Results 1 to 3 of 3

Math Help - Interpolating z(x,y) data point from 4 data points (rectangular)?

  1. #1
    Newbie
    Joined
    May 2011
    Posts
    4

    Question Interpolating z(x,y) data point from 4 data points (rectangular)?

    Hello

    I am trying to determine the general formula that will allow me to interpolate a value "z" related to any point (x,y) where x1<x<x2 and y1<y<y2 from a surface map defined by 4 points z1(x1,y1),z2(x1,y2),z3(x2,y1) and z4(x2,y2).

    I can do it in Excel for discrete values, and have tried using a kind of "weighted average" approach but I can't seem to nail this general formula.

    Any help appreciated.

    Refer to this Excel file for reference.

    Thanks

    SKB
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Grand Panjandrum
    Joined
    Nov 2005
    From
    someplace
    Posts
    14,972
    Thanks
    4

    Re: Interpolating z(x,y) data point from 4 data points (rectangular)?

    Quote Originally Posted by ShouldKnowBetter View Post
    Hello

    I am trying to determine the general formula that will allow me to interpolate a value "z" related to any point (x,y) where x1<x<x2 and y1<y<y2 from a surface map defined by 4 points z1(x1,y1),z2(x1,y2),z3(x2,y1) and z4(x2,y2).

    I can do it in Excel for discrete values, and have tried using a kind of "weighted average" approach but I can't seem to nail this general formula.

    Any help appreciated.

    Refer to this Excel file for reference.

    Thanks

    SKB
    You will find this in Abramowitz and Stegun which is available on-line.

    CB
    Last edited by CaptainBlack; June 20th 2011 at 07:16 PM. Reason: Spelling of Irene Stegun's name
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Newbie
    Joined
    May 2011
    Posts
    4

    Thumbs up Re: Interpolating z(x,y) data point from 4 data points (rectangular)?

    Quote Originally Posted by CaptainBlack View Post
    You will find this in Abramowitz and Stegen which is available on-line.

    CB
    Thanks found it.
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Replies: 0
    Last Post: May 9th 2011, 12:27 PM
  2. Equation from known data points
    Posted in the Geometry Forum
    Replies: 1
    Last Post: September 12th 2010, 10:56 PM
  3. Replies: 2
    Last Post: July 6th 2010, 06:33 PM
  4. extracting data from matlab data structures
    Posted in the Math Software Forum
    Replies: 4
    Last Post: May 19th 2010, 04:12 PM
  5. 3D surface from data points in matlab
    Posted in the Math Software Forum
    Replies: 3
    Last Post: December 25th 2009, 07:43 AM

/mathhelpforum @mathhelpforum