Create a function from a table

Suppose I have a matrix
A = [ 3 0.1; 1 0.2; 2 0.3];
I now want to have a function that takes an entry of the first column and gives the entry in the second column.
In other words, I want to have a matrix B where, for each element in the first column, its second column is the entry of the corresponding second column in A. For example,
B = [ 2 0.3; 2 0.3; 3 0.1; 1 0.2];
Please advise.

 采纳的回答

Try this:
A = [ 1 0.1; 2 0.2; 3 0.3];
A2fcn1 = @(k) A(k,2);
SecondColumn = A2fcn1(2)
SecondColumn =
0.2000
If you want to interpolate instead, use the interp1 (link) function.

更多回答(1 个)

Walter Roberson
Walter Roberson 2018-3-24

1 个投票

Given any finite sets of example values, there are aleph-one (the infinity of cardinal numbers) functions that will exactly calculate the given values to within round-off error. There is no way to automatically choose between these functions as one being "better" than the other -- not unless you specify before-hand which forms of function are to be preferred.

1 个评论

Not that complicated. The question is how to efficiently fill in the second column of B given A and the first column of B.

请先登录,再进行评论。

类别

帮助中心File Exchange 中查找有关 Mathematics 的更多信息

产品

标签

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by