@Joe Riel Sigh. I'm never satisfied with using satisfies with a predicate that is pure (albeit parametrized) syntactic type checking. It always leaves me feeling there's gotta be a smoother way.

Acer wrote:

> depnames := indets(expr,And(And(name,Non(constant)),
> 'satisfies'(u->depends(expr,u))));

It seems like such a fundamental concept that it's surprising that there isn't a more primitive typespec for that. I suspect that in the majority of cases where one calls indets(expr, name) that the above is what one really wants. I've found a few bugs in library code that probably would've been avoided if there had been a primitive typespec for the concept. (One I recall involved fsolve(Int(..., [x=..., y=...]), ...) where it complained about x and y not being solved for. That's fixed in Maple 17.) There are the types ?type,dependent and ?type,freeof, but they are types which are applied to an expression, not to the names within the expression.

Acer wrote:

> depnames := indets(expr,And(And(name,Non(constant)),
> 'satisfies'(u->depends(expr,u))));

It seems like such a fundamental concept that it's surprising that there isn't a more primitive typespec for that. I suspect that in the majority of cases where one calls indets(expr, name) that the above is what one really wants. I've found a few bugs in library code that probably would've been avoided if there had been a primitive typespec for the concept. (One I recall involved fsolve(Int(..., [x=..., y=...]), ...) where it complained about x and y not being solved for. That's fixed in Maple 17.) There are the types ?type,dependent and ?type,freeof, but they are types which are applied to an expression, not to the names within the expression.

Sheesh. It sure is easy to transcribe exp^-s as exp(-s) using only the "naked eye" on someone else's 2D input. So please post code-to-be-debugged in a form that can be downloaded or cut-and-pasted.

I have transcribed and executed your code without error, obtaining the plot. Try putting a restart at the beginning. If it still doesn't work, upload your entire worksheet.

@wb_jerry Okay, then the problem is almost certainly solvable. I ask again: Is a floating-point solution acceptable?

What do you mean by "anyway"? Didn't I help you?

@wb_jerry Okay, then the problem is almost certainly solvable. I ask again: Is a floating-point solution acceptable?

What do you mean by "anyway"? Didn't I help you?

@JamesK Note that it is only the long display labels that make the plot look messy. There is no problem with the internal representation of the Graph. I am about to post an update that deals with this.

@JamesK Note that it is only the long display labels that make the plot look messy. There is no problem with the internal representation of the Graph. I am about to post an update that deals with this.

@Markiyan Hirnyk You're right. I hadn't noticed that comment in the lengthy thread, probably because it was short and did not display a plot.

@Markiyan Hirnyk You're right. I hadn't noticed that comment in the lengthy thread, probably because it was short and did not display a plot.

You said, "Ok, I've done it". Do you mean that you've done just the uploading (following my Answer), or the uploading and the plotting also (following Markiyan's Answer)?

If you still need to do the plotting, Do you know if the data in the first column (the independent variable) are in numerical order?

You said, "Ok, I've done it". Do you mean that you've done just the uploading (following my Answer), or the uploading and the plotting also (following Markiyan's Answer)?

If you still need to do the plotting, Do you know if the data in the first column (the independent variable) are in numerical order?

@trial123 Your problem is interesting, but I don't know enough mechanical engineering to answer it. Other people may be reluctant to look at your problem because of the extra trouble of viewing the images one-by-one. So you should upload your worksheet. Here's how: In the MaplePrimes text editor, in the second row of the toolbar, the last item is a fat green up arrow. Click on that. You should also upload the diagram.

I find the need to convert to polynomial form strange. Should that be considered a bug? Is there any analogous situation with dsolve?