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

[Jan]

The question would be more clear, if you provide YourTable in valid Matlab syntax.

[Reddy]

look up table for above question

(All bold characters are in 1st column, all italics characters are in 2nd column and normal font are in 3rd column)

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

the above table resembles to basic trigonometric sine and cosine values for standard values.

[Jan]

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]

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

Answer 1

[TAB]

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