deprecate common lisp solutions and write c; it's too much effort to keep up with the requirements for an archive.

23 files changed, 182 insertions, 360 deletions

diff --git a/src/approx,derivative.lisp b/src/approx,derivative.lisp
deleted file mode 100644
index 631a5c0..0000000
--- a/src/approx,derivative.lisp
+++ /dev/null
@@ -1,25 +0,0 @@
-(in-package :lizfcm.approx)
-
-(defun central-derivative-at (f x &optional (delta 0.01))
-  (let* ((x2 (+ x delta))
-         (x1 (- x delta))
-         (y2 (apply f (list x2)))
-         (y1 (apply f (list x1))))
-    (/ (- y2 y1)
-       (- x2 x1))))
-
-(defun forward-derivative-at (f x &optional (delta 0.01))
-  (let* ((x2 (+ x delta))
-         (x1 x)
-         (y2 (apply f (list x2)))
-         (y1 (apply f (list x1))))
-    (/ (- y2 y1)
-       (- x2 x1))))
-
-(defun backward-derivative-at (f x &optional (delta 0.01))
-  (let* ((x2 x)
-         (x1 (- x delta))
-         (y2 (apply f (list x2)))
-         (y1 (apply f (list x1))))
-    (/ (- y2 y1)
-       (- x2 x1))))
diff --git a/src/approx,maceps.lisp b/src/approx,maceps.lisp
deleted file mode 100644
index e2738e4..0000000
--- a/src/approx,maceps.lisp
+++ /dev/null
@@ -1,12 +0,0 @@
-(in-package :lizfcm.approx)
-
-(defun compute-maceps (f a init)
-  (let ((h init)
-        (err init))
-    (loop collect (list a h err)
-          do
-          (setf h (/ h 2)
-                err (abs (- (funcall f (+ a h))
-                            (funcall f a))))
-          while (> err 0))))
-
diff --git a/src/approx,package.lisp b/src/approx,package.lisp
deleted file mode 100644
index a0eac80..0000000
--- a/src/approx,package.lisp
+++ /dev/null
@@ -1,7 +0,0 @@
-(in-package :cl-user)
-(defpackage lizfcm.approx
-  (:use :cl)
-  (:export :central-derivative-at
-           :forward-derivative-at
-           :backward-derivative-at
-           :compute-maceps))
diff --git a/src/approx_derivative.c b/src/approx_derivative.c
new file mode 100644
index 0000000..b33a208
--- /dev/null
+++ b/src/approx_derivative.c
@@ -0,0 +1,38 @@
+#include "lizfcm.h"
+#include <assert.h>
+
+double central_derivative_at(double (*f)(double), double a, double h) {
+  assert(h > 0);
+
+  double x2 = a + h;
+  double x1 = a - h;
+
+  double y2 = (*f)(x2);
+  double y1 = (*f)(x1);
+
+  return (y2 - y1) / (x2 - x1);
+}
+
+double forward_derivative_at(double (*f)(double), double a, double h) {
+  assert(h > 0);
+
+  double x2 = a + h;
+  double x1 = a;
+
+  double y2 = (*f)(x2);
+  double y1 = (*f)(x1);
+
+  return (y2 - y1) / (x2 - x1);
+}
+
+double backward_derivative_at(double (*f)(double), double a, double h) {
+  assert(h > 0);
+
+  double x2 = a;
+  double x1 = a - h;
+
+  double y2 = (*f)(x2);
+  double y1 = (*f)(x1);
+
+  return (y2 - y1) / (x2 - x1);
+}
diff --git a/src/lin.c b/src/lin.c
new file mode 100644
index 0000000..2df6f28
--- /dev/null
+++ b/src/lin.c
@@ -0,0 +1,19 @@
+#include "lizfcm.h"
+#include <assert.h>
+
+Line *least_squares_lin_reg(Array_double *x, Array_double *y) {
+  assert(x->size == y->size);
+
+  uint64_t n = x->size;
+  double sum_x = sum_v(x);
+  double sum_y = sum_v(y);
+  double sum_xy = dot_v(x, y);
+  double sum_xx = dot_v(x, x);
+  double denom = ((n * sum_xx) - (sum_x * sum_x));
