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• # Lesson 4

Posted by on May 22, 2023 at 12:24 pm

Hello there:I downloaded three different codes in python, and noticed, they are done based on “free vibrations” and “forced vibrations”. and “non-linear”. My first question is regarding the codes. The activity sais I should submit the script of three from the five different problems suggested. I am assuming I must submit the script corresponding to “free vibrations” with the respective parameters modified. However, I am confused, since in the script called “SMD-free-graphs”, which i believe it is the one for free vibrations, does not have the parameters I am given in the problems. Is that the script I should use? My second question is, what does the parameter “y dot” mean here?

Thanks beforhand.

2 Members · 3 Replies
• 3 Replies
• ### Chennakesava

Member
May 23, 2023 at 2:52 pm

Hi,

1. Yes, you should adapt the “SMD-free-graphs.py” script and modify the parameters as per those in the questions you choose. Some parameters are hard-coded. You need to identify them and modify them accordingly.

2. y dot is the first derivative of y. So, y dot is velocity.

• ### Juan Carlos

Member
May 24, 2023 at 3:23 pm

Dear Dr. Chennakesava:

Thanks for the reply. My second question was regarding where y_dot (the first derivative) belong in the script but I noticed, in the script, it goes within the vector defined “y0”. My follow-up question is, since we are dealing with second order equations, I have to convert each of the equations I want to work on, into two first order equations, so that I can use odeint, am I right? Any hints?

Thanks beforehand

• ### Chennakesava

Member
June 7, 2023 at 8:09 am

Yes, that’s correct!

Since our ODEs are second-order, we have to convert them into two first-order ODEs so we can use “odeint” function which supports only first-order equations.