Adding the work-eqs.el file

diff --git a/common-init.el b/common-init.el
index fbdad51b38484f579ff831dbe370e7b10def922b..f311518f42ebf21faa359a5a79994899a6a9cb36 100644 (file)
--- a/common-init.el
+++ b/common-init.el
@@ -150,6 +150,8 @@ Assumes common-init is defined as a variable in the separate init."
   (interactive)
   (find-file common-init))
 
+(load-file "./work-eqs.el")
+
 ;; PUTS AND PUSHES
 (put 'upcase-region 'disabled nil)
 (put 'downcase-region 'disabled nil)

diff --git a/work-eqs.el b/work-eqs.el
new file mode 100644 (file)
index 0000000..a12d0d7
--- /dev/null
+++ b/work-eqs.el
@@ -0,0 +1,35 @@
+;; WORK (NON-EDITING) RELATED DEFUNS
+(defun square (x)
+  "Calculate the square of a value."
+  (* x x))
+
+(defun scaleval (pmax pmin emax emin &optional ai)
+  "Calculate the slope and offset given PLC Max/Min and Eng. Max/Min.
+With optional argument 'ai', also calculate a final scaled value from an input."
+  (let ((div (/ (- pmax pmin) (- emax emin))))
+    (let ((ofst (- emin (/ pmin div))))
+      (if (not (eq nil ai))
+         (let ((final (+ ofst (/ ai div))))
+           (list div ofst final))
+       (list div ofst)))))
+
+(defun cfm-circ (fpm radius)
+  "Calculate the CFM of a circular duct given fpm and radius (in)."
+  (list (* pi fpm (square (/ radius 12)))))
+
+(defun cfm-rect (fpm width height)
+  "Calculate the CFM of a circular duct given fpm, width (in) and height (in)."
+  (list (* fpm (/ width 12) (/ height 12))))
+
+(defun pid-tune (Ku Tu p-type)
+  "Use the Ziegler-Nichols method to tune a P, PI or PID loop.
+Takes Ku, Tu and p-type (P, PI, or PID) as arguments, and returns appropriate kp, ki, and kd."
+  (cond ((or (equal 'p p-type)
+            (equal 'P p-type))
+        (list (* 0.5 Ku)))
+       ((or (equal 'pi p-type)
+            (equal 'PI p-type))
+        (list (* 0.45 Ku) (/ (* 0.54 Ku) Tu)))
+       ((or (equal 'pid p-type)
+            (equal 'PID p-type))
+        (list (* 0.6 Ku) (/ (* 1.2 Ku) Tu) (/ (* 3.0 Ku Tu) 40)))))