+
+  Line *line = malloc(sizeof(Line));
+  line->m = ((sum_xy * n) - (sum_x * sum_y)) / denom;
+  line->a = ((sum_y * sum_xx) - (sum_x * sum_xy)) / denom;
+
+  return line;
+}
diff --git a/src/lizfcm.asd b/src/lizfcm.asd
deleted file mode 100644
index 0096257..0000000
--- a/src/lizfcm.asd
+++ /dev/null
@@ -1,33 +0,0 @@
-(asdf:defsystem "lizfcm"
-                :version "0.1.0"
-                :author "Elizabeth Hunt"
-                :license "MIT"
-                :components
-                ((:file "utils,within-range" :depends-on ("utils,package"))
-                 (:file "utils,table" :depends-on ("utils,package"))
-                 (:file "utils,package")
-                 (:file "approx,maceps" :depends-on ("approx,package"))
-                 (:file "approx,derivative" :depends-on ("approx,package"))
-                 (:file "approx,package")
-                 (:file "vector,least-squares")
-                 (:file "vector,distance" :depends-on ("vector,norm" "vector,package"))
-                 (:file "vector,norm" :depends-on ("vector,package"))
-                 (:file "vector,package")))
-
-
-(asdf:defsystem "lizfcm/tests"
-                :author "Elizabeth Hunt"
-                :license "MIT"
-                :depends-on
-                (:fiveam
-                  :lizfcm)
-                :components
-                ((:file "tests,table" :depends-on ("tests,suite"))
-                 (:file "tests,maceps" :depends-on ("tests,suite"))
-                 (:file "tests,approx" :depends-on ("tests,suite"))
-                 (:file "tests,vector" :depends-on ("tests,suite"))
-                 (:file "tests,suite"))
-                :perform
-                (asdf:test-op (o c) (uiop:symbol-call
-                                      :fiveam :run!
-                                      (uiop:find-symbol* :lizfcm-test-suite :lizfcm/tests))))
diff --git a/src/maceps.c b/src/maceps.c
new file mode 100644
index 0000000..23bc9db
--- /dev/null
+++ b/src/maceps.c
@@ -0,0 +1,28 @@
+#include "lizfcm.h"
+#include <math.h>
+
+float smaceps() {
+  float one = 1.0;
+  float machine_epsilon = 1.0;
+  float one_approx = one + machine_epsilon;
+
+  while (fabsf(one_approx - one) > 0) {
+    machine_epsilon /= 2;
+    one_approx = one + machine_epsilon;
+  }
+
+  return machine_epsilon;
+}
+
+double dmaceps() {
+  double one = 1.0;
+  double machine_epsilon = 1.0;
+  double one_approx = one + machine_epsilon;
+
+  while (fabs(one_approx - one) > 0) {
+    machine_epsilon /= 2;
+    one_approx = one + machine_epsilon;
+  }
+
+  return machine_epsilon;
+}
diff --git a/src/main.c b/src/main.c
new file mode 100644
index 0000000..6bb704a
--- /dev/null
+++ b/src/main.c
@@ -0,0 +1,7 @@
+#include "lizfcm.h"
+#include <stdio.h>
+
+int main() {
+  printf("hello, from lizfcm!\n");
+  return 0;
+}
diff --git a/src/main.lisp b/src/main.lisp
deleted file mode 100644
index 7a8b455..0000000
--- a/src/main.lisp
+++ /dev/null
@@ -1,60 +0,0 @@
-(load "lizfcm.asd")
-(ql:quickload :lizfcm)
-
-;; this is a collection showcasing the library developed for math4610, required
-;; from the Shared Library definition
-
-(defun smaceps ()
-  (cadar (last (lizfcm.approx:compute-maceps
