futhark, gnuplot updates

azimut · azimut · commit 6ab678c9635b · 2025-09-30T19:53:15.000-03:00
diff --git a/ai/books.org b/ai/books.org
@@ -109,27 +109,27 @@ We try to find the line that more closely approximates the relationship.
 **** code: pizzas per reservations
 
 #+begin_src python
-  x, y = np.loadtxt("pizza.txt", skiprows=1, unpack=true)
+  X, Y = np.loadtxt("pizza.txt", skiprows=1, unpack=true)
 
   # x = input var, restaurant reservations
   # w = weight
-  def predict(x, w): # our model
-      return x * w
+  def predict(X, w): # our model
+      return X * w
 
   # y = ground truth, pizzas bought
-  def loss(x, y, w): # = Mean Squared Error
-      return np.average((predict(x,w) - y) ** 2)
+  def loss(X, Y, w): # = Mean Squared Error
+      return np.average((predict(X,w) - Y) ** 2)
 
   # Returns a new w(eight)
   # lr = learning rate, step
-  def train(x, y, iterations, lr):
+  def train(X, Y, iterations, lr):
       w = 0 # arbitrary init value
       for i in range(iterations):
-          current_loss = loss(x, y, w)
+          current_loss = loss(X, Y, w)
           print("iteration %4d => loss: %.6f" % (i, current_loss))
-          if loss(x, y, w + lr) < current_loss:
+          if loss(X, Y, w + lr) < current_loss:
               w += lr
-          elif loss(x, y, w - lr) < current_loss:
+          elif loss(X, Y, w - lr) < current_loss:
               w -= lr
           else:
               return w
@@ -139,23 +139,23 @@ We try to find the line that more closely approximates the relationship.
 **** code: adding a bias
 
 #+begin_src python
-  def predict(x, w, b): # our model
+  def predict(X, w, b): # our model
       return x * w + b
 
-  def loss(x, y, w, b): # Mean Squared Error
-      return np.average((predict(x,w,b) - y) ** 2)
+  def loss(X, Y, w, b): # Mean Squared Error
+      return np.average((predict(X,w,b) - Y) ** 2)
 
-  def train(x, y, iterations, lr):
+  def train(X, Y, iterations, lr):
       w = b = 0
       for i in range(iterations):
-          current_loss = loss(x, y, w, b)
-          if   loss(x,y,w+lr,b) < current_loss:
+          current_loss = loss(X, Y, w, b)
+          if   loss(X,Y,w+lr,b) < current_loss:
               w += lr
-          elif loss(x,y,w-lr,b) < current_loss:
+          elif loss(X,Y,w-lr,b) < current_loss:
               w -= lr
-          elif loss(x,y,w,b+lr) < current_loss:
+          elif loss(X,Y,w,b+lr) < current_loss:
               b += lr
-          elif loss(x,y,w,b-lr) < current_loss:
+          elif loss(X,Y,w,b-lr) < current_loss:
               b -= lr
           else:
               return w, b
@@ -175,7 +175,10 @@ We try to find the line that more closely approximates the relationship.
   plt.yticks(fontsize=15)
   plt.xlabel("reservations", fontsize=30)
   plt.ylabel("pizza", fontsize=30)
-  x, y = np.loadtxt("pizza.txt", skiprows=1, unpack=true)
+  X, Y = np.loadtxt("pizza.txt", skiprows=1, unpack=true)
+  w = train(X,Y,iterations=1000,lr=0.01)
+  print("w=%.3f" % w)
+  print("Prediction: x=%d => y=%.2f" % (20, predict(20,w)))
   plt.plot(x,y,"bo")
   plt.show()
 #+end_src
@@ -186,7 +189,7 @@ We try to find the line that more closely approximates the relationship.
 
 - Problems with our current =train()=
   1) doesn't scale well (cpu/time) when adding new _hyperparameters_ (INPUTS)
-  2) is NOT precise, since _hyperparameters_ are defined in *lr* terms
+  2) is NOT precise, since _hyperparameters_ are defined in *lr* (learning rate) terms
 
 - observation:
   - a plot of loss(), when b=0, looks like a U curve
diff --git a/languages/compiled/ml/futhark/self.org b/languages/compiled/ml/futhark/self.org
@@ -40,12 +40,12 @@
 * language
 
 #+begin_src futhark
-  def average (xs: []f64) =
-    reduce (+) 0 xs / f64.i64 (length xs)
+  def main (x: []i32) (y: []i32): i32 =
+    reduce (+) 0 (map2 (*) x y)
 #+end_src
 
-- if you define a function called =main=, it will read STDIN
 - reference https://futhark.readthedocs.io/en/stable/language-reference.html
+- if you define a function called =main=, it will read STDIN
 - eager evaluated (not lazy)
 - one pass compiler, no recursive or circular definitions
 - no syntactically significant identation
@@ -58,15 +58,19 @@
 - no recursive functions are supported
 - *loop* supports pattern matching
 - can express equivalent tail-recursive functions
+- returns final PATTERN value
 
