how to store value in variables of one column in cell array from another column in cell array?

Question

Aakriti Srivastava 2022-6-29

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此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1750790-how-to-store-value-in-variables-of-one-column-in-cell-array-from-another-column-in-cell-array

评论： Aakriti Srivastava 2022-7-25

采纳的回答： Voss

The problem is something like this:

V_table =

8×4 table

Variable lb initial_val ub

_____________ ____ ___________ ____

{'Lser_B7Tx'} 0 0.4 2

{'Lser_B7Rx'} 0 0.4 2

{'QCsmd' } 30 70 80

{'QLemb' } 30 60 80

{'Lshu_B7' } 0 4 10

{'fQ' } 2000 2500 3000

{'Cshu_B7' } 0 0.01 2

{'QLsmd' } 30 60 80

This is code I am using for what I try to achieve i.e. to store the values such as 0.4,0.4,....(initial_value) to variables Lser_B7Tx', 'Lser_B7Rx'......'QLsmd'.

for i = 1:length((V_table.Variable)

V_table.Variable{i} = V_table.initial_val{i}

V_table.Variable

end

But I am getting the error : Error using nport_B7DPX (line 125)

Brace indexing is not supported for variables of this type.

Would anyone please let me know how can I assign value to the variables of cell array

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Pooja Kumari 2022-6-29

Can you share the table file.

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Answer 1

Voss 2022-6-29

1
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1750790-how-to-store-value-in-variables-of-one-column-in-cell-array-from-another-column-in-cell-array#answer_996795

在 MATLAB Online 中打开

% your V_table:
V_table = table( ...
    {'Lser_B7Tx';'Lser_B7Rx';'QCsmd';'QLemb';'Lshu_B7';'fQ';'Cshu_B7';'QLsmd'}, ...
    [0;0;30;30;0;2000;0;30], ...
    [0.4;0.4;70;60;4;2500;0.01;60], ...
    [2;2;80;80;10;3000;2;80], ...
    'VariableNames',{'Variable','lb','initial_val','ub'})
V_table = 8×4 table
      Variable        lb     initial_val     ub 
    _____________    ____    ___________    ____

    {'Lser_B7Tx'}       0        0.4           2
    {'Lser_B7Rx'}       0        0.4           2
    {'QCsmd'    }      30         70          80
    {'QLemb'    }      30         60          80
    {'Lshu_B7'  }       0          4          10
    {'fQ'       }    2000       2500        3000
    {'Cshu_B7'  }       0       0.01           2
    {'QLsmd'    }      30         60          80

Instead of making a bunch of different variables in your workspace that contain all the same information of what's already in the table, you can redefine your table slightly, so that the Variable column is the RowNames of the table:

V_table.Properties.RowNames = V_table.Variable;
V_table.Variable = []
V_table = 8×3 table
                  lb     initial_val     ub 
                 ____    ___________    ____

    Lser_B7Tx       0        0.4           2
    Lser_B7Rx       0        0.4           2
    QCsmd          30         70          80
    QLemb          30         60          80
    Lshu_B7         0          4          10
    fQ           2000       2500        3000
    Cshu_B7         0       0.01           2
    QLsmd          30         60          80

Then you can get easily whatever you need, by indexing with a row name and a column name:

V_table{'fQ','lb'}
ans = 2000
V_table{'QLsmd','initial_val'}
ans = 60
V_table{'QCsmd','ub'}
ans = 80

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Voss 2022-6-30

在 MATLAB Online 中打开

I think, regardless of how you need to use the variables, you can keep their values in the table, either as you had it originally or with the variable names as the row names.

For example, call a function using initial_val of fQ and QCsmd as inputs (using the variables as RowNames as my answer had):

my_function(V_table{'fQ','initial_val'},V_table{'QCsmd','initial_val'})

That's the same as if you made separate variables for those two things and then passed them to the function.

