add gaussian-column

src/matrix/auto.clj

@@ -27,7 +27,8 @@
 ;;   "Takes a matrix and a list of operations and returns a seq of matrices"
 ;;   )
 
-;; (defn gaussian-top-op
-;;   [m]
-;;   "Takes a matrix and returns the op required to gaussian-eliminate the top"
-;;   {:n})
+(defn gaussian-column
+  [m col]
+  (cons {:mul-row col :by (/ 1 (at m col col))}
+        (for [y (range (inc col) (matrix-height m))]
+          {:add-row col :times (- (at m col y)) :to-row y})))

src/matrix/base.clj

@@ -89,3 +89,8 @@
               m
               (:by      inner)
               (:mul-row inner))))))
+
+(defn at
+  "Returns the number at x y in a matrix"
+  [m x y]
+  (get (get m y) x))

src/matrix/render.clj

@@ -167,7 +167,7 @@
     (str n
          "R" (shrink-number (:add-row op))
          " + "
-         "R" (shrink-number (:to op)))))
+         "R" (shrink-number (:to-row op)))))
 
 (defn pretty-row-op
   "Returns a pretty string of a row operation"

src/matrix/spec.clj

@@ -12,7 +12,7 @@
   (spec/map-of #{:swap :with} number?))
 
 (spec/def ::add
-  (spec/map-of #{:add-row :times :to} number?))
+  (spec/map-of #{:add-row :times :to-row} number?))
 
 (spec/def ::mul
   (spec/map-of #{:mul-row :by} number?))