Re: [racket-users] Matrix Indexing Operations in "math/matrix"

2018-10-07 Thread Sam Tobin-Hochstadt
The `math/matrix` library aims at functional arrays, that is arrays that aren't mutated but are instead transformed into new arrays. However, if you want mutable arrays, then you should probably use the `mutable-array` constructor to create them, and then `array-set!` will work. Sam On Sun, Oct 7

Re: [racket-users] Matrix Indexing Operations in "math/matrix"

2018-10-07 Thread Ricardo Iglesias
> > >I think you want the `matrix-ref` function. > While this does give me the value, I am unable to set it. Calling (define M (matrix ([1 2 3] [4 5 6]))) (set! (matrix-ref M 0 2) 5) Leads to the error: ; .../Example.rkt:228:6: set!: not an identifier - And array-set! for cha

Re: [racket-users] Matrix Indexing Operations in "math/matrix"

2018-10-07 Thread Jens Axel Søgaard
And array-set! for changing the value of an entry. /Jens Axel Den søn. 7. okt. 2018 kl. 16.46 skrev Sam Tobin-Hochstadt < sa...@cs.indiana.edu>: > I think you want the `matrix-ref` function. > > Sam > On Sun, Oct 7, 2018 at 12:30 AM Ricardo Iglesias > wrote: > > > > Sorry for the confusing wor

Re: [racket-users] Matrix Indexing Operations in "math/matrix"

2018-10-07 Thread Sam Tobin-Hochstadt
I think you want the `matrix-ref` function. Sam On Sun, Oct 7, 2018 at 12:30 AM Ricardo Iglesias wrote: > > Sorry for the confusing wording. > Basically, All I want is to be able to do > G[ row ][ col ] = value > > In Racket. I've been messing with Racket this afternoon and have an engine > that

Re: [racket-users] Matrix Indexing Operations in "math/matrix"

2018-10-06 Thread Ricardo Iglesias
Sorry for the confusing wording. Basically, All I want is to be able to do G[ row ][ col ] = value In Racket. I've been messing with Racket this afternoon and have an engine that is able to index into matrices, and just implemented several common matrix operations, such as transpose, matrix mu

Re: [racket-users] Matrix Indexing Operations in "math/matrix"

2018-10-06 Thread Christopher Lemmer Webber
Ricardo Iglesias writes: > Good afternoon. I'm trying to move away from things like Matlab and SciPy > to do linear algebra work. > Something I notice I do a lot is indexing operations, such as > MATRIX[ row ] [ column ] > > I'm looking at the "math/matrix" library provided here: > https://doc

[racket-users] Matrix Indexing Operations in "math/matrix"

2018-10-06 Thread Ricardo Iglesias
Good afternoon. I'm trying to move away from things like Matlab and SciPy to do linear algebra work. Something I notice I do a lot is indexing operations, such as MATRIX[ row ] [ column ] I'm looking at the "math/matrix" library provided here: https://docs.racket-lang.org/math/matrices.html, a