Better doc for beginners?

[liufuyang]

Hi there,

As a beginner for our nice looking tool, it seems that I cannot find a good beginner level, step by step tutorial for rust ndarry in our repo?

To draw some users from python numpy to start using rust numpy, I feel that it could be very helpful to have some readme doc or a site presenting some information like this?
https://numpy.org/devdocs/user/quickstart.html

A quickstart doc would be very helpful, isn't it? Not sure how busy you are, but maybe I can try start making some simple doc, basically port some or all the example operations from https://numpy.org/devdocs/user/quickstart.html to some read me here would be helpful.

Also, I wonder, how a site/book like this is generated https://doc.rust-lang.org/rust-by-example/hello.html
I guess it would be nice that eventually we have a doc site for rust-ndarry (or perhaps there is already some?)

Thank you :)

[LukeMathWalker]

A quickstart doc would be very helpful, isn't it? Not sure how busy you are, but maybe I can try start making some simple doc, basically port some or all the example operations from https://numpy.org/devdocs/user/quickstart.html to some read me here would be helpful.

That would be extremely valuable!

Also, I wonder, how a site/book like this is generated https://doc.rust-lang.org/rust-by-example/hello.html

They are using mdBook

[jondo2010]

Hi, don't forget that there is already a very nicely done section on ndarray for users that already have experience with numpy: https://docs.rs/ndarray/0.13.0/ndarray/doc/ndarray_for_numpy_users/index.html

[liufuyang]

Thank you both. Good to know. I guess the above link is a bit hidden in the root readme(though it is very valuable). And it seem not very beginner friendly. Let me see whether I can find some time to work on making a simple doc first see how it looks. I am not using numpy everyday and also very new to our rust-ndarry. So even for me it feels a bit difficult to just start writing the doc as what I need is a doc that I am about to write 😄

[yutiansut]

Hi, don't forget that there is already a very nicely done section on ndarray for users that already have experience with numpy: https://docs.rs/ndarray/0.13.0/ndarray/doc/ndarray_for_numpy_users/index.html

wow this is definitely great!

[liufuyang]

@LukeMathWalker Hey Luke, I tried to make a small but hopefully beginner tutorial readme file. Perhaps you think it is is nice to have?

All the example code there is runnable in https://play.integer32.com/ playground :)

[LukeMathWalker]

Hey!
I'll have a look tomorrow 😁 @liufuyang

[psotos]

I am switching from C++ to Rust and I need this tutorial badly! I am really stuck. I am getting errors like this:

error[E0271]: type mismatch resolving `<(u16, u16) as ndarray::shape_builder::ShapeBuilder>::Dim == ndarray::dimension::dim::Dim<[usize; 2]>`
  --> src/advanced_noise.rs:44:20
   |
44 |     let mut grid = Array2::zeros((width, height));
   |                    ^^^^^^^^^^^^^ expected struct `ndarray::dimension::dim::Dim`, found tuple

Does this mean that I need to use:
let mut grid = Array2::zeros(width*height,2); ??

Also how to return a grid from a function is confusing as well. A tutorial would be very helpful!

[andy-thomason]

Likely you will need to use a type specification such as Array2::<f32> and cast width and height to usize. I could help Luca write something if you like. I had to learn all this myself in the last few months.

…

On Wed, Apr 8, 2020 at 1:49 PM Peter Sotos ***@***.***> wrote: I am switching from C++ to Rust and I need this tutorial badly! I am really stuck. I am getting errors like this: error[E0271]: type mismatch resolving `<(u16, u16) as ndarray::shape_builder::ShapeBuilder>::Dim == ndarray::dimension::dim::Dim<[usize; 2]>` --> src/advanced_noise.rs:44:20 | 44 | let mut grid = Array2::zeros((width, height)); | ^^^^^^^^^^^^^ expected struct `ndarray::dimension::dim::Dim`, found tuple Does this mean that I need to use: let mut grid = Array2::zeros(width*height,2); ?? Also how to return a grid from a function is confusing as well. A tutorial would be very helpful! — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub <#778 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AAL36XHMD5LWSVNGUDZ7N5LRLRXHNANCNFSM4KJUXZWQ> .

[psotos]

@andy-thomason Please do that write up! I am so new to Rust and struggling with Arrays. In other languages Arrays are easy. In Rust, so confusing. Its mostly what is the correct syntax? I still have no idea.

[andy-thomason]

The "Turbofish" and the borrow checker were the most confusing thing for me, coming from a C++ background.

…

On Wed, Apr 8, 2020 at 5:13 PM Peter Sotos ***@***.***> wrote: @andy-thomason <https://github.com/andy-thomason> Please do that write up! I am so new to Rust and struggling with Arrays. In other languages Arrays are easy. In Rust, so confusing. Its mostly what is the correct syntax? I still have no idea. — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub <#778 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AAL36XDP3XGSVU44DTKAXNTRLSPBNANCNFSM4KJUXZWQ> .

[psotos]

I don't even know what those two things are. Sounds like I need to watch the full Udemy tutorial that I bought. LOL

Turbofish sounds like something that can be bought at a NAPA store.

[andy-thomason]

Indeed! Enjoy!

…

On Wed, Apr 8, 2020 at 7:11 PM Peter Sotos ***@***.***> wrote: I don't even know what those two things are. Sounds like I need to watch the full Udemy tutorial that I bought. LOL Turbofish sounds like something that can be bought at a NAPA store. — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub <#778 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AAL36XBKRSEMS6X3ECHE5SDRLS46NANCNFSM4KJUXZWQ> .

[psotos]

I still cannot get this syntax right. Nothing works. I feel like 10,000 monkeys on 10,000 pianos at this point. Let me just ask anyone. How do I create a multi-dimensional (two dimensions only of row, col) array of type boolean, that has an unknown size at compile time? It's killing me. Why is this so hard?

I want to create this array in a function and then return it back to the caller. This function is sort of a factory class.

Any help is much appreciated!

[psotos]

Here is the code that I am trying to get to compile with no success:
`pub fn threshold_noise(height :u16, width: u16, threshold: f32) -> Array2 {
let perlin = Perlin::new();

// let mut grid = [width][height];
let mut grid= Array2::zeros((4, 2));
for x in 0..width {
    for y in 0..height {
        let ary = [x as f64,y as f64];
        let noise_val = perlin.get(([1.0f64, 1.0f64]));
        println!("noise value: {}", noise_val);
        if noise_val <= ((threshold * 2.0f32) -1.0f32) as f64 {
            grid[[x as f64,y as f64]] = true;
        }
    }
}
return grid;

}`

Here is the error that I get:

    grid[[x as f64,y as f64]] = true;
   |                 ^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `ndarray::dimension::ndindex::NdIndex<ndarray::dimension::dim::Dim<[usize; 2]>>` is not implemented for `[f64; 2]`

Any help is greatly appreciated! I am at my wits end here and ready to abort on this library.