Creating a txt file with different types of data stored in each column?

I am trying to create a .txt file with the following data in this format.

e 5.4 300+2i

f 3.3 3+200i

c 2.2 9.9+210i

f 1.1 2.290+0.1i

with e,f,c,f beign strings, and the last numbers being complex numbers.

I'm not sure what the best way to go about this. Should I create a cell array and then use fprintf to create a .txt file?

Answer 1

[Star Strider]

If you have R2013b or later, create the cell array, then use the cell2table function to create a table, then use writetable to write the file.

Example —

C = {'e' 5.4+300+2i
     'f' 3.3+3+200i
     'c' 2.2+9.9+210i
     'f' 1.1+2.290+0.1i};

T = cell2table(C)

T =

    4×2 table

      C1         C2    
      ___    __________

      'e'    305.4+2i  
      'f'      6.3+200i
      'c'     12.1+210i
      'f'     3.39+0.1i

Then write to the file.

[JM]

Hey Star Strider, thank you for the answer. I've followed your steps and successfully created the file, however, I am now having problems with the next thing I am required to do.

I have to use textscan to read from the file. However, when I read from textscan it is creating cells that are not in the proper format.

Currently I have

fileid = fopen('CharNumber.txt', 'r')

C = textscan(fileid,'')

fclose(fileid)

I've tried a variety of formatSpecs, but I cannot seem to reproduce it in the format I need.

I am looking for a 4x3 array with the first column having the letter, the second column having a number, and the third column having the complex number.

Example e 5.4 300+2i

[Star Strider]

My pleasure.

I don’t know what ‘variety of format specs’ you’ve tried.

For a file format such as:

e 5.4 300+2i

I would use '%s%f%f'. This reads the first field as a string and the second two as floating point variables, the first real and the second complex. Each will be read into a different cell array. If necessary, experiment with the various name-value pairs to get the result you want.

[JM]

Hey Star Strider.

I've actually tried that format spec, but for some reason I am getting C = 1x3 cell array. The first cell has a 5x1 array with all of the values in it, the other two have NaN and NaN.

Here is my code:

%Q1

C = {'e' 5.4 300+2i

       'f' 3.3 3+200i

       'c' 2.2 9.9+210i

       'f' 1.1 2.290+0.1i};

CharNumber = cell2table(C)

writetable(CharNumber)
%Q2

fileid = fopen('CharNumber