-                 (lambda (x) x) 1.0 1.0))))
-
-(defun dmaceps ()
-  (cadar (last (lizfcm.approx:compute-maceps
-                 (lambda (x) x) 1.0d0 1.0d0))))
-
-(defun l2-norm (v)
-  (let ((2-norm (lizfcm.vector:p-norm 2)))
-    (funcall 2-norm v)))
-
-(defun l1-norm (v)
-  (let ((1-norm (lizfcm.vector:p-norm 1)))
-    (funcall 1-norm v)))
-
-(defun linf-norm (v)
-  (lizfcm.vector:max-norm v))
-
-(defun l2-distance (v1 v2)
-  (let ((2-norm (lizfcm.vector:p-norm 2)))
-    (lizfcm.vector:distance v1 v2 2-norm)))
-
-(defun l1-distance (v1 v2)
-  (let ((1-norm (lizfcm.vector:p-norm 1)))
-    (lizfcm.vector:distance v1 v2 1-norm)))
-
-(defun linf-distance (v1 v2)
-  (lizfcm.vector:distance v1 v2 'lizfcm.vector:max-norm))
-
-(defun f (x)
-  (/ (- x 1) (+ x 1)))
-
-(defun fprime (x)
-  (/ 2 (expt (+ x 1) 2)))
-
-(defmacro showcase (s-expr)
-  `(format t "~a = ~a~%" ,(format nil "~a" s-expr) ,s-expr))
-
-(defun main ()
-  (showcase (smaceps))
-  (showcase (dmaceps))
-  (showcase (l2-norm '(1 2)))
-  (showcase (l1-norm '(1 2)))
-  (showcase (linf-norm '(1 2)))
-  (showcase (l1-distance '(1 2) '(-3 4)))
-  (showcase (l2-distance '(1 2) '(-3 4)))
-  (showcase (linf-distance '(1 2) '(-3 4)))
-  (showcase (lizfcm.vector:least-squares-reg '(1 2 3 4 5 6 7)
-                                             '(0.5 3 2 3.5 5 6 7.5)))
-  (showcase (lizfcm.approx:forward-derivative-at 'f 1 0.00001))
-  (showcase (lizfcm.approx:central-derivative-at 'f 1 0.00001))
-  (showcase (lizfcm.approx:backward-derivative-at 'f 1 0.00001)))
-
diff --git a/src/tests,approx.lisp b/src/tests,approx.lisp
deleted file mode 100644
index 678ff8c..0000000
--- a/src/tests,approx.lisp
+++ /dev/null
@@ -1,48 +0,0 @@
-(defpackage lizfcm/tests.approx
-  (:use :cl
-        :fiveam
-        :lizfcm.approx
-        :lizfcm.utils
-        :lizfcm/tests)
-  (:export :approx-suite))
-(in-package :lizfcm/tests.approx)
-
-(def-suite approx-suite
-           :in lizfcm-test-suite)
-(in-suite approx-suite)
-
-(test central-derivative-at
-      :description "derivative at is within bounds"
-      (let ((f (lambda (x) (* x x)))
-            (x 2)
-            (accepted-delta 0.02)
-            (f-prime-at-x 4)
-            (delta 0.01))
-        (is (within-range-p
-              (central-derivative-at f x delta)
-              f-prime-at-x
-              accepted-delta))))
-
-(test fwd-derivative-at
-      :description "forward derivative at is within bounds"
-      (let ((f (lambda (x) (* x x)))
-            (x 2)
-            (accepted-delta 0.02)
-            (f-prime-at-x 4)
-            (delta 0.01))
-        (is (within-range-p
-              (forward-derivative-at f x delta)
-              f-prime-at-x
-              accepted-delta))))
-
-(test bwd-derivative-at
-      :description "backward derivative at is within bounds"
-      (let ((f (lambda (x) (* x x)))
-            (x 2)
-            (accepted-delta 0.02)
-            (f-prime-at-x 4)
-            (delta 0.01))
-        (is (within-range-p
-              (backward-derivative-at f x delta)
-              f-prime-at-x
-              accepted-delta))))
diff --git a/src/tests,maceps.lisp b/src/tests,maceps.lisp
deleted file mode 100644
index cd5ced9..0000000
