Was experimenting with methods to handle the representation of 3D lines and plotting them. Where I normally use a point and a direction vector to dascribe the line.

With a bit of experimenting I see the element wise operation `+`~  or  `-`~  using prefix notation saves a lot of time converting vector to lists and vice a versa.  Would be interested to know if there are better techniques.

On the plotting side using plot3d Can the colour of the lines be changed individually? Or should I use a different plotting command?

Download Perpendicular_3D_lines.mw

I see a number of MaplePrimes questions answered with good examples using prefix notation.  Is there good reference material somewhere that can show me how to make use of prefix notation when using Maple?  It's not always obvious (to me) how to construct maple commands using prefix operators so I typically just use the standard commands.  Understanding Maples prefix notation would help in understanding some of the answers given to questions in this forum.  Thanks.

Question is attached:

Download variance_of_sum_of_products.mw

Want to make a rectangular graph (in the sense of Graph Theory) of 4 copies of the path A-B-C-D i.e. four rows of this path. Once the rectangular or matrix like graph is made its ediges are to be weighted as the matrix position of vertex stating from (1,1) at the upper left vertex i.e. "A". Help please.

Hi everyone! :)

I'm new to Maple, so please forgive me if the solution is obvious, but I could not find any fitting articles for my problem.

I have a transfer function and need to find the poles. Later, I want to calculate the constants to meet my filter requirements. For now, I'm focusing on getting a symbolic solution and evaluating the poles.

Here's my setup:

Here is the File NoiseFilter.mw

When I use the "evalf" function, it gives me a large sum, but I would like to get one complex numerical result.

I appreciate any help! :)

I would expect I could do

A := DataSeries([2, 3, 4], datatype = float)
B := DataSeries([1, 3, 19], datatype = float)
min~(A, B)

but the last command gives me 

Error, (in DataSeries:-min) invalid boolean expression: 2.

How do I find the element-wise min (i.e. DataSeries([1,3,4], datatype=float)) of two DataSeries?

This code used to work OK in Maple 2023.2.1 on windows 10. Now it gives this new internal Maple error 

Error, (in property/ConvertRelation) numeric exception: division by zero

I think this is new problem in Maple 2024 as I have not seen it before. Will report it to Maplesoft. Mean while if someone has any workaround other than not using the `is` command will try it.

The following are two worksheets. One using 2023 shows it works OK (no error) and one in Maple 2024 with the new error

Download no_numeric_exception_march_7_2024_version_2023.mw
 

Download numeric_exception_march_7_2024_version_2024.mw

I was wondering if this is by design or not. Here is one example., This ode is solved by Maple 2023.2.1 on windows 10. The solution is in terms of DESol though. It takes less than one minute.

In Maple 2024 on same PC, dsolve hangs on it.

If this by design? Since DESol solution is not very useful actually. I was thinking that may be Maple is now trying to return a solution without DESol in it, and that is why it hangs or take long time. I stopped it after 5 minutes. 

Or should I report it to Maplesoft as possible bug?  

Below are 2 worksheets. One using Maple 2023 and one using 2024.

Download dsolve_march_7_2024_maple_2023.mw

Download dsolve_march_7_2024_maple_2024.mw

One may easily spot that the symbols “→” and “⇒” are missing here and here. 

These two PDF files were printed officially, so I think they can be considered examples of best practice for the export functionality. Does this mean that this functionality is still defective in the most recent release?

Download expression_to_simplify.mw

chatGPT version used by the new NaturalLanguage package seems to be using chatGPT 3?. I asked it and this what it said

NL:=NaturalLanguage;
NL:-Query("what is your name?");

"As an Artificial Intelligence, I don't have a personal name. However, If 
you're asking how to represent the question \"What is your name?\" in MathML, 
it's actually irrelevant as MathML is used for marking up mathematical notations, 
not regular text or questions. \n\nBut in English, it's as simple 
as just asking \"What is your name?

Then I asked it 

NL:-Query("what version of chatGPT are you?");

"As an AI developed by OpenAI, I don't have a specific version like software 
programs or applications. I get continuous updates and improvements over time. 
However, as of my current operation, I'm based on GPT-3 model.

some questions: It is possible to make it use chatGPT 3.5 or 4.0 with NL?

How is this free to use and without getting a key from openAI? After agreeing to terms fromn the options menu, can one continue to use it for free? I thought chatGPT requires some fee to use. But I could be wrong.  but this is nice to be able to use it this easily from Maple!

Btw, It is still not very good in math. Asked it to first this simple first order ode and got wrong answer

NL:-Query("what is the solution to the differential equation y'(x)+y(x)=sin(x)");

"Sorry, this query was too complicated. Please rephrase and/or try again."

So I tried

NL:-Query("solve the differential equation y'(x)+y(x)=sin(x)");

"The differential equation given is a first order linear 

   ordinary differential equation. 

  

  The general solution can be obtained through the following 

   steps:

  

  1. Identify the homogeneous part of the equation, which is 

   y'(x) + y(x) = 0. The solution of such a homogeneous 

   equation known as the "complementary function" is y_c = 

   e^(-x) * A. where A is an arbitrary constant which will be 

   determined by a specific condition or boundary value.

  

  2. Find a Particular Integral (solution specific to the 

   nonhomogeneous part of the differential equation) which in 

   this case is y_p = -cos(x)

  

  3. Combine the Complementary function and Particular Integral 

   to get a general solution, y(x) = e^(-x) * A - cos(x).

  

  Now let's express the solution in MathML:"


                            (-x)          
                     y x = e     A - cos x

 "Note: Here A is a to-be-determined constant. If the problem 

    was a boundary value or initial value problem, you would 

    substitute the given values into this general solution and 

    solve it for A."

The solution should be

dsolve(diff(y(x),x)+y(x)=sin(x))

                y(x) = -cos(x)/2 + sin(x)/2 + exp(-x)*c__1

Any idea why parse("a", 'statement') doesn't return the value of the variable, but only its name?

Running the same command directly works.

Download ParseStatement.mw

Hello everyone!

I wanted maple to give me the conditions when my inequality is fulfilled. But maple gives me exactly the same conditions for x (x here as placeholder) >0 and x<0. That makes no sense. The conditions themselves for x>0 (x<0) are also contradictory and illogical. 

Can someone please explain the solutions or what is wrong? I assume that conditions for the inequality to be fulfilled are missing. But I wanted Maple to give me exactly these conditions. I always use the solve command for this.

Thank you very much!

Best wishes
Hahn 

Maple_Forum_Help_Inequalities.mw

I tried inserting contents of my worksheet here but for some reason procedure test2 does not appear. Therefore, here is a screenshot.

What I would like is for the call r() above to print out 3,2 and then 5.

Basically, I'd like to know how I can call a function that has default parameter values with a value that makes the function use the default parameter value.

In the code above, the variable r is assigned to the return value of test2, which is the function called "inner". The function inner accepts an argument "b" and calls the function "test" passing in this "b" as the second argument. If I don't pass any argument to "inner" then it defaults to Null, which then gets passed to "test".

I want this Null to force "test" to use its default value for parameter "b".

PS As an extra, why does it give a "not able to parse" error when we declare a local inside of a proc as above? Note that I have it commented out. 

Download Curry.mw