How to retrieve a matched element or a number in lookup table

Question

Reddy 2012-7-9

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/43081-how-to-retrieve-a-matched-element-or-a-number-in-lookup-table

sir,

deg sine_value cosine_value; 0 0 1; 30 0.5 0.866; 45 0.707 0.707; 60 0.866 0.5 ; 90 1 0;

with reference to above lookup table,

if i enter 2nd column element and 3rd column element for search, it is working fine and we are getting in which row they are present.

suppose the search is made for element present in 2nd colum and an element present in 3rd column then, by using the following formula

[mindiff, row] = min( (YourTable(:,2) - V1).^2 + (YourTable(:,3) - V2).^2 );

we can able to find in which row they are present. But, task is we need to retrieve the element which is present in 1st column present in the matched row(i.e., row x 1 element should be retrieved and stored in a variable).

for example: from the above formula, if we enter V1=0.5, and V2=0.866.. then, we can able to find row=2. but the task is we have to retrieve the element present in 1st column and the matching row(i.e., we have to retrieve 30 for this example). please help me for this problem.

thanks reddy

4 个评论
显示 2更早的评论隐藏 2更早的评论

Jan 2012-7-9

编辑：Jan 2012-7-9

在 MATLAB Online 中打开

It is not clear how "deg" and "o" are stoired in the same array. Is it a cell srtring and both are strings? An example for valid Matlab syntax:

YourTable = [0, 0, 0; 30, 05, 0.866; etc]

or

YourTable = {'deg', 'sine_value', 'cosine_value'; ...
             0, 0, 0; 30, 05, 0.866; etc}

or whatever meest the array you use. The less we have to guess, the more efficient is the creation of a helpful answer.

Reddy 2012-7-9

the first one is correct. i.e., YourTable = [0, 0, 0; 30, 05, 0.866; etc] is the correct choice of lookup table... please help me to find the answer which i have described earlier today for this lookup table.. thanks, sridhar

请先登录，再进行评论。

请先登录，再回答此问题。

Answer 1

TAB 2012-7-9

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/43081-how-to-retrieve-a-matched-element-or-a-number-in-lookup-table#answer_52990

编辑：TAB 2012-7-9

在 MATLAB Online 中打开

TrigTable = [      0         0    1.0000
             30.0000    0.5000    0.8660
             45.0000    0.7070    0.7070
             60.0000    0.8660    0.5000
             90.0000    1.0000         0];
V1=0.5;
V2=0.866;
SineIdx   = find(TrigTable(:,2)==V1);
CosineIdx = find(TrigTable(:,3)==V2);
if SineIdx==CosineIdx
 AngleDeg = TrigTable(SineIdx,1);
end