--- a/src/tests,maceps.lisp
+++ /dev/null
@@ -1,27 +0,0 @@
-(defpackage lizfcm/tests.maceps
-  (:use :cl
-        :fiveam
-        :lizfcm.approx
-        :lizfcm.utils
-        :lizfcm/tests)
-  (:export :approx-suite))
-(in-package :lizfcm/tests.maceps)
-
-(def-suite maceps-suite
-           :in lizfcm-test-suite)
-(in-suite maceps-suite)
-
-(test maceps
-      :description "double precision provides precision about (mac eps of single precision) squared"
-      (let* ((maceps-computation-double (compute-maceps (lambda (x) x)
-                                                        1.0d0
-                                                        1.0d0))
-             (maceps-computation-single (compute-maceps (lambda (x) x)
-                                                        1.0
-                                                        1.0))
-             (last-double-h (cadar (last maceps-computation-double)))
-             (last-single-h (cadar (last maceps-computation-single))))
-        (is (within-range-p
-              (- last-double-h (* last-single-h last-single-h))
-              0
-              last-single-h))))
diff --git a/src/tests,suite.lisp b/src/tests,suite.lisp
deleted file mode 100644
index e23cfaf..0000000
--- a/src/tests,suite.lisp
+++ /dev/null
@@ -1,10 +0,0 @@
-(in-package :cl-user)
-(defpackage lizfcm/tests
-  (:use :cl
-        :fiveam)
-  (:export :run!
-           :lizfcm-test-suite))
-(in-package :lizfcm/tests)
-
-(def-suite lizfcm-test-suite
-    :description "The ultimate parent test suite")
diff --git a/src/tests,table.lisp b/src/tests,table.lisp
deleted file mode 100644
index 33d4e86..0000000
--- a/src/tests,table.lisp
+++ /dev/null
@@ -1,31 +0,0 @@
-(defpackage lizfcm/tests.table
-  (:use :cl
-        :fiveam
-        :lizfcm.utils
-        :lizfcm/tests)
-  (:export :approx-suite))
-(in-package :lizfcm/tests.table)
-
-(def-suite table-suite
-           :in lizfcm-test-suite)
-(in-suite table-suite)
-
-(defun fib (n)
-  (cond ((< n 2) n)
-        (t (+ (fib (- n 1)) (fib (- n 2))))))
-
-(test table-of-fib-vals
-      :description "table generates correctly"
-      (let* ((headers '("n" "fib(n)"))
-             (n-values '((1) (2) (3) (4)))
-             (expected `(("n" "fib(n)")
-                         (1 ,(fib 1))
-                         (2 ,(fib 2))
-                         (3 ,(fib 3))
-                         (4 ,(fib 4))))
-             (tabled (lizfcm.utils:table (:headers headers
-                                                   :domain-order (n)
-                                                   :domain-values n-values)
-                                         (fib n))))
-        (is (equal expected tabled))))
-
diff --git a/src/tests,vector.lisp b/src/tests,vector.lisp
deleted file mode 100644
index 6edb1ac..0000000
--- a/src/tests,vector.lisp
+++ /dev/null
@@ -1,42 +0,0 @@
-(defpackage lizfcm/tests.vector
-  (:use :cl
-        :fiveam
-        :lizfcm.vector
-        :lizfcm.utils
-        :lizfcm/tests)
-  (:export :vector-suite))
-(in-package :lizfcm/tests.vector)
-
-(def-suite vector-suite
-           :in lizfcm-test-suite)
-(in-suite vector-suite)
-
-(test p-norm
-      :description "computes p-norm"
