Dynamic variables in loop

Hey there,

I got some string data and want to plot the amount of chips of N amount of players (<15).

I tried dynamic variables (I know they shouldn't really be used) and similar methods but cannot get it to work after quite some time spend on it.

Basically I want to store all the data with sth like 'index_chips.playercount' and 'chips.playercount' instead of computing it manually with 'index_chips1' 'index_chips2' 'index_chips3' and so on.

 for i=1:playercount %N amount of players

index_chips1 = strmatch('1:', text)+4; 
chips1= str2double(text(index_chips1,1));
chips1= num2cell(chips1);
chips1(cellfun(@(chips1) any(isnan(chips1)),chips1)) = [];
chips1=cell2mat(chips1);

plot(chips1)

hold on
end

This term (gives me loads of trouble):

'1:'

also needs to be instead (the colon needs to be after the playercount)

 'playercount:'

Thanks a lot for any suggestions

[jonas]

Can you give some background? What does your data look like? Can you share it? Im sure there is a simple solution that does not involve dynamic variables.

[J S]

Like this repeating more or less with about 40000 lines. The distance between reoccurring strings is variable so the index cannot be simple vector:

    'in'
    'chips'
    ''
    'Seat'
    '2:'
    'Selimeli2'
    ''
    '1500'
    'in'
    'chips'
    ''
    'Seat'
    '3:'
    'SOSSSSS'
    ''
    '1500'
    'in'
    'chips'
    ''
    'Seat'

Answer 1

[jonas]

Here is something I stitched together to plot the chipcounts. Perhaps not the most efficient code, but no need for dynamic variables. I used dynamic field names as suggested by Steven Lord.

%%obtain data from txt using Reglar Expressions

text = fileread('poker.txt');
exp='\w*\s\W\d+ in chips)';
[a,b]=regexp(text,exp);
for i=1:length(a)
    str=text(a(i):b(i)-10);
    data{i}=strsplit(str,' (');   
end

%%find and store names

for i=1:9
    names{i}=data{i}(1)
end
names=[names{:}];
data2 = [data{:}]; 

%%Manipulate data and plot

for i=1:9
    name=names{i}
    [inds]=strcmp(data2,name);
    chipcnt=data2([false inds(1:end-1)]);
    chipcnt=cellfun(@str2num,chipcnt)
    plot(chipcnt)
    myStruct.(names{i}) = chipcnt
end

myStruct =

struct with fields:

         D4ns3n: [1×60 double]
      Selimeli2: [1×53 double]
        SOSSSSS: [1×43 double]
      ShaveBOST: [1×145 double]
    Rossoneri03: [1500 1497 1494 1471]
            art: [1×37 double]
      snipper66: [1×87 double]
     Competency: [1×81 double]
             ID: [1×145 double]

Answer 2

[J S]

%%Import data from text file.
% Script for importing data from text file

%%Initialize variables.
filename = '/Users/juliushannesschonleber/Documents/POK/HH20170417_T1886468393.txt';
delimiter = ',#()[] ''-';

%%Format for each line of text:
%   column1: text (%q)
%  column2: text (%q)
% For more information, see the TEXTSCAN documentation.
formatSpec = '%s';

%%Open the text file.
fileID = fopen(filename,'r','n','UTF-8');
% Skip the BOM (Byte Order Mark).
fseek(fileID, 3, 'bof');

%%Read columns of data according to the format.
% This call is based on the structure of the file used to generate this
% code. If an error occurs for a different file, try regenerating the code
% from the Import Tool.
text = textscan(fileID, formatSpec, 'Delimiter', delimiter, 'EmptyValue' ,NaN, 'ReturnOnError', false);

%%Close the text file.
fclose(fileID);

%%Clear temporary variables
clearvars filename delimiter formatSpec fileID dataArray ans;
text= text{1,1};
% Index_t = strmatch('Tournament', text);
% Index_h = strmatch('Hand', text);

ind_playercount = strmatch('max', text)-1;
playercount= str2double(text(ind_playercount,1));
playercount= playercount(1,1);

for i=1:playercount

index_chips.playercount = strmatch('1:', text)+4; 
chips1= str2double(text(index_chips1,1));
chips1= num2cell(chips1);
chips1(cellfun(@(chips1) any(isnan(chips1)),chips1)) = [];
chips1=cell2mat(chips1);

plot(chips1)

hold on
end

Answer 3

[Steven Lord]

Don't create variables named like that.

numPlayers = 10;
chipCounts = randi([1 100], 1, numPlayers)

Now when you want the chip count for player 7 (for example) it's easy.

chipCounts(7)

Plotting chip counts? Also easy.

figure

subplot(3, 1, 1)
plot(chipCounts)
title('Line plot');

subplot(3, 1, 2);
bar(chipCounts)
title('Bar chart');

subplot(3, 1, 3)
pie(chipCounts)
title('Anyone for pie?');

[J S]

Thanks but thats not what I need. The chips for each player vary from play to play and I want to create a cell array for each player with the amount of chips they have at the end of each hand played

[Steven Lord]

Don't create one variable per player. I would create a struct with one field per player and store vectors in those fields (you can use dynamic field names to refer to the field if you have a char vector containing the name of the field) or a table array with one table variable per player.

Creating variables with dynamic names can be slow and can lead to Bobby Tables syndrome or "poofing".