word looked up : home / archive

 Borwein's algorithm 

Borwein's algorithm is an algorithm devised by Jonathan[?] and Peter Borwein[?] to calculate the value of 1/π.

It works as follows:

  • Start out by setting

    <math>a_0 = 6 - 4\sqrt{2}</math>

    <math>y_0 = \sqrt{2} - 1</math>

  • Then iterate

    <math>y_{k+1} = \frac{1-(1-y_k^4)^{1/4}}{1+(1-y_k^4)^{1/4}}</math>

    <math>a_{k+1} = a_k(1+y_{k+1})^4 - 2^{2k+3} y_{k+1} (1 + y_{k+1} + y_{k+1}^2)</math>

Then ak converges quartically against 1/π; that is, each iteration approximately quadruples the number of correct digits.

See also


So, nobles, shall you all, Look where the holy legate comes apace, And on our actions set the name of right.html">right PANDULPH. Hail, noble prince of France! Himself to Rome; his spirit is come in, The great metropolis and see of Rome. And tame the savage spirit of wild war.html">war, It may lie gently at the foot of peace.html">peace.html">peace.html">peace LEWIS. Your Grace shall pardon me, I will not back: To be a secondary at control, To any sovereign state throughout the world.html">world. Between this chastis'd kingdom and myself And now 'tis far too huge to be blown out You taught me how to know the face of right, Yea, thrust this enterprise into my heart; His peace with Rome? What is that peace to me? After young Arthur, claim this land for mine; Because that John hath made his peace with Rome? What men provided, what munition sent, That undergo this charge? Who else but I, Sweat in this business and maintain this war? 'Vive le roi!' as I have bank'd their towns? To will this easy match, play'd for a crown? No, no, on my soul, it never shall be said. LEWIS. Outside or inside, I will not return As to my ample hope was promised And cull'd these fiery spirits from the world Even in the jaws of danger and of death. sounds] Let me have audience: I am sent to speak. I come, to learn how you have dealt for him; And warrant limited unto my tongue. And will not temporize with my entreaties; BASTARD. By all the blood that ever fury.

 On wordlookup.net  

All is still licensed under the GNU FDL.
It uses material from the wikipedia.



logo

navig stuff

home
archive