@jcp Implementing mathematical formulae tends to be a high-investment low-reward thing, speaking from experience as a volunteer here. If you can try (not necessarily succeed) to write some of the code to do it yourself, that helps a lot since it gives people a jumping off point. Also get some pictures of "expected results" in there. That makes it more interesting for people.

Might also be good to describe why you want to do it, since having a real world application is generally more interesting than a bunch of math -- and I say this as a scientist who often prefers the math to the science

In general, though, to get good interest add pictures

They give something to grab the eye and they give an easy way for someone to know if they wrote the code correctly

@jcp Well, your code still involves TraditionalForm, I mean the h2[j, ρ[t], r[t]] := -(1/900) E^-r(t) (E^r(t) - 1) … part.

Also, the output seems to be generated from a system of ODE that's not the same as the one in the input?

To be honest, I think your question is a bit… chaotic. The target of the question is not clear enough. You've showed your trial, but as already mentioned in the comment, it's incorrect, in principle. (The system is overdetermined. ) So we can't even try to fix it.

Thanks for your comments guys! I rewrote and copied the equations again applying InputForm[] to the equations before copying them. I think the output and input ODES are the same, again I just copied htem directly. I think the FullySimplify call modified the output.

I understand the ODE system is overdetermined so may not be the best way to solve this problem. perhaps this just calls for a different question altogether. One way I can think of algorithmically to solve this problem is guess a parametrized path connected the two points in phase space, and then modify it, see if the action decreases, then modify it again. An algorithm for the same has been described here: onlinelibrary.wiley.com/doi/abs/10.1002/cpa.20238

I wouldn't know how to start to implement it in Mathematica or even make an attempt at a solution at this stage, and this might call for a new question altogether

Someone who has 11.0 handy, please check if GraphData["C3+K1,3"] returns anything ...

running 11.3 returns a a triangle and a tree

@halirutan, @b3m2a1, and everybody else, thanks for contributing to my coffee hab... er, small fund drive! I'm still not fully settled, and my computer is really starting to show signs of its being well-used.

even the little bits are still a great help

Hello

What other options of tracing a command do I have besides "Trace"?

I am using Trace@<somefunction> and it returns:

{}

????

try Trace@StackComplete@<somefunction>

if <somefunction> is a built in you might not be able to see much though

Nice, thank you, this worked!

It's solved

:)

Ok the errors are getting very obscure now:

GlobalNull$20432::shdw: Symbol Null$20432 appears in multiple contexts {Global,System}; definitions in context Global may shadow or be shadowed by other definitions.

I understand what it means, but I have not defined any such symbol anywhere..

So in some sense I don't understand what it means

:D

@JasonB. hey, for some reason I had missed this chat message. You can e-mail me at StringReplace["kovzhfivluurtfirmt@tnzro.xln", Thread[Alphabet[] -> Reverse[Alphabet[]]]] if you're still interested in discussing this.

@Szabolcs I think you were a proponent of the Iterator idea, looks like it's about to get discussed ^

@development-oriented-people I'm trying to abstract the core package framework out of my BTools package so it can be used in a more light-weight way (and so I can more cleanly extend and work with it).

Are there any features people would like to see in such a thing?

The idea is to make it easy to develop packages where all of the context handling, package layout, PacletInfo.m setup, etc. is done for you

Plus optional features like easy autocompletions, syntax coloring, etc.

@1010011010 Could be that there is a superfluous , somewhere in a Module variable list (which would cause a Null variable to be declared)

All of this stuff is already in the package, but I want to make it easier to work with and add features that people might find usefull

!! That explains the jump in my reputation

I got some too :)

How do you know that you should use List there?

I can see that in some examples but I wonder why don't they clearly say that at the beginning.

@anhnha Perhaps it could have been clearer, but if you look at the usage message for Graphics[], the syntax given is Graphics[primitives, options], and Disk[] is manifestly not an option (which should be of the form option -> value or option :> value).

@J.M.willbebacksoon yeah but how does that relate to the use of List or not?

Well, that eliminates the use of Graphics[GrayLevel[0.3], Disk[]]. As I said, things could perhaps have been clearer.

On the other hand, primitives implies a collection of things, and usually those are represented as a list.

In any event, both Graphics[Disk[]] and Graphics[{Disk[]}] work, so you would only need a list if you have more than one primitive or directive to put in.