Strangeness.maple

the procedure q discussed above does not have a ; after sin(x) in my worksheet.It only appears after I cpy and paste.
 

q:=proc(x)

sin(x)

  end proc;
 

is what I see.

@vv I guess you are right. The procedure you provided is neat!
 

I still think the help pages should warn folks about the procedure, or, even better, incorporate your procedure.

@Kitonum Hi,

Inserting the evalf in abs(x) is certainly better but my problem is in some mysterious hidden quotes in the worksheet. That is why the error message says "unable to delimit..."  The copied version of the worksheet I first entered (as opposed to the uploaded version above) shows those quotes.

 

@Carl Love 
 

Download proc.description_.mw

@Carl Love 

The interlaced quotes do not appear on my worksheet-only appear when I copy and paste. Also, the procedures are duplicates-copied and pasted; only the # is different.

@Preben Alsholm 

There are many people (perhaps most) who do not read the instructions but rely on some form of uniformity to operate their TV's ,computers, dishwashers etc. Others read the manuals. Similarly, some of us read the documentation and others (myself included) just look for an illustartive example that covers the case we are interested in.  A matter of style I think.

@Preben Alsholm inconsistency means that (unless the documentation is very complete) one must experiment with each command before you can use it with confidence.

Thank you for your reply. Yes, one can convert to standard syntax easily enough (you do it better than I did so I will use your code) but why does dsolve object ONLY when the numeric option is called. It DOES work symbolically.

@Carl Love 

Yes, parentheses are a programmers best friend!

@vv Thanks,  I did not think of that.

@Axel Vogt 

Sorry, I don't understand your comment.

@Carl Love 

I understand now. It is like trying to plot
f := proc (x) options operator, arrow; if Pi < x then x^2 else -x end if end proc;

plot(f)

Works fine but

plot(f(x), x = -5 .. 5);
Error, (in f) cannot determine if this expression is true or false: Pi < x

plot('f(x)', x = -5 .. 5) also works for the same reason I guess.

I appreciate the clear explanations and the stylistic improvements also. Many thanks.

@Carl Love 

I understand that you have reformatted the input to meet Maple requirements for the plot3d command.
That is the difference between td and TD.

Also, the option remember addition to spped things up by a factor of 3 is clear. 

However, the eval command is the magic which somehow prevents premature evaluation in this case.

I do not undertand what is going on.

The alternative solution you proposed using an if statement works equally well but I also find that a bit mysterious as well as your comment about "bound variables". Could you please explain that?

@_Maxim_ I agree completely.

BTW,in my case doing the computaion 3 times does consume significant time.