# Finding a variable in a large table

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George am 8 Dez. 2022
Kommentiert: Voss am 9 Dez. 2022
I'm quite a novice to MATLAB so apologies for any language I may use which may be confusing
I have a 2570x16 sized table, which relates to data about every UK train station, i.e. usage statistics, I have written a menu function which allows the selected station to become a string, what do I need to do so that the Station can be found in the name column, and then this can be used to recall the other 15 parts of data about the station?
Many thanks
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### Akzeptierte Antwort

Voss am 8 Dez. 2022
% a table with station names and other info:
t = table(["Picadilly Circus"; "St. John's Wood"; "Cockfosters"],rand(3,1),rand(3,1), ...
'VariableNames',{'name' 'other info 1' 'other info 2'})
t = 3×3 table
name other info 1 other info 2 __________________ ____________ ____________ "Picadilly Circus" 0.14357 0.81944 "St. John's Wood" 0.2586 0.93962 "Cockfosters" 0.47828 0.34349
% the station you want to know about:
station = "Cockfosters";
% get all the info about that station:
result = t(strcmp(t.name,station),:) % result is a table with one row
result = 1×3 table
name other info 1 other info 2 _____________ ____________ ____________ "Cockfosters" 0.47828 0.34349
% and/or get just the "other info" for that station:
% (this assumes 'name' is the first column of the table)
result = t{strcmp(t.name,station),2:end} % result is a numeric array in this case
result = 1×2
0.4783 0.3435
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Voss am 9 Dez. 2022
You're welcome!

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### Weitere Antworten (2)

Jon am 8 Dez. 2022
Bearbeitet: Jon am 8 Dez. 2022
Here's a simple example, which I think you could extend to your situation
% make an example table
name = {'fish','cat','dog','cat','mouse','mouse','fish','cat'}'
weight = [0.8, 1.3, 2.2, 1.1, 0.2, 0.3, 0.9, 1.4]'
bodyLength = [102,503,608, 429,15,18, 154,496]'
T = table(name,weight,bodyLength)
% get the weights and lengths of all of the cats
idl = strcmp('cat',T.name);
Tcat = T(idl,:) % a table with just cat data
% or if you just want the weight of the fish
idl = strcmp('fish',T.name);
wFish = T.weight(idl)
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Bora Eryilmaz am 8 Dez. 2022
Bearbeitet: Bora Eryilmaz am 8 Dez. 2022
% Create a table
T = table;
T.Name = ["London"; "Paris"];
T.Data1 = {15; 20};
T.Data2 = {-1; 2};
T
T = 2×3 table
Name Data1 Data2 ________ ______ ______ "London" {[15]} {[-1]} "Paris" {[20]} {[ 2]}
% Find index of Name
I = strcmp(T.Name, 'Paris');
% Find data for that Name
T{I,:}
ans = 1×3 string array
"Paris" "20" "2"
% or, extract data as its own 1-row table
T(I,:)
ans = 1×3 table
Name Data1 Data2 _______ ______ _____ "Paris" {[20]} {[2]}
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