Info

This question is closed. Reopen it to edit or answer.

need help with if, else use

6 views (last 30 days)
ASH HUSSAIN
ASH HUSSAIN on 14 Oct 2011
Closed: MATLAB Answer Bot on 20 Aug 2021
hi
i want to clculate Cp for different temperatures, if it is in the limit Ts(j)<=750; then should claculate Cp as
Cp=0.459389e3+(0.927605*Ts(j))+(-0.892667e-2*Ts(j)^2)+(0.427170e-4*Ts(j)^3)+(-0.823237e-7*Ts(j)^4)+(0.617737e-10*Ts(j)^5)+(-0.885174e-14*Ts(j)^6);
and if it is between 750 and 900 ie. Ts(j)>=750; Ts(j)<=900; then should claculate Cp as
Cp=0.960497e4+(0.311055e2*Ts(j))+(-0.821919e-1*Ts(j)^2)+(-0.9966420e-5*Ts(j)^3)+(-0.291067e-8*Ts(j)^4)+(0.166675e-9*Ts(j)^5)+(-0.112167e-12*Ts(j)^6);
and finaly if Ts(j)>=900; then should claculate Cp as
Cp=0.595783e3+(0.809290*Ts(j))+(-0.172302e-2*Ts(j)^2)+(0.113957e-5*Ts(j)^3)+(-0.946037e-10*Ts(j)^4)+(-0.762604e-13*Ts(j)^5);
% For conductivity "k" at different temp ranges;
if Ts(j)<=800;% c
k=0.519059e2+(-0.369417e-3*Ts(j))+(-0.768098e-4*Ts(j)^2)+(-0.811310e-8*Ts(j)^3)+(0.212134e-9*Ts(j)^4)+(-0.180744e-12*Ts(j)^5);
if Ts(j)>=800; % c
k=0.302492e2+(-0.155686e-1*Ts(j))+(0.144759e-4*Ts(j)^2)+(-0.982726e-8*Ts(j)^3)+(0.159948e-10*Ts(j)^4)+(-0.96461e-14*Ts(j)^5)+(0.148732e-17*Ts(j)^6);
and then i want to clculate M=...... below
roL=7800; % density of load mild steel kg/m3.
dx=1:25;
dt=0:5:60;
M=(roL*Cp*dx^2)/(k*dt);
please can somebody help me writing this in matlab.
thanks

Answers (2)

Sean de Wolski
Sean de Wolski on 14 Oct 2011
There are numerous questions equaivalent to yours. Start Here: Answers:Search:if+elseif+else

Florin Neacsu
Florin Neacsu on 14 Oct 2011
Something like:
if Ts(j)<=750
Cp=0.459389e3+(0.927605*Ts(j))+(-0.892667e-2*Ts(j)^2)+(0.427170e-4*Ts(j)^3)+(-0.823237e-7*Ts(j)^4)+(0.617737e-10*Ts(j)^5)+(-0.885174e-14*Ts(j)^6);
elseif Ts(j)<=900
Cp=0.960497e4+(0.311055e2*Ts(j))+(-0.821919e-1*Ts(j)^2)+(-0.9966420e-5*Ts(j)^3)+(-0.291067e-8*Ts(j)^4)+(0.166675e-9*Ts(j)^5)+(-0.112167e-12*Ts(j)^6);
else Ts(j)>900
Cp=0.595783e3+(0.809290*Ts(j))+(-0.172302e-2*Ts(j)^2)+(0.113957e-5*Ts(j)^3)+(-0.946037e-10*Ts(j)^4)+(-0.762604e-13*Ts(j)^5)
end
To make it clear
if T<=750
Cp=...
elseif T<=900
Cp=...
else
Cp=...
end
Btw, you need to choose the exact Cp for T=900 (right now you have 2 different definitions).
Regards, Florin

Tags

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!