-      (let ((v '(1 1))
-            (length (sqrt 2))
-            (2-norm (p-norm 2)))
-        (is (within-range-p (funcall 2-norm v)
-                            length
-                            0.00001))))
-
-(test vector-distance
-      :description "computes distance via norm"
-      (let ((v1 '(0 0))
-            (v2 '(1 1))
-            (dist (sqrt 2)))
-        (is (within-range-p (distance v1 v2 (p-norm 2))
-                            dist
-                            0.00001))))
-
-(test least-squares
-      :description "least squares is correct enough"
-      (let ((x '(0 1 2 3 4))
-            (y '(1 2 3 4 5)))
-        (destructuring-bind (m b) (lizfcm.vector:least-squares-reg x y)
-          (is (within-range-p m 1 0.00001))
-          (is (within-range-p b 1 0.00001))))
-      (let ((x '(1 2 3 4 5 6 7))
-            (y '(0.5 3 2 3.5 5 6 7.5)))
-        (destructuring-bind (m b) (lizfcm.vector:least-squares-reg x y)
-          (is (within-range-p m 1 0.3))))) ;; just a guestimate for best fit
diff --git a/src/utils,package.lisp b/src/utils,package.lisp
deleted file mode 100644
index bdd5589..0000000
--- a/src/utils,package.lisp
+++ /dev/null
@@ -1,5 +0,0 @@
-(in-package :cl-user)
-(defpackage lizfcm.utils
-  (:use :cl)
-  (:export :within-range-p
-           :table))
diff --git a/src/utils,table.lisp b/src/utils,table.lisp
deleted file mode 100644
index e96f37b..0000000
--- a/src/utils,table.lisp
+++ /dev/null
@@ -1,11 +0,0 @@
-(in-package :lizfcm.utils)
-
-(defmacro table ((&key headers domain-order domain-values) &body body)
-  `(cons
-     ,headers
-     (mapcar (lambda (tuple)
-               (destructuring-bind ,domain-order tuple
-                 (append tuple
-                         (list
-                           ,@body))))
-             ,domain-values)))
diff --git a/src/utils,within-range.lisp b/src/utils,within-range.lisp
deleted file mode 100644
index 9a0b762..0000000
--- a/src/utils,within-range.lisp
+++ /dev/null
@@ -1,5 +0,0 @@
-(in-package :lizfcm.utils)
-
-(defun within-range-p (x true-value delta)
-  (and (< x (+ true-value delta))
-       (> x (- true-value delta))))
diff --git a/src/vector,distance.lisp b/src/vector,distance.lisp
deleted file mode 100644
index 74631ce..0000000
--- a/src/vector,distance.lisp
+++ /dev/null
@@ -1,6 +0,0 @@
-(in-package :lizfcm.vector)
-
-(defun distance (v1 v2 norm)
-  (let* ((d (mapcar #'- v1 v2))
-         (length (funcall norm d)))
-    length))
diff --git a/src/vector,least-squares-reg.lisp b/src/vector,least-squares-reg.lisp
deleted file mode 100644
index 1c7272c..0000000
--- a/src/vector,least-squares-reg.lisp
+++ /dev/null
@@ -1,2 +0,0 @@
-(in-package :lizfcm.vector)
-
diff --git a/src/vector,least-squares.lisp b/src/vector,least-squares.lisp
deleted file mode 100644
index 687af32..0000000
--- a/src/vector,least-squares.lisp
+++ /dev/null
@@ -1,14 +0,0 @@
-(in-package :lizfcm.vector)
-
-(defun least-squares-reg (x y)
-  (let* ((n (length x))
-         (sum-y (reduce #'+ y))
-         (sum-x (reduce #'+ x))
-         (sum-xy (reduce #'+ (mapcar #'* x y)))
-         (sum-xsquared (reduce #'+ (mapcar #'* x x)))
-         (b (/ (- (* sum-y sum-xsquared) (* sum-x sum-xy))
