cwise docs out of data?

[matt-erhart]

In some of the examples, a cwise function can be called these two ways:

let somearray = cwiseFunc(arr1, arr2)
cwiseFunc(somearray, arr1, arr2)

I could only get the second to work, so I wonder if the docs aren't up to date in this and perhaps other ways. Also, is this expected to work without the browserify transform or is that just to get size down? I'm in webpack.

In the mean time, any links to repos making use of cwise would get great to check out.

[rreusser]

@matt-erhart I think it depends on the specific operation what the inputs and outputs are. In particular from the docs:

If no return statement is specified, the first ndarray argument is returned

That means there's not necessarily a single answer to what the return value would be. A reduction operator (like a sum or a max, etc.) would return the sum while other operators by default would return the first ndarray argument.

If you use ndarray-ops, the functions are pretty explicit about whether it's an in-place operator or not, e.g. add (c = a + b) vs. addeq (a += b). ndarray-ops also uses precompiled operators so that you don't have to worry about the browserify transform. In other words, ndarray-ops doesn't cover every use-case but the code is already transformed, which might be helpful.

As for the browserify transform, that's correct. You can use cwise with or without it. cwise uses esprima to parse the function code. This makes writing the body of the operator very easy but allows cwise to be sophisticated about how it actually applies the transform (in particular, it performs math in an inner loop instead of actually calling body as a function). Esprima is a pretty big dependency though. Without the browserify transform, esprima is a dependency and the operator is created in user-facing code. With the transform, the operator is created at build time so that esprima is not a client-side dependency. I think you can use ify-loader to use the cwise transform with webpack. I don't have an example repo on hand, but if you have success with this method, I'd love to hear about it!

[rreusser]

(Apologies for the scattered answer. You're basically correct. Things should work just fine, but if you run into problems, don't hesitate to ask more questions.)