Swift Matrix Library

This is a very cool project. I'm wondering if there is any interest in adding a shape attribute of ndarrays? I see there is some interest (for good reason) in being similar to numpy/matlab, and the program I'm writing makes its own shape variables for ndarrays. I'd make a pull request if project maintainers believe it would be a desirable and straightforward change.

The function name is read_csv2. It takes two arguments: filename and whether it contains header (i.e. first row does not contain data, but variable names). I made several changes:

1. As mentioned above, many times the csv files use first row as variable names, so by setting header=true we will ignore first row. The "header" just follows R's routine.
2. Many times the csv files are created under Windows platform, so the line break is actually "\r\n" instead of "\n". I check if there is "\r" and delete all of them.
3. The data in the csv file may not only be numeric. It might be categorical, e.g. "M" and "F", "Y" and "N". The original read_csv will ignore these categorical variables. I use different approach: I create a dictionary [String:Int], the key is the categorical value (e.g. "M") while the value is Int (e.g. 0). All the keys are stored in a set. A set means identical values will be considered as one element. Once we encounter a categorical value, first we check if it is in the set. If yes, we look up the dictionary and add its value to the data; Otherwise we create a key-value pair and insert the key into the set. So if the column is M,F,F,M, it will be 0,1,1,0 in the final data.

Please give a detailed and working steps for installing swix on a new project. I tried several times to follow the given steps. First I found that OpenCV must be added as Framework in order to compile the project. In this way the project compiles but the functions cannot be called in any swift file, how to make swix to work?

Many thanks

Hi Scott, I have done a lot of rework, and it's not complete yet. However, I like you to have a look at it. There are now two frameworks for pure OO and one with additional wrappers for functional access (not complete). There's also the test suite (adapted). Biggest changes:

• two different frameworks (OO and F)
• vector and matrix as classes are now capitalized.
• init stuff is not in a functional manner but using class inits with different signatures
• functional access is decoupled (and will then be available through the F-framework)
• quite some minor changes
• using internally just the OO-methods

So, why? Swift it not a functional language and should not be programmed that way. You are a mathematician like my wife and I know that you have quite a functional thinking (as can well be seen from your programming style). E.g instead of

arange(n)

it's now

Vector(arange:n)

Looks like more typing, but for outer access there will be the F-wrapper which allows still for the first form. So for people who are somehow used to that, there will be no difference.

There are still some issues with scoping I need to fix (as already said: Matrix allows to modify the flat vector without any check which is no good). Since the compiler allows to forbid those invalid accesses it shall be implemented. Quite some more bits and pieces I currently can't recall.

Running this little Python snippet on my machine takes 3.5 seconds:

import numpy as np
import time

t = time.time()
for i in range(1000):
    a = np.arange(100000)
    a += 1
    a = a * a
    a = a / a
    b = np.ones(100000)
    if not np.allclose(a, b): print "?"
print time.time() - t

The corresponding Swix-variant takes 33.7 seconds (factor 10 slower than NumPy).

Everything works fine on the Simulation, as soon as I plug any device I cannot install the App. The following error appars.

ld: '/mypath/myproject/swix/objc/opencv2.framework/opencv2(knearest.o)' does not contain bitcode. You must rebuild it with bitcode enabled (Xcode setting ENABLE_BITCODE), obtain an updated library from the vendor, or disable bitcode for this target. for architecture armv7
clang: error: linker command failed with exit code 1 (use -v to see invocation)

It seems a clang problem any idea how to solve it?

Opinions on including some plotting functionality? It would probably not be a random window popping up like in MATLAB, but maybe it could output to a PNG, or a UIView / NSView, which could then be embedded directly in the given app's view hierarchy?

Here it is.

These tests should be good enough. I think.

Edit

Ah, I see. You're working now on the package-manager branch. Take your time... :) Maybe I'll drop a PR to help you implementing/porting/testing stuff ^^

With Swift still changing, factor methods are being replaced by constructors. Not sure what timeline is best for this, but at some point code such as:

var x = String.stringWithContentsOfFile(prefix+"../"+filename, encoding: NSUTF8StringEncoding, error: nil)

needs to be changed to:

var x = String(contentsOfFile: prefix+"../"+filename, encoding: NSUTF8StringEncoding, error: nil)

to continue building (thats necessary as of Xcode 6.1 beta 2)

First removed .DS_Store from Git tracking. Then added .DS_Store to .gitignore.

The file has nothing to do with the code that is being tracked in git. It contains custom attributes set on the containing folder in the Finder. Unless those custom attributes are relevant to the code, that file is just noise. Additionally, if the file is not ignored and gets checked in unintentionally and later two devs each decide to put say, pretty custom icons on the folder (for whatever reason), then you could end up with a merge conflict on a binary file.

linear and quadratic (polynomial) regression added. To illustrate regression, I implemented a RegressionView - subclass of UIView - allowing us to draw hypothetic data (x, y). Also the degree of the hypothesis can be adjusted with a UIStepper above.

In the swift speed benchmark, introduced in commit e0cd9df

https://github.com/stsievert/swix/blob/522cb65f076a96ca89a591bc96510d98f7d24006/swix/speed/speed.swift#L16

https://github.com/stsievert/swix/blob/522cb65f076a96ca89a591bc96510d98f7d24006/swix/speed/speed.swift#L19

https://github.com/stsievert/swix/blob/522cb65f076a96ca89a591bc96510d98f7d24006/swix/speed/speed.swift#L22

https://github.com/stsievert/swix/blob/522cb65f076a96ca89a591bc96510d98f7d24006/swix/speed/speed.swift#L41

https://github.com/stsievert/swix/blob/522cb65f076a96ca89a591bc96510d98f7d24006/swix/speed/speed.swift#L46

https://github.com/stsievert/swix/blob/522cb65f076a96ca89a591bc96510d98f7d24006/swix/speed/speed.swift#L52

Hi!

I am trying to install swix in this project https://github.com/hollance/Forge/tree/master/Examples/YOLO. After following the swix manual install instructions of adding the swix folder to the project and adding swix-master/swix/swix/swix to the objective c bridging header and running, I get this error Ambiguous use of operator '/', pointing to these line of code as canidates. func / (lhs: Int, rhs: Int) -> Double{ return lhs.double / rhs.double} func / (lhs: Double, rhs: Int) -> Double{ return lhs / rhs.double}

I also get an error Use of unresolved identifier 'Process', pointing to this line of code

Process.launchedProcess(launchPath: "cd", arguments: [S2_PREFIX+";", PYTHON_PATH, "imshow.py", filename, "(save)", "(show)"]) print("savefig: Removing CSV FILE " + S2_PREFIX + "temp.csv") Process.launchedProcess(launchPath: "rm", arguments: [S2_PREFIX+"temp.csv"])

This is on xcode version 8.3.3. What is the cause of these issues? Any advice on fixing?

Thank you so much! Jordan

the fft and ifft implementations in complex-math.swift are wrong:

• the number of elements inside the input (real) array must be a power of 2 for the FFT to give correct results
• as stated at https://developer.apple.com/library/ios/documentation/Performance/Conceptual/vDSP_Programming_Guide/UsingFourierTransforms/UsingFourierTransforms.html the output of Accelerate fft functions must be re-scaled: you're already dividing by 2 the output of forward real transforms, while you should divide by n (not 2048) the output of inverse real transforms.