The Hylos notebook is not ready for public yet.

This commit is contained in:
Simon Forman
2018-06-08 13:05:59 -07:00
parent f5fe7d9726
commit b98e9f2107
18 changed files with 463 additions and 2825 deletions
+30 -11
View File
@@ -55,13 +55,6 @@ The generator can be written as:
1 [dup 23 over / + 2 /] make_generator
```python
define('codireco == cons dip rest cons')
define('make_generator == [codireco] ccons')
define('ccons == cons cons')
```
```python
define('gsra == 1 swap [over / + 2 /] cons [dup] swoncat make_generator')
```
@@ -86,11 +79,11 @@ J('23 gsra 6 [x popd] times first sqr')
## Finding Consecutive Approximations within a Tolerance
From ["Why Functional Programming Matters" by John Hughes](https://www.cs.kent.ac.uk/people/staff/dat/miranda/whyfp90.pdf):
> The remainder of a square root finder is a function _within_, which takes a tolerance and a list of approximations and looks down the list for two successive approximations that differ by no more than the given tolerance.
From ["Why Functional Programming Matters" by John Hughes](https://www.cs.kent.ac.uk/people/staff/dat/miranda/whyfp90.pdf)
(And note that by “list” he means a lazily-evaluated list.)
Using the _output_ `[a G]` of the above generator for square root approximations, and further assuming that the first term a has been generated already and epsilon ε is handy on the stack...
@@ -137,8 +130,8 @@ define('_within_B == roll< popop first')
a [b G] ε R0 [within] R1
1. Discard a.
2. Use x combinator to generate next term from G.
3. Run within with `i` (it is a `primrec` function.)
2. Use `x` combinator to generate next term from `G`.
3. Run `within` with `i` (it is a `primrec` function.)
Pretty straightforward:
@@ -169,6 +162,16 @@ define('within == x 0.000000001 [_within_P] [_within_B] [_within_R] primrec')
define('sqrt == gsra within')
```
Try it out...
```python
J('36 sqrt')
```
6.0
```python
J('23 sqrt')
@@ -177,6 +180,8 @@ J('23 sqrt')
4.795831523312719
Check it.
```python
4.795831523312719**2
@@ -188,3 +193,17 @@ J('23 sqrt')
22.999999999999996
```python
from math import sqrt
sqrt(23)
```
4.795831523312719