Topic: Am I a Dummy ????

Dear Jacques,

Reading your following web page.

You say on that page:
"Let’s take now a very simple example. The angle is 0.984735 radians and we are looking for the tangent."


"The ratio Y/X = 1.50633085144 is the number we are looking for tan(0.984735)"


"Y/X = 1.190000420 / 0.789999368 = 1.506330851 which is the tangent of 0.984735"

Jacques, the following is "my" playing with the Cordic function, I think if you inspect my X and Y values, and compare with your above values, you can see how a "dummy" could be confused with this Cordic example.

  Y = 1.18463219045513577000
  X = 0.78643729557800883400
Y/X = 1.50632758277882170000 = Tan 0.984735000 as per Cordic algorithm
  Y = 1.19000041997984160000
  X = 0.78999936737183734700
Y/X = 1.50633085180653257000 = Tan 0.984736000 as per Cordic algorithm

The "very simple" example is for the tangent of
0.984735  , but the cordic example is calculated for
0.984736  , ( the 5 becomes a 6 )

I still very much enjoy reading your website, and learning about the wonderful history of the algorithms - thank you so much Jacques.

Kind Regards, Geoff Hitchcox (Christchurch, New Zealand).

Re: Am I a Dummy ????

Dear Geoff,
No your NOT!! wink

Thank you for correcting this old typo.
The angle is 0,984736.
Thank you.

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