# how does a diff operation works for relational and logical cases with arrays ?

1 view (last 30 days)
mayank ghugretkar on 7 Jun 2019
Answered: Star Strider on 7 Jun 2019
i was trying to work with diff operator after trying out sum[1 2 4 6]
diff([14 5 6 14 32])
ans=
-9 1 8 18
above statement is understandable.
diff([14 5 6 14 32]==14)
ans=
-1 0 1 -1
this i can't understand !
how is this working???

madhan ravi on 7 Jun 2019
A = [14 5 6 14 32]==14 % Split it into two lines
diff(A)

Star Strider on 7 Jun 2019
The argument creates a logical array:
Lv = [14 5 6 14 32]==14
Lv =
1×5 logical array
1 0 0 1 0
and logical arrayss become numeric when you do calculations with them:
D = diff(Lv)
D =
-1 0 1 -1
Similarly:
v = [14 5 6 14 32];
LogicalIndexing = v(Lv)
Multiplication = v .* Lv
LogicalIndexing =
14 14
Multiplication =
14 0 0 14 0

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