Convert Cell Array into equation

Question

ga97cad 2021-10-21

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此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1568863-convert-cell-array-into-equation

评论： Stephen23 2021-10-21

matlab_example.csv

Hi everyone!

I have a simple question and I have already been looking for an answer that suits my problem here in the community but haven't found anything yet so here I go:

I am reading a .csv file with the function readtable and it works perfectly fine, but there is one column were an quation like this is written: 19*32 for example in each cell. What i want is Matlab to just calculate that equation for each cell of the array, to just get one number. For example for the equation above it would be 608. Matlab reads this column as a Cell Array and I already tried the cell2mat function, but that didn't help me unfortunetly....

I have attached a file with an exmaple of the column that I want to solve.

Thank you for your help and best regards from germany

Lukas

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Stephen23 2021-10-21

在 MATLAB Online 中打开

matlab_example.csv

Slightly more robust would be to use STR2NUM:

T = readtable('matlab_example.csv','Delimiter',',');
V = cellfun(@str2num, T.flaeche_li_2)
V = 28×1
   540
   360
   324
   720
   432
   414
   810
   468
   540
   450

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Answer 1

Voss 2021-10-21

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此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1568863-convert-cell-array-into-equation#answer_813543

在 MATLAB Online 中打开

If C is a cell array containing a MATLAB expression in each cell, then the following code will evaluate the expressions and return a vector of results:

V = cellfun(@(x)eval(x),C);

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ga97cad 2021-10-21

Thank you, Benjamin!! your solution helped me to solve my problem and I marked it as accepted!! best regards, Lukas

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Answer 2

Dave B 2021-10-21

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链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1568863-convert-cell-array-into-equation#answer_813548

在 MATLAB Online 中打开

matlab_example.csv

I think you could use a combination of cellfun (to run on each cell) and eval (to evaluate the expression):

a=readtable('matlab_example.csv','Delimiter',',');
a.evaluated=cellfun(@eval,a.flaeche_li_2);
head(a)
ans = 8×2 table
    flaeche_li_2    evaluated
    ____________    _________

     {'30*18'}         540   
     {'20*18'}         360   
     {'18*18'}         324   
     {'40*18'}         720   
     {'24*18'}         432   
     {'23*18'}         414   
     {'45*18'}         810   
     {'26*18'}         468   