How do I find the indices of the value of my matrix?

How can I find the indices and exactly position of the value of the attached file. For example find index of value = -69.19 from the attached file.

Thanks

Answer 1

[Stephen23]

The answer depends entirely on how you define "equals" for floating point numbers:

>> [R,C] = find(abs(XX - -69.19)<1e-4)
R = []
C = []
>> [R,C] = find(abs(XX - -69.19)<1e-3)
R =  25
C =  124
>> [R,C] = find(abs(XX - -69.19)<1e-2)
R =
    3
    6
   10
   14
   17
   18
   21
   25
   29
   32
C =
   108
   110
   113
   116
   118
   119
   121
   124
   127
   129

Answer 2

[KALYAN ACHARJYA]

Load the mat file, say as data variable

idx=find(data==-69.19)

Please read about floating number precision (Must)

https://www.mathworks.com/help/matlab/matlab_prog/floating-point-numbers.html

Example:

>> A=[1 -69.19 3.5 10];
>> idx=find(A==-69.19)
idx =
     2

[Stephen23]

This is not robust and does not work for the provided value:

>> any(XX(:) == -69.19)
ans = 0

Answer 3

[Farshid Daryabor]

the commend tried before does not work,

idx=find(XX == -69.19);

idx = []

Answer 4

[Farshid Daryabor]

I actually looking for an individual index (idx) for the corresponding value, as same for the latitude (idy). by the finding the indices I want to find a data as arranged based on the lon and lat,

data = var(idx,idy);

Answer 5

[Farshid Daryabor]

Dear Stephen,

the second one is exactly what I am looking for. It's possible explaine why abs(XX - (-69.19)) should less than (1e-n), and how is defined 'n'

[R,C] = find(abs(XX - -69.19)<1e-3)

R = 25

C = 124

Answer 6

[Farshid Daryabor]

the problem is when I want to find the certain variable from the matrix arranged based on the longitude and latitude, how can I find it by having the corresponding indices

Data=Data(y,x)

[Farshid Daryabor]

solved problem