On the other hand, it may be convenient to bundle all the variables together in a structure. Here, starting from your original table, I'll make a structure of the variables' initial_val values:

% your original V_table:
V_table = table( ...
    {'Lser_B7Tx';'Lser_B7Rx';'QCsmd';'QLemb';'Lshu_B7';'fQ';'Cshu_B7';'QLsmd'}, ...
    [0;0;30;30;0;2000;0;30], ...
    [0.4;0.4;70;60;4;2500;0.01;60], ...
    [2;2;80;80;10;3000;2;80], ...
    'VariableNames',{'Variable','lb','initial_val','ub'});
args = [V_table.Variable num2cell(V_table.initial_val)].';
S = struct(args{:})
S = struct with fields:
    Lser_B7Tx: 0.4000
    Lser_B7Rx: 0.4000
        QCsmd: 70
        QLemb: 60
      Lshu_B7: 4
           fQ: 2500
      Cshu_B7: 0.0100
        QLsmd: 60

Then you can pass that structure to your functions (which, you could've passed the original table too), or you can pass just individual fields:

my_function(S.fQ,S.QCsmd)

(And obviously you could make similar structures for the lb and ub of the variables as well.)

And regardless of what the functions do to change the variables, you can re-assign the new value back where it belongs (in a structure or table) by returning the individual variable (or structure or table) back from the function and then doing the assignment.

Ultimately, it's unlikely that keeping 8 (or 24, with the lb and ub values) separate scalar variables is best, given that they're already organized in the table to begin with.

If it's unclear how to proceed, please share some code of the functions that need to operate with these variables.

Aakriti Srivastava 2022-6-30

编辑：Aakriti Srivastava 2022-6-30

在 MATLAB Online 中打开

Hey Voss, thankyou and truly appreciate your help :). this is quite similar to what I want to do but unfortuantely I am getting some brace indexing error to make you undertand my problem clearly I am attaching my code snippet for the stage ahead.

Step1: Reading text file to create varibale tables with its corresponding values.That you have seen above like this

V_table =

8×4 table

Variable lb initial_val ub

_____________ ____ ___________ ____

{'Lser_B7Tx'} 0 0.4 2

{'Lser_B7Rx'} 0 0.4 2

{'QCsmd' } 30 70 80

{'QLemb' } 30 60 80

{'Lshu_B7' } 0 4 10

{'fQ' } 2000 2500 3000

{'Cshu_B7' } 0 0.01 2

{'QLsmd' } 30 60 80

Step2: Sort the variables with name L from the other section of text file

strt_ckt_idx = strfind(data,'INDQ');

end_ckt_idx = strfind(data,'DEF0P');

% node_array(1,1) = str2double(data(strt_ckt_idx(1)+5));

% node_array(1,2) = str2double(data(strt_ckt_idx(1)+7));

element_name_INDQ = extractBetween(data(strt_ckt_idx+5:end_ckt_idx),['L','=','{',' '],[' ','}',' ','Q={ QL'])

node_INDQ = extractBetween(data(strt_ckt_idx:end_ckt_idx),['INDQ',' '],[' ','ID="L']);

total_INDQ = length(strt_ckt_idx);

and created the table which looks something like this:

T =

3×3 table

element_name_INDQ node1_INDQ node2_INDQ

_________________ __________ __________

{'Lser_B7Tx'} 6 4

{'Lser_B7Rx'} 5 4

{'Lshu_B7' } 4 0

step 3: Now what I am trying to do is to store the value corresponding to this variable from the above V_table usimg the code shpwn below but I am getting the error .

for i = 1:total_INDQ

for j = 1:length(V_table.Variable)

if strcmp(V_table.Variable{j},element_name_INDQ{i})

args = [element_name_INDQ{i},V_table.initial_val{j}].'

% S_INDQ = struct(args{:})

end

Error using tabular/numArgumentsFromSubscript (line 111)

Brace indexing is not supported for variables of this type.

args = [element_name_INDQ{i},V_table.initial_val{j}].'

