Data commit

Task/Display-a-linear-combination/Jq/display-a-linear-combination-1.jq

@@ -0,0 +1,29 @@
+def linearCombo:
+  reduce to_entries[] as {key: $k,value: $v} ("";
+     if $v == 0 then .
+     else
+        (if $v < 0 and length==0 then   "-"
+         elif $v < 0 then               " - "
+         elif $v > 0 and length==0 then ""
+         else                           " + "
+         end) as $sign
+        | ($v|fabs) as $av
+        | (if ($av == 1) then "" else "\($av)*" end) as $coeff
+        | .  + "\($sign)\($coeff)e\($k)"
+     end)
+  | if length==0 then "0" else . end ;
+
+# The exercise
+def lpad($len): tostring | ($len - length) as $l | (" " * $l)[:$l] + .;
+
+[1, 2, 3],
+[0, 1, 2, 3],
+[1, 0, 3, 4],
+[1, 2, 0],
+[0, 0, 0],
+[0],
+[1, 1, 1],
+[-1, -1, -1],
+[-1, -2, 0, -3],
+[-1]
+| "\(lpad(15)) => \(linearCombo)"

Task/Display-a-linear-combination/Jq/display-a-linear-combination-2.jq

@@ -0,0 +1,10 @@
+        [1,2,3] => e0 + 2*e1 + 3*e2
+      [0,1,2,3] => e1 + 2*e2 + 3*e3
+      [1,0,3,4] => e0 + 3*e2 + 4*e3
+        [1,2,0] => e0 + 2*e1
+        [0,0,0] => 0
+            [0] => 0
+        [1,1,1] => e0 + e1 + e2
+     [-1,-1,-1] => -e0 - e1 - e2
+   [-1,-2,0,-3] => -e0 - 2*e1 - 3*e3
+           [-1] => -e0