-               (- (* n sum-xsquared) (* sum-x sum-x))))
-         (a (/ (- (* n sum-xy) (* sum-x sum-y))
-               (- (* n sum-xsquared) (* sum-x sum-x)))))
-    (list a b)))
-
diff --git a/src/vector,norm.lisp b/src/vector,norm.lisp
deleted file mode 100644
index aa51bce..0000000
--- a/src/vector,norm.lisp
+++ /dev/null
@@ -1,14 +0,0 @@
-(in-package :lizfcm.vector)
-
-(defun p-norm (p)
-  (lambda (v)
-    (expt
-      (reduce #'+
-              (mapcar (lambda (x)
-                        (abs
-                          (expt x p)))
-                      v))
-      (/ 1 p))))
-
-(defun max-norm (v)
-  (reduce #'max v))
diff --git a/src/vector,package.lisp b/src/vector,package.lisp
deleted file mode 100644
index f491908..0000000
--- a/src/vector,package.lisp
+++ /dev/null
@@ -1,8 +0,0 @@
-(in-package :cl-user)
-(defpackage lizfcm.vector
-  (:use :cl)
-  (:export
-    :p-norm
-    :max-norm
-    :distance
-    :least-squares-reg))
diff --git a/src/vector.c b/src/vector.c
new file mode 100644
index 0000000..61692e1
--- /dev/null
+++ b/src/vector.c
@@ -0,0 +1,90 @@
+#include "lizfcm.h"
+#include <assert.h>
+#include <float.h>
+#include <math.h>
+#include <stdio.h>
+
+double l2_norm(Array_double *v) {
+  double norm = 0;
+  for (size_t i = 0; i < v->size; ++i)
+    norm += v->data[i] * v->data[i];
+  return sqrt(norm);
+}
+
+double l1_norm(Array_double *v) {
+  double sum = 0;
+  for (size_t i = 0; i < v->size; ++i)
+    sum += fabs(v->data[i]);
+  return sum;
+}
+
+double linf_norm(Array_double *v) {
+  double max = -DBL_MAX;
+  for (size_t i = 0; i < v->size; ++i)
+    max = c_max(v->data[i], max);
+  return max;
+}
+
+Array_double *minus_v(Array_double *v1, Array_double *v2) {
+  assert(v1->size == v2->size);
+
+  Array_double *sub = InitArrayWithSize(double, v1->size, 0);
+  for (size_t i = 0; i < v1->size; i++)
+    sub->data[i] = v1->data[i] - v2->data[i];
+  return sub;
+}
+
+double sum_v(Array_double *v) {
+  double sum = 0;
+  for (size_t i = 0; i < v->size; i++)
+    sum += v->data[i];
+  return sum;
+}
+
+Array_double *add_v(Array_double *v1, Array_double *v2) {
+  assert(v1->size == v2->size);
+
+  Array_double *sum = InitArrayWithSize(double, v1->size, 0);
+  for (size_t i = 0; i < v1->size; i++)
+    sum->data[i] = v1->data[i] + v2->data[i];
+  return sum;
+}
+
+double dot_v(Array_double *v1, Array_double *v2) {
+  assert(v1->size == v2->size);
+
+  double dot = 0;
+  for (size_t i = 0; i < v1->size; i++)
+    dot += v1->data[i] * v2->data[i];
+  return dot;
+}
+
+double l2_distance(Array_double *v1, Array_double *v2) {
+  Array_double *minus = minus_v(v1, v2);
+  double dist = l2_norm(minus);
+  free(minus);
+  return dist;
+}
+
+double l1_distance(Array_double *v1, Array_double *v2) {
+  Array_double *minus = minus_v(v1, v2);
+  double dist = l1_norm(minus);
+  free(minus);
+  return dist;
+}
+
+double linf_distance(Array_double *v1, Array_double *v2) {
+  Array_double *minus = minus_v(v1, v2);
+  double dist = linf_norm(minus);
+  free(minus);
+  return dist;
+}
+
+void format_vector_into(Array_double *v, char *s) {
+  sprintf(s, "");
+  if (v->size == 0)
+    sprintf(s, "empty");
+
+  for (size_t i = 0; i < v->size; ++i)
+    sprintf(s, "%s %f,", s, v->data[i]);
+}