adding support for linear algebra operators

[lileicc]

1. vector plus, minus (result is a vector, i.e. Real[])
2. vector scalar multiplication (result is a vector, i.e. Real[])
3. scalar vector multiplication (result is a vector, i.e. Real[])
4. matrix plus, minus, multiplication (result is a matrix, i.e.
   Real[][])
5. matrix scalar multiplication (result is a matrix, i.e. Real[][])
6. scalar matrix multiplication (result is a matrix, i.e. Real[][])
7. matrix vector multiplication (result is a matrix, i.e. Real[][])
8. vector matrix multiplication (result is a vector, i.e. Real[])
9. matrix inverse (result is Real[][])
10. matrix determinant (result is Real)
11. subscript expression. Result is row vector for Real[][], and Real scalar for Real[]. The index can be random Integer as well.

[cberzan]

I think you meant [][] on the line above

[cberzan]

@lileicc Looks good, and I verified that the example works. Go ahead and merge 👍

[cberzan]

@lileicc By the way, to avoid merge pain in the future, if we have to change the whitespace / indentation of a file, let's do this:

1. pull request that changes the whitespace / indentation AND NOTHING ELSE
2. merge the above into master
3. another pull request that does the actual changes to the code

That will make reviewing / merging into existing branches much easier.

[lileicc]

Does ?w=1 work?

On Wed, Feb 12, 2014 at 3:32 PM, cberzan notifications@github.com wrote:

@lileicc https://github.com/lileicc By the way, to avoid merge pain in
the future, if we have to change the whitespace / indentation of a file,
let's do this:

1. pull request that changes the whitespace / indentation AND NOTHING ELSE
2. another pull request that does the actual changes to the code

That will make reviewing / merging into existing branches much easier.

Reply to this email directly or view it on GitHubhttps://github.com//pull/54#issuecomment-34931703
.

[cberzan]

Does ?w=1 work?

It works, but when in this mode, you can't make comments on the diff.

Anyway, doesn't matter for this PR, just for the future.

[cberzan]

@lileicc For the automobile model I need to add scalars and vectors. Minimalist example:

fixed Real laser_theta = 1.23;
fixed Real[] laser_angles = [1.0; 2.0; 3.0];
fixed Real[] sum = laser_theta + laser_angles;

query sum;

Currently this doesn't work. Should we also add functions "scalar op vec", "scalar op mat", "vec op scalar", and "mat op scalar"?

[cberzan]

@lileicc Also, how do I take an indicator function in BLOG? For example, I need a function y = f(x) s.t. y[i] = 1 if x[i] >= 0, and 0 otherwise.

[WilliamCushing]

random Real y(Real x) ~ if (x>=0) 1 else 0;

"fixed" and "=" might also work, and would surely be dramatically more
efficient if it does. I might have made a small syntax error, but I know
for sure that something like the above does work; I used the trick to get
BLOG to do purely logical inference in another model.

-Will

On Thu, Feb 13, 2014 at 4:04 PM, cberzan notifications@github.com wrote:

@lileicc https://github.com/lileicc Also, how do I take an indicator
function in BLOG? For example, I need a function y = f(x) s.t. y[i] = 1 if
x[i] >= 0, and 0 otherwise.

Reply to this email directly or view it on GitHubhttps://github.com//pull/54#issuecomment-35042061
.