Carl Love

Carl Love

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10 years, 58 days
Natick, Massachusetts, United States
My name was formerly Carl Devore.

MaplePrimes Activity


These are replies submitted by Carl Love

@zenterix There is a distinction that must be made between declarations and statements, although that distinction has been fading over the years. In a module, the declarations must come before the statements. All of these are declarations:

local defaultSeed;
local defaultSeed:= 100;
export getSeed;
export getSeed:= ()-> defaultSeed;

But this is a statement:

defaultSeed:= 100;

Your error is that you have an export declaration after the above statement.

By combining the declaration of the names and the assignment of their (initial) values, it's possible to write useful modules that are all declarations, no statements. The majority of modules that I write are like that, as is the example that I gave.

For reasons that I don't understand, I seem to be the only one who does it this way. One benefit is that you don't need to retype (and possibly misspell) the variable name.

The reserved words local and export only need to be used once, each followed by a comma-separated sequence of variables with their initial values (exactly like the example I showed). I always do it that way. Sure, you can put local or export in front of every variable, but why would I type any word more than once if I don't need to?

You wrote:

  • One thing you might note is that I am literally trying to learn about Maple from the official documentation. I simply use what is there. Initially I was reading Chapter 8 about Modules of the Programming Guide....

Likewise, my entire knowledge of Maple comes from reading the official documentation (including the Programming Guide), this forum, the fora that existed before this, and experimentation. I haven't learned from any teachers or books about it. I've looked through many third-party books with Maple in the title, and I have many on my shelves. While most of these books do do a decent job of teaching whatever type of math they're trying to teach, their Maple content is appalling. The only exception that I've seen is Calculus the Maple Way by Robert B. Israel, who used to be a frequent contributor here.

@bstuan I'm trying to not give away too much of the solution here, but if I choose the simplest possible examples for g1 and g2, then I get a limit of 0 for one of them, and 1 for the other.

And note that you should be calculating the limit of f(x, g1(x)), etc., rather than f(g1(x)) (which you've typed above).

@ecterrab You wrote:

  • I am forwarding the problem you posted to the people who take care of that, adding it to the database of issues too.

At this point, I don't see any "issue". Perhaps you should wait for clarification from the OP before forwarding. I've already asked for that clarification.

@acer An even better plot can be made by specifying adaptive=true (or, equivalently, simply
adaptive)[*1] and "anchoring" the zeros with sample:

plot(abs(sin(x)/x), x= -2*Pi..10*Pi, sample= Pi*~[$-2..10], adaptive);

[*1] A curiosity: Using a keyword option as an argument without specifying a value is equivalent to setting the keyword to true, regardless of the declared type or default value of the keyword. Example:
P:= proc({opt::anything:= ()}) opt end proc:
P(opt);

                             
true
One may debate the robustness of making use of this feature.

@one man Just 👨 😪 😢 ❤️ 😍 because there's no 👎 menu-based way to enter them pre-programmed into the MaplePrimes interface, that doesn't mean that they can't be entered. You can use character-based methods or a touch-screen 🔑 🗝 🔐 🔟 #️⃣ 3️⃣ keyboard app.🍁 (All the above were automatically generated suggestions by my Samsung keyboard app, which gives menu-based access to 1000s of emojis.)

I changed this from a Post to a Question. Please put questions in the Questions section from now on.

@ianmccr Thanks for responding. Okay, I'll need to update my mental list with yet another new 1D syntax that doesn't work in 2D (it's quite a long list). It can be made to work in 2D by replacing $nops(a) with $1..nops(a).

@moshill Thanks: The additional lecture notes helped a great deal. In that case, the procedures can be shortened to:

#Works in any input mode:
conjcl:= proc(kk::integer, p::prime, n::posint)
local q:= p^n-1, k:= kk mod q, L:= Array([k]), K:= k, t;
    for t do K:= K*p mod q; if K=k then break fi; L(t+1):= K od;
    [seq](L) 
end proc
:

#Only works in 1D input:
conjcl:= (kk::integer, p::prime, n::posint)->
local q:= p^n-1, k:= kk mod q, K:= k;
    [do K until (K:= K*p mod q) = k]
:


These procedures will run much faster for large values of p and n (such as might be used in cryptography) because they avoid direct exponentiation and because they avoid incremental list building.

@ianmccr So, I suppose that you consider what I wrote to be so foul and unworkable that it's not even worthy of comment?

@Anthrazit That's the way it was designed. It's not a bug. If I was redesigning it, I'd exclude the last name evaluation "feature" and handle the prettyprinting of tables, procedures, and modules akin to how rtables and objects are currently prettyprinted. But needing to use eval or entries doesn't seem like a big burden. 

@Jankel I use Maple 2022.2 on Windows 10 with a standard 17-inch HD display. My help Table of Contents font spacing looks exactly like what you showed in your original Question above.

@Ronan I think that it would be best to just write, edit, and store everything in plaintext files. It's fine to test and experiment with the GUI (using 1D input), but put the final work in plaintext files.

Regarding 2D Input: It's so corrupt and deviant at this point that to me it's a separate language, akin to an illiterate's gutter dialect. I don't think that a single syntax innovation made to Maple 1D input within the last 5 years has been incorporated into 2D Input. That includes do-until loops; multilevel break and next in do loops; embedded do loops, if and try statements; embedded assignment operators; updating assignment operators; double-indexed for loops; (the list goes on...). Since it seems that no-one is working on these and it's been so many years, I doubt that it'll ever be done.

I agree: That's a horrible font with a huge number of incorrectly used ligatures. The spacing is "gappy". That slows down reading speed.

There seems to be a lot of bad font-spacing in Maple. 

@nm Maple has the builtin command ilog2, which is extremely fast. Note that I'm using the word builtin in the way that it's usually meant in Maple: something that is coded directly in the kernel rather than being coded in the Maple language and stored in an archive/library. I've seen numerous times where you've used built-in (which you always misspell as "build in")[*1] to refer to any stock Maple command even if it's stored in the library.

type(ilog2, builtin), type(log, builtin);
              truefalse

ilog2 is fundamental to nearly every algorithm in computational number theory.

[*1] Build is, of course, an English verb. Almost any English verb can be used as an adjective, but it must first be put in a participial form. The past participle is used if the adjective is being applied to the verb's object, and the present participle is used if it's being applied to the verb's subject. (Being applied to the object is far more common.) The past participle of build is built.

When two or more words are used together as an adjective (especially as an adjective in its usual position---before the noun that it modifies), the words are usually connected with hyphens. Thus the grammatically correct phrase is built-in command.

@acer For bases other than 2 or 10, you can use indexed ilog. So, no floats are needed, and negative integers are allowed:

1 + ilog[3](22), 1 + ilog[3](-22); 
             3, 3

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