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[BASIC HELP] CAS.fsolve problem [Solved]
03-23-2019, 08:08 PM
Post: #6
RE: [BASIC HELP] CAS.fsolve problem
Thank you! You solved my problem. I spent some time trying to make the code work.


(03-22-2019 04:09 PM)roadrunner Wrote:  You have to send CAS commands as a string and then EVAL the string and the variable you are solving for can't be local. Make those two changes and you get:

PHP Code:
EXPORT Pws(T)
BEGIN
 T
:=T+273.15;
 
LOCAL C1,C2,C3,C4,C5,C6,C7;
 
LOCAL Ps;

 
C1:=-5.6745359*10^3;
 
C2 := 6.3925247*10;
 
C3 := −9.6778430/10^(3);
 
C4 := 6.2215701/10^(7);
 
C5 := 2.0747825/10^(9);
 
C6 := −9.4840240/10^(13);
 
C7 := 4.1635019*10;
 
Ps:=CAS.EVAL("fsolve(C1/T+C2+C3*T+C4*T^2+C5*T^3+C6*T^4+C7*ln(T)=ln(P),P,1000)");
 PRINT(
"Ps="+Ps);
 RETURN 
Ps;
END

which returns an answer.


edit: Hmm, it appears you dont' have to EVAL the string because this:

Ps:=CAS("fsolve(C1/T+C2+C3*T+C4*T^2+C5*T^3+C6*T^4+C7*ln(T)=ln(P),P,1000)");

also works.

-road
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Messages In This Thread
RE: [BASIC HELP] CAS.fsolve problem - Ziz - 03-23-2019 08:08 PM
RE: [BASIC HELP] CAS.fsolve problem - DrD - 03-22-2019, 04:35 PM
RE: [BASIC HELP] CAS.fsolve problem - Ziz - 03-23-2019, 08:04 PM



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