uploaded all materials

hw4/feedback/switchsign.m

@@ -0,0 +1,17 @@
+% cursed
+		% lmao
+% basically - I take pairs of adjacent values on the vector `x` and add them
+% 	together. These sums are then checked against both members of the pair,
+%	and if either member is *larger* than the sum, that indicates a sign change
+%	since one of the values acted as a subtractor.
+%	"Glue" is added in the comparison stage, to skew ONLY on cases where
+%	we are comparing zero to zero (origin case). Its really a rounding error otherwise. lol
+% The front is padded w/ a zero.
+function ret = switchsign(x)
+	sum_check = x(1:end-1) + x(2:end); 
+	ret = [0, ( abs(sum_check) < abs(x(1:end-1)+1e-7) ) | ( abs(sum_check) < abs(x(2:end)+1e-7) ) ];
+end
+		% <-.01> works here (this is insane), but technically has an
+		% error: calling `switchsign([-1 2 1 0 1 -3])` (the example i
+		% gave) returns `[0 1 0 1 1 1]` rather than `[0 1 0 0 0 1]`.
+		% not that that really matters. sorry...