The step4 will be to perform mathematical and logical operation on the variable. Hope now I am clear with the question. But I really appreciate all your help. Thankyou. I need solution for this

y_cap = cellfun(@(x) w'*x, element_name_INDQ{i}, 'un', 0)

Voss 2022-6-30

在 MATLAB Online 中打开

V_table = table( ...
    {'Lser_B7Tx';'Lser_B7Rx';'QCsmd';'QLemb';'Lshu_B7';'fQ';'Cshu_B7';'QLsmd'}, ...
    [0;0;30;30;0;2000;0;30], ...
    [0.4;0.4;70;60;4;2500;0.01;60], ...
    [2;2;80;80;10;3000;2;80], ...
    'VariableNames',{'Variable','lb','initial_val','ub'})
V_table = 8×4 table
      Variable        lb     initial_val     ub 
    _____________    ____    ___________    ____

    {'Lser_B7Tx'}       0        0.4           2
    {'Lser_B7Rx'}       0        0.4           2
    {'QCsmd'    }      30         70          80
    {'QLemb'    }      30         60          80
    {'Lshu_B7'  }       0          4          10
    {'fQ'       }    2000       2500        3000
    {'Cshu_B7'  }       0       0.01           2
    {'QLsmd'    }      30         60          80
% in your code, "T" comes from "data", but
% I don't have "data", so I hard-code T:
T = table( ...
    {'Lser_B7Tx';'Lser_B7Rx';'Lshu_B7'}, ...
    [6;5;4], ...
    [4;4;0], ...
    'VariableNames',{'element_name_INDQ' 'node1_INDQ' 'node2_INDQ'})
T = 3×3 table
    element_name_INDQ    node1_INDQ    node2_INDQ
    _________________    __________    __________

      {'Lser_B7Tx'}          6             4     
      {'Lser_B7Rx'}          5             4     
      {'Lshu_B7'  }          4             0     
% use ismember to get the index of each T.element_name_INDQ
% in V_table.Variable:
[~,idx] = ismember(T.element_name_INDQ,V_table.Variable)
idx = 3×1
     1
     2
     5
% then build a structure of only those initial_val's:
args = [T.element_name_INDQ,num2cell(V_table{idx,'initial_val'})].';
S_INDQ = struct(args{:})
S_INDQ = struct with fields:
    Lser_B7Tx: 0.4000
    Lser_B7Rx: 0.4000
      Lshu_B7: 4

Voss 2022-6-30

编辑：Voss 2022-6-30

在 MATLAB Online 中打开

(Setting up table and structure variables:)

V_table = table( ...
    {'Lser_B7Tx';'Lser_B7Rx';'QCsmd';'QLemb';'Lshu_B7';'fQ';'Cshu_B7';'QLsmd'}, ...
    [0;0;30;30;0;2000;0;30], ...
    [0.4;0.4;70;60;4;2500;0.01;60], ...
    [2;2;80;80;10;3000;2;80], ...
    'VariableNames',{'Variable','lb','initial_val','ub'});
T = table( ...
    {'Lser_B7Tx';'Lser_B7Rx';'Lshu_B7'}, ...
    [6;5;4], ...
    [4;4;0], ...
    'VariableNames',{'element_name_INDQ' 'node1_INDQ' 'node2_INDQ'});
[~,idx] = ismember(T.element_name_INDQ,V_table.Variable);
args = [T.element_name_INDQ,num2cell(V_table{idx,'initial_val'})].';
S_INDQ = struct(args{:});

You can use fieldnames to get the fields of a structure:

fields = fieldnames(S_INDQ)
fields = 3×1 cell array
    {'Lser_B7Tx'}
    {'Lser_B7Rx'}
    {'Lshu_B7'  }

and then loop over them:

for ii = 1:numel(fields)
    fprintf('field: %s',fields{ii})
    fprintf('value: %f',S_INDQ.(fields{ii}))
    % do whatever with S_INDQ.(fields{ii})
end
field: Lser_B7Tx
value: 0.400000
field: Lser_B7Rx
value: 0.400000
field: Lshu_B7
value: 4.000000

Or, in this case, loop over the values of T.element_name_INDQ (notice: not using structure S_INDQ here; using the tables T and V_table only):

for ii = 1:height(T)
    var_name = T.element_name_INDQ{ii}
    var_value = V_table{strcmp(V_table.Variable,var_name),'initial_val'}
end
var_name = 'Lser_B7Tx'
var_value = 0.4000
var_name = 'Lser_B7Rx'
var_value = 0.4000
var_name = 'Lshu_B7'
var_value = 4

And in that last case, it's convenient for V_table to have its RowNames be the names of the variables (going back to the idea in my original answer):

V_table.Properties.RowNames = V_table.Variable;
V_table.Variable = []
V_table = 8×3 table
                  lb     initial_val     ub 
                 ____    ___________    ____

