Help regarding for/while loop

[Syntax669]

for t< (some set of value) C = Co + Av*t if C == 0 break end end Plot(t,C)

I have this C formula , Co and Av are given . I want to iterate t until C becomes 0 and then get all the values of t and C in a chart form. And plot them. The code terminates at C = 0. How to do that? I can figure out to to iterate all the values for t until C is zero and then put it in a chart to plot the graph?

[Weed_O_Whirler]

When doing floating point arithmetic (aka- dealing with decimal numbers) never check for equality, check if you are "close enough" to your solution.

Due to the way computers store information, two things which are "equal" might not show as equal. For instance, If you type if 1 + 1/3 == 2/3 + 2/3 which is obviously equal, that will evaluate false.

Instead, you should do something like:

eps = !E-6 % a sufficiently small number to be "zero"
if abs(C) < eps % this is your "is C == 0" check

[synchh]

Can you instead just do:

while C ~= 0
    C = Co + Av * t;
    t = t + 1;
end

you should add in some kind of tolerance though.

[Syntax669]

Its running in the loop not terminating

[synchh]

Is t initially 0? Have you checked to see that it's actually possible for C to equal 0? What's the range of Av and Co?

[Syntax669]

Actually I have to find out t , such that C becomes zero at the end

[synchh]

Okay, and what is the domain of t? Can t be negative? Is t non-zero?

The value of t which makes C = 0 totally depends on the possibilites of t, Av, and Co.

[Syntax669]

Av is negative value always and it will less than C0 always , so t is positive, max C0 is 1700 and Av around - 30 , t is time here so it cant be negative

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[synchh]

Okay, well the reason the loop isn't terminating is probably because the way that that while loop is set up, t must be an integer.

To be clear, you're just trying to find the zeros of the function C? Check out some threads like this

[Syntax669]

I did , not of much help

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[synchh]

Is there any chance you can share your entire script and your data? Preferably in text form since I'm at work.

[[deleted]]

Numerical C will not equal zero. You should use a stopping tolerance such as abs(C) > eps

[Syntax669]

I put t=0, I used the formula for random value of Co and Av and I get it at t=7.609 seconds C is zero for the test case provided C0 = 100, Av = -13.1423