Question on odesolve

[ptc-4735478]

I am sure this question has been asked 1 million times, I tried to look up the forum, but I still cannot spot my error.

I was practicing the odesolve function...but I do not know what mistake I made...

1st file is just a copy of a mathcad file posted by valery. I just put in everything again and see if I understand the logic...but then I have an error of

This value must be a function, but has the form: Unitless.

2nd file is just 1 ode, but it says I have to many initial condition, when I delete one it says variable not defined.

Please help

[Werner_E · Accepted solution]

In 1_spring you had two errors:

1) the syntax for odesolve is different in Mathcad15 and below compared to Prime. Look it up in the help. Obviously your template was a Prime file

2) in your first equation you had y(t) instead of y1(t)

[ptc-4735478]

Thank Werner!

I finally just retype my other copy cat worksheet and it works..I still do not know what mistake I made in the beginning...but it is now all working fine..

Thanks

[Werner_E]

I spotted some errors in that file:

1) Your fourth equation, denominator of second summand has 3(t) instead of y3(t)

2) The last initial condition has y3' instead of x3'

3) End value 17 seems to be too high for the values you had chosen, set t.e down to 7 and it converges

The way you have set it up the ode solve block is called for every frame of your animation. So it will take a very long time for the 500 frames to calculate.

Its much quicker if you let solve to t.e once and then define a range variable t:=0,0.1..t1