# Is there a lookup function in matlab?

43 views (last 30 days)
John on 6 Jan 2013
Hello,
I am simulating a markov chain using the code below.
transC = [zeros(size(T,1),1), cumsum(T,2)]; %cumulative sum of rows, we will use this to decide on the next step.
n = 10000;
states = zeros(1,n); %storage of states
states(1) = 32; %start at state 1 (or whatever)
for ii = 2:n
%Generate a random number and figure out where it falls in the cumulative sum of that state's trasition matrix row
[~,states(ii)] = histc(rand,transC(states(ii-1),:));
end
It combines a transition probability matrix and a random number to return a sequence of states. e.g 1,2,4,2,5,4,3.....
However, the states are actually letter codes, e.g AA, AC, DC
I have a have a variable called 'convert' where I have a list of the states and their corresponding letter codes. For example
1 AA
2 AC
3 DC
. .
. .
How could I lookup the actual state names and return them in a new variable?
Thank you
##### 0 CommentsShowHide -1 older comments

Sign in to comment.

### Answers (2)

Image Analyst on 6 Jan 2013
Presumably your variable is a cell array where the first column is the state number (kind of unnecessary actually) and the second column is the letter code. So to get the letter code from some variable stateNumber that contains an integer, you'd simply do:
letterCode = convert{stateNumber, 2}; % convert is your cell array variable.
##### 4 CommentsShowHide 3 older comments
Walter Roberson on 7 Jan 2013
This is just array indexing of a cell array.

Sign in to comment.

Walter Roberson on 7 Jan 2013
Also you could look at containers.map
##### 0 CommentsShowHide -1 older comments

Sign in to comment.

### Categories

Find more on Stress and Strain in Help Center and File Exchange

### Tags

No tags entered yet.

### Community Treasure Hunt

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

Start Hunting!