move nim to top level, add to README

README.md

@@ -13,29 +13,35 @@ The title of this repository is a pun on two meanings of "time to": "how much ti
 - [x] Squiggle 
 - [x] Javascript (NodeJS)
 - [x] C
+- [x] Nim 
 
 ## Performance table
 
 With the [time](https://man7.org/linux/man-pages/man1/time.1.html) tool, using 1M samples:
 
-| Language | Time      |
-|----------|-----------|
-| C        | 0m0,442s  |
-| Node     | 0m0,732s  |
-| Squiggle | 0m1,536s  |
-| R        | 0m7,000s  |
-| Python (CPython)  | 0m16,641s |
+| Language             | Time      |
+|----------------------|-----------|
+| Nim                  | 0m0.183s  |
+| C                    | 0m0,442s  |
+| Node                 | 0m0,732s  |
+| Squiggle             | 0m1,536s  |
+| R                    | 0m7,000s  |
+| Python (CPython)     | 0m16,641s |
 
+I was very surprised that Node/Squiggle code was almost as fast as the raw C code. For the Python code, it's possible that the lack of speed is more a function of me not being as familiar with Python. It's also very possible that the code would run faster with [PyPy](https://doc.pypy.org).
+
+I was also really happy with trying [Nim](https://nim-lang.org/). The version which beats all others is just the normal usage of Nim, in the "release" compilation mode (the "danger" compilation mode shaves of a few more miliseconds). The Nim version has the particularity that I define the normal function from scratch, using the [Box–Muller transform](https://en.wikipedia.org/wiki/Box%E2%80%93Muller_transform#Basic_form). For Nim I also have a version of the code which takes around 4 seconds, where I define some very inefficient sine & logarithm functions to feed into the Box-Muller method, because it felt like fun to really write a botec tool really from scratch.
 
-I was very surprised that Node/Squiggle code was almost as fast as the raw C code. For the Python code, it's possible that the lack of speed is more a function of me not being as familiar with Python. It's also very possible that the code would run faster with [PyPy](https://doc.pypy.org)
- 
 ## Languages I may add later
 
-- Julia (TuringML) 
-- Rust
-- Lisp
+- [ ] Julia (TuringML) 
+- [ ] Rust
+- [ ] Lisp
+- [ ] Stan
+- [ ] Go 
+- [ ] Zig
+- [ ] Forth
 - ... and suggestions welcome
-- Stan
 
 ## Roadmap
 

nim/hardcore/samples.nim

@@ -29,7 +29,7 @@ proc sine(x: float): float =
 
 ## Arithmetic-geomtric mean
 proc ag(x: float, y: float): float = 
-  let n = 16 # just some high number
+  let n = 32 # just some high number
   var a = (x + y)/2.0
   var b = sqrt(x * y)
   for i in 0..n:
@@ -41,7 +41,7 @@ proc ag(x: float, y: float): float =
 ## Find m such that x * 2^m > 2^precision/2
 proc find_m(x:float): float = 
   var m = 0.0;
-  let precision = 32 # bits
+  let precision = 64 # bits
   let c = pow(2.0, precision.float / 2.0)
   while x * pow(2.0, m) < c:
     m = m + 1

nim/makefile

@@ -8,4 +8,5 @@ run: samples
 	./samples $(VERBOSE)
 
 examine: samples
-	nim c $(VERBOSE) -d:release samples.nim && time ./samples $(VERBOSE)
+	nim c $(VERBOSE) -d:release samples.nim && time ./samples $(VERBOSE) && echo
+	nim c $(VERBOSE) -d:danger samples.nim && time ./samples $(VERBOSE)

time.txt

@@ -36,3 +36,18 @@ real    0m7,000s
 user    0m6,944s
 sys     0m0,052s
 
+## Nim
+
+nim c --verbosity:0 -d:release samples.nim && time ./samples --verbosity:0 && echo
+0.8873815480558296
+
+real    0m0.183s
+user    0m0.150s
+sys     0m0.032s
+
+nim c --verbosity:0 -d:danger samples.nim && time ./samples --verbosity:0
+0.8886260086130379
+
+real    0m0.157s
+user    0m0.136s
+sys     0m0.020s