation I need to use is TSI=r^2*Stefan-Boltzmann constnat*T^4 / L^2, where I know the values of r, SB constant, and L, but I'm not sure how to write the program such that it calculates a new temperature for each TSI value between 1000-2000, if that makes sense. I have an intial condition for the temperature as well. I assume I need a for loop somewhere, but I'm not sure how to start writing the equation for finding each temperature.
Thanks very much.
2 个评论
Cris LaPierre
2022-3-16
What have you tried so far? You'll find the community happy to help you fix your code, but more hesitant to code your assignment for you.
采纳的回答
Torsten
2022-3-16
编辑:Torsten
2022-3-16
dTSI = r^2*SBC*4*T^3*dT/L^2
dT = dTSI*L^2/(r^2*SBC*4*T^3)
dT/dTSI = L^2/(r^2*SBC*4*T^3)
Thus in MATLAB:
r = ...;
SBC = ...;
L = ...;
TSI = 1000:1:2000;
T = (TSI*L^2/(r^2*SBC)).^0.25
dTdTSI = L^2./(r^2*SBC*4*T.^3)
plot(TSI,dTdTSI)
I'm still not 100% certain if this is really what you are told to plot, but I guess it's correct.
0 个评论
更多回答(2 个)
Enrico Gambini
2022-3-16
编辑:Enrico Gambini
2022-3-16
Hi.
Generally matlab "doesn't like" for loops like other programming languages. That's because in most of the cases there is the possibility to indicize an array in a simpler (and faster) way.
Hence, for your specific problem I propose:
r=input("Insert the value of r:\n");
L=input("Insert the value of L:\n");
Sb_const=input("Insert the value of Stefann-Boltzmann constant :\n");
TSI=[1000:2000];
T=(TSI*L^2/(r^2*Sb_const)).^(1/4); %I inverted the formula and it is computing the Temperature at an interval of 1 W/m2 between 1000 and 2000
plot(TSI,T); %plot TSI vs T
0 个评论
另请参阅
类别
在 Help Center 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!