Built-in help for abscissa, apply and map
11-13-2016, 11:47 AM
Post: #1
 JMB Member Posts: 98 Joined: Jan 2016
Built-in help for abscissa, apply and map
I'd like to point out to some errors in the calculator's built-in help, for the functions abscissa, apply and map (FW 10638).

abscissa
The text of the second example is: abscissa(point(1,2,3))
It should be: abscissa(point(1,2,3)) → 1

apply
The text of the first example is: apply(x->x^3,[1,2,3]) → [1,8,27]
It should be: apply(xx^3,[1,2,3]) → [1,8,27]

The text of the second example is: apply(x->x+1,[[1,2,3],[1,2,3]],matrix)
It should be: apply(xx+1,[[1,2,3],[1,2,3]],matrix) → [[2,3,4],[2,3,4]]

By the way, it looks a little odd to me that the word "matrix" has to be added in order to get good results, but that's the way it is, because: apply(x→x+1,[[1,2,3],[1,2,3]]) ENTER, returns the wrong answer: [[1,2,4],[1,2,4]]. I've also noticed that the word "matrix" must be written in English, regardless of the calculator's language setting.

map
This functions works in the same way as apply regarding to matrices, i.e. the word "matrix" has to be added in order to get correct results. I think that this should be stated in the calculator's help.
map([[1,2,3],[1,2,3]],x→x+1,matrix) ENTER, returns the correct answer: [[2,3,4],[2,3,4]]
map([[1,2,3],[1,2,3]],x→x+1) ENTER, returns the wrong answer: [[1,2,4],[1,2,4]]
11-13-2016, 01:34 PM (This post was last modified: 11-13-2016 01:53 PM by compsystems.)
Post: #2
 compsystems Senior Member Posts: 1,384 Joined: Dec 2013
RE: Built-in help for abscissa, apply and map
In CAS mode, there is no MATRIX data type, so that the compiler can interpret it is required to help with the word "matrix"

The container or limiter [] means many things, list, vector, matrix

Discussions on lists, arrays, vectors, arrays