    Lser_B7Tx       0        0.4           2
    Lser_B7Rx       0        0.4           2
    QCsmd          30         70          80
    QLemb          30         60          80
    Lshu_B7         0          4          10
    fQ           2000       2500        3000
    Cshu_B7         0       0.01           2
    QLsmd          30         60          80

because the syntax is cleaner:

for ii = 1:height(T)
    var_name = T.element_name_INDQ{ii}
    var_value = V_table{var_name,'initial_val'}
end
var_name = 'Lser_B7Tx'
var_value = 0.4000
var_name = 'Lser_B7Rx'
var_value = 0.4000
var_name = 'Lshu_B7'
var_value = 4

Aakriti Srivastava 2022-7-25

Hy Voss, I have one issue with regexp if you have any information regarding this would you please help me out so the question is.

I want to read using regexp from port 12 to port 22 as

PORT 23 P=1 Z=50

PORT 12 P=2 Z=50 PIN_ID=CB7TX

PORT 13 P=3 Z=50 PIN_ID=CB7RX

PORT 14 P=4 Z=50 PIN_ID=CB66TX

PORT 15 P=5 Z=50 PIN_ID=CB25TX

PORT 16 P=6 Z=50 PIN_ID=CB25RX

PORT 22 P=7 Z=50 PIN_ID=CB66RX

This is the code I am using

[port_tokens2,port_match3] = regexp(data,'PORT\s+(\d+)\s+(\w+=\d)+\s+\w+=\d+\s','tokens','match')

Result I got

port_match3 =

1×7 cell array

Columns 1 through 5

{'PORT 23 P=1 Z=5…'} {'PORT 12 P=2 Z=50 '} {'PORT 13 P=3 Z=50 '} {'PORT 14 P=4 Z=50 '} {'PORT 15 P=5 Z=50 '}

Columns 6 through 7

{'PORT 16 P=6 Z=50 '} {'PORT 22 P=7 Z=50 '}

But I want to read PIN_ID = CBXXXX also so I used this expression

[port_tokens2,port_match3] = regexp(data,'PORT\s+(\d+)\s+(\w+=\d)+\s+\w+=\d+\s\w+=w+','tokens','match')

This is the result I got

port_match3 =

0×0 empty cell array

Would you please let me know what is wrong with my expression that I am not able to read the whole sentence.

Voss 2022-7-25

在 MATLAB Online 中打开

There's a backslash missing before the last w you added. I included that backslash, and I removed the tokens because it doesn't seem like you need them. Does this do what you want now?

data = { ...

'PORT 23 P=1 Z=50'

'PORT 12 P=2 Z=50 PIN_ID=CB7TX'

'PORT 13 P=3 Z=50 PIN_ID=CB7RX'

'PORT 14 P=4 Z=50 PIN_ID=CB66TX'

'PORT 15 P=5 Z=50 PIN_ID=CB25TX'

'PORT 16 P=6 Z=50 PIN_ID=CB25RX'

'PORT 22 P=7 Z=50 PIN_ID=CB66RX'

};

port_match3 = regexp(data, ...

'PORT\s+\d+\s+\w+=\d+\s+\w+=\d+\s\w+=\w+','match')

port_match3 = 7×1 cell array

{0×0 cell} {1×1 cell} {1×1 cell} {1×1 cell} {1×1 cell} {1×1 cell} {1×1 cell}

port_match3{:}

ans = 0×0 empty cell array

ans = 1×1 cell array

{'PORT 12 P=2 Z=50 PIN_ID=CB7TX'}

ans = 1×1 cell array

{'PORT 13 P=3 Z=50 PIN_ID=CB7RX'}

ans = 1×1 cell array

{'PORT 14 P=4 Z=50 PIN_ID=CB66TX'}

ans = 1×1 cell array

{'PORT 15 P=5 Z=50 PIN_ID=CB25TX'}

ans = 1×1 cell array

{'PORT 16 P=6 Z=50 PIN_ID=CB25RX'}

ans = 1×1 cell array

{'PORT 22 P=7 Z=50 PIN_ID=CB66RX'}

Aakriti Srivastava 2022-7-25

Yes it does thankyou so much :) Great help.

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how to store value in variables of one column in cell array from another column in cell array?

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