dharr

Dr. David Harrington

6307 Reputation

19 years, 348 days
University of Victoria
Professor or university staff

Social Networks and Content at Maplesoft.com

I am a professor of chemistry at the University of Victoria, BC, Canada, where my research areas are electrochemistry and surface science. I have been a user of Maple since about 1990.

values...

@JAMET   {a = 1.354182738 c, b = 1.149311492 c, c = c} means c can be anything, e.g., if c=1, then a = 1.354182738 and b = 1.149311492. If you choose other c values you will get other a and b values.

geometry...

@JAMET I assume you are talking about the prompts from the geometry package. From the help page ?geometry:

"A simple way to set the names without being prompted is to set the environment variables _EnvHorizontalName and _EnvVerticalName to the axes names that you prefer; otherwise, Maple will prompt you to input of the name of the axes."

version difference...

@MaPal93 Perhaps a version difference. Pity, since yours has italic "=0".

 > InertForm:-Display(`%>`(%limit(X[i] %^ (rho = 0), alpha = infinity), 0), inert = false)

 > plot(x^2,title=InertForm:-Display(`%>`(%limit(X[i]^`ρ=0`, alpha = infinity), 0), inert = false));

 >

eval...

if sol[2]  gives  {x=3, y=5}, then

eval(x, sol[2])  gives 3
eval(y, sol[2]) gives 5

eval(x^2+y, sol[2]) gives 14

eval([x,y], sol[2]) gives [3,5]

Note. sol[2,1] is not recommeneded because the sets do not have a specified order. Solve can give lists instead of sets using

solve([fx, fy], [x, y])

rhs(x=3) gives 3, lhs(x=3) gives x.

@vs140580 Open Maple is for working at the individual command level, e.g., calling a procedure, but if you want to use an existing worksheet file, it would be simplest to have a worksheet that reads a file that python produces, and then writes a file that python uses.

Then probably you could from within python do:

1. write a file for maple to use

2. initiate Maple by some system call from python (most languages have this, but I'm not a python user so I don't know)

3. wait until the file maple writes exists

Alternatively you could run Python and Maple by turns in a batch file from your operating system.

directly from Jupyter or Open Maple....

See help for Jupyter for using Maple directly from Jupyter notebooks (without using Python) in Maple 2022 and later. To call Maple directly from within Python, Open Maple may be used, see ?OpenMaple,Python,API

Note also that there is the possibilty to use Python from within Maple - see help on the Python package. Python code can also be directly entered into a code edit region.

data source?...

I can use Tools -> Assistants -> Import data to successfuly read an Excel file on my local machine, which I think you can also do (but maybe "copy into Excel" means something else). If so, what sort of file locations can you not successfully read, and what is the result (hangs?, error message?...).

You have a large polynomial system that is going to be slow. Among other changes, removing the explicit option saves about 25%. I have also added general suggestions that may be useful in the future.

new1.mw

solve, identity...

@salim-barzani Solve(identity(... takes an equation, not multiple equations as CoefficientNullity is.

So you could use

`solve(identity(J, xi), {k, w, A[0], A[1], B[1], a[1], a[2], a[3], a[4], a[5]})`

or (probably faster)

`solve(identity(DEq1_1, Z), {k, w, A[0], A[1], B[1], a[1], a[2], a[3], a[4], a[5]})`

@salim-barzani So do it in small parts. A2 looks right here but how can A1 have f(something) + f(something) if it is f(sum)? Maybe that is what the seq was for (should have been add), but if that is the case then A2 can't be right.

Very confusing.

Mp.mw

seq...

Your seq(expr, m=1..2) just makes two copies of expr, so you have f(expr, expr). Maple ignores the second argument so you just get f(expr). Aside from that it does what you ask it. eval(something, lambda=0) is preferred over subs(lambda=0, something) as it it mathematically smarter, though in this case it doesn't make any difference.

combining properties...

@salim-barzani you can use And and Or to combine properties, e.g.
assuming Or(positive, negative); [all variables real and nonzero]
assuming Or(x::positive, x::negative) [x real and nonzero]

assuming x<>0 [x non-zero but could be complex]

See the help pages ?assuming  and ?assuming,details

no real reason...

@Nicole Sharp I kept 2015 as it is an institutional licence that my students had access to. But 2022 and 2023 were just licenced to me, and I kept 2022 when I updated to 2023 "just in case". Now I have updated to 2024 on a different computer and will soon junk the old computer and all three earlier versions. Decreases in capability are very rare. I don't know anything about Quandl, but it seems the DataSets package has just changed so similar data is now built-in to Maple, so there is perhaps not much decrease in capability?

multiple versions...

In general, there is no problem having multiple versions - I have a windows 10 system with 2015, 2022 and 2023 happily coexisting.

arclength...

@one man With apologies to Rouben, I hacked his code to get the arclength, which for his solution agrees approximately with your second solution. Is your first one just symmetrically equivalent with not very accurate arclength? It might be possible to get such solutions from Rouben's code by givng dsolve an approximate initial solution.

geodesic-on-rounded-cube-arclength.mw

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