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PS2 Q4

https://course.dyalog.com/user-defined-functions/#marking-tests

Way back in problem set 4 you wrote a dfn to convert test scores into letter values.

https://course.dyalog.com/array-logic-data-driven-conditionals/#the-shape-of-data

currently shown in a brief example, and then used repeatedly hereafter

forumla -> formula

https://course.dyalog.com/Reading/

https://course.dyalog.com/basic-syntax-and-arithmetic/#the-index-generator has

|  |  |
|--|--|
|**Traditional Mathematical Notation (TMN)** | **APL** |
| $\sum_{n=1}^N n$ | `+/⍳N`

instead of

| Traditional Mathematical Notation (TMN) | APL |
|--|--|
| $\sum_{n=1}^N n$ | `+/⍳N`

per @suemanning

this project should be versioned using Mike

"first" and "last" in left-to-right reading order is assumed, but that is not universal, be explicit that "first" means both left-most and outer-most and "last" means right-most and inner-most.

https://course.dyalog.com/Ufns/#name-scope-locals-and-globals

var∘←'lexical'⍵ is an exploit of an implementation edge condition, and not theoretically correct behaviour of dfns. Although people may use this, it should not be encouraged and certainly not demonstrated in an introductory text like this

How do I load a single text file with multiple function/operator definitions and run it?
Is the dfn bug worth mentioning? Can it be referenced from e.g. Orchard?
What about ⎕FIX and tacit functions?

Also consider being opinionated and encouraging use of Link.

Q2 why does the following return 70? -> why does the following return 70 in APL?

https://course.dyalog.com/Data/#convenient-text-input
" There is also a utility function The utility function"

Or just link to the course or put development info there

under problem 4. a. the solution was b×÷a, but that is b÷a because multiplication by reciprocal is the same as division.

AddRows ← {⍵+(⍴⍵)⍴⍺} should say AddRows ← {⍺+(⍴⍺)⍴⍵}

Feedback from user:
Q7 answer mentions selfie (not the single arg case)--is this the first time it appears, or have I missed the explanation?

https://course.dyalog.com/array-logic-data-driven-conditionals/#problem-set-3

https://course.dyalog.com/dfns-and-assignment/

From here, when functions are first introduced, F⍵ ("eff omega") denotes a monadic function f and ⍺F⍵ ("alpha eff omega") denotes a dyadic function.

Should be capital F

https://course.dyalog.com/array-logic-data-driven-conditionals/#problem-set-3

From a user
「Just a small comment on the Basic Syntax page (course.dyalog.com/basic-syntax-and-arithmetic).

In the section on Order of Execution, the third example shows an incorrect result. I was confused until I clicked the Show me step-by-step. The example shows

(10×⍳2)+5

and gives an incorrect result

16 17

But the Show me step-by-step shows that the multiply symbol is supposed to be an add symbol and in that case, the result is correct.」

Downloading data from the internet should link to https://dyalog.github.io/HttpCommand

Feedback from a user

Q5 AddTable ← {i∘.+i←¯1+⍳1+⍵}: Very picky but use a variable name other than i (maybe longer?), this is hard to parse, took me a while

This was my stumbling point in trying to find a good solution, unless we just prepend it uniformly, but your solutions do not return it at all.

The glyph boxes on https://course.dyalog.com/basic-syntax-and-arithmetic/#functions-and-arguments

and the abbreviation (TMN) on https://course.dyalog.com/basic-syntax-and-arithmetic/#the-index-generator

show text on hover, but it is not obvious that you are not supposed to click them

plugins:

• search
• awesome-pages
• section-index

currently awesome-pages and section-index aren't used, and are causing automated build process to fail

https://www.youtube.com/watch?v=eBEwBSO5mBA

In the info box of https://course.dyalog.com/array-logic-data-driven-conditionals/#logic-and-conditions, link to:

https://nbviewer.org/github/Dyalog/dyalog-jupyter-notebooks/blob/master/Boolean%20Scans%20and%20Reductions.ipynb#Sixteen-logical-functions

Booeleans -> Booleans

12 Dec 2022
wrong answer in example question in "Array Logic and Data-driven Conditionals" for grille Grille grid.

It currently says
grille Grille grid
THISISFUN

The example output should be
ILIKEAPL

The text could be made more accessible by trying to simplify the English. The new jargon and concepts are hard enough.

Use a tool like https://readabilityformulas.com/freetests/six-readability-formulas.php to test reading age and attempt to lower it

Wouldn't it be nice if multiline code blocks let you copy the input code line only

In https://course.dyalog.com/loops-and-recursion/
The top info box has broken links to sections on each and on scalars