 #+begin_src futhark
-  -- returns final PATTERN value
-  loop x for i < n do     -- elided if an "x" is already in scope
-  loop (x=1) for i < n do -- initializes PATTERN, end condition
-    x * (i+1)             -- new value to bind PATTERN to
+  loop x       -- elided if an "x" is already in scope
+  for i < n do
 
-  -- same but gives less info to the compiler
-  loop (x=1) while x < bound do
+  loop (x = 1)   -- initial bindings of PATTERN
+  for i < n do -- end condition, "i++" on each iteration
+    x * (i+1)  -- new value to bind PATTERN
+
+  -- gives less info to the compiler
+  loop (x = 1)
+  while x < bound do
     x * 2
 #+end_src
 
@@ -102,10 +106,14 @@
 
 ** types
 
+https://futhark-lang.org/examples/sum-types.html
+
 #+CAPTION: type abbreviation
 #+begin_src futhark
   type complex = (f64,f64)
   type intvec [n] = [n]i32 -- def x: intvec [3] = [1,2,3]
+  type dir = #left | #right -- sum types
+  type int_or_float = #int i32 | #float f32
 #+end_src
 
 *** simple
@@ -367,9 +375,14 @@ Giving related functionality a common abstraction.
 - https://github.com/BobMcDear/llaf/
 * tools
 - editor: emacs mode https://github.com/diku-dk/futhark-mode
+- ci: github action https://github.com/diku-dk/install-futhark
 * prebuild installation
 
 #+begin_src sh
   $ make install MANPREFIX=$HOME/.local/share/man PREFIX=$HOME/.local
   $ mandb
 #+end_src
+* gotchas
+
+- futhark-literate
+  - doesn't include constant definitions
diff --git a/terminal/tools/visualization/gnuplot/self.org b/terminal/tools/visualization/gnuplot/self.org
@@ -89,6 +89,7 @@
 |           |                                    | eg: S_min_x                 |
 |-----------+------------------------------------+-----------------------------|
 
+
 *** plot
 
 #+begin_src
@@ -126,6 +127,7 @@
   - histograms
   - filledcurves
     - [f]ill[s]tyle pattern N
+  - dots
   - points
     - pointsize N
   - lines
@@ -229,7 +231,7 @@ b              -0.890  1.000
 |             | separator comma | input separator (default: space) |
 |-------------+-----------------+----------------------------------|
 | decimalsign |        S        | "." or ","                       |
-|   samples   |        N        | sampling frequency               |
+|   samples   |      N[,N]      | sampling frequency               |
 |  [xyz]data  |      time       | tells ? axis is a date/time      |
 | timecolumn  |      N FMT      | INPUT format date on column N    |
 |   timefmt   |       FMT       | INPUT format date                |
@@ -254,11 +256,33 @@ b              -0.890  1.000
 |               |     rotate     |                                  |
 |               | START,STEP,END |                                  |
 |               |  (S N[,S N])   | custom labels S at point N       |
+|               |   font ",20"   | set font size to 20              |
 |   [xyz]tic    |  rotate by N   | rotates tic labels               |
 | [xyz][2]label |       S        | axis label                       |
 |               |  offset N[,N]  |                                  |
+|               |   font ",20"   | set font size to 20              |
 |     label     |   N at X,Y S   | puts a label at X,Y position     |
 |---------------+----------------+----------------------------------|
+*** general: splot
+|-------------+-------------+-----------------------------------|
+| dgrid3d     | N,N         | ????                              |
+| xyplane     | N           | Z value where xyplane is          |
+| +ticslevel+ | N           | " DEPRECATED                      |
+| colorbox    | -           | color range box                   |
+| pm3d        | border lw 1 | surface with lines                |
+| isosamples  | N           | splot lines draw per xz axis      |
+| view        | X,Z         | 0-180 rotation around axis        |
+| hidden3d    | -           | non translucent (disables sample) |
+|             |             | linestyle 1/2 for top/bottom      |
+|             |             | aka "hidden line removal"         |
+|-------------+-------------+-----------------------------------|
+
+#+begin_src gnuplot
+  splot f(x,y) with pm3d          # surface
+  splot f(x,y) lc pal        lw 2 # sets isolines color/thicc
+  set     lt 1 lc "seagreen" lw 3
+#+end_src
+
 *** key
 
 |-----+---------------+-------------------------------|
@@ -309,8 +333,15 @@ b              -0.890  1.000
 http://gnuplot.info/demo/pm3dcolors.html
 
 #+begin_src gnuplot
+  set palette gray
   set palette rgb 7,5,15
   set palette defined (0 0 0 0, 0.3 1 0 0, 0.6 "blue", 1 "#ffffff")
+  set palette defined (0 "blue", 0.5 "red", 1 "white")
+  set palette defined (0 "black", 0.5 "blue", 0.5 "red", 1 "white")
+  set palette cubehelix start 0 cycles -1. saturation 1
+  set palette cubehelix start 1.2 cycles -1 saturation 1
+  set palette cubehelix start pi/2 cycles -1 saturation 1
+  set palette cubehelix start pi/2 cycles -15 saturation 1
 #+end_src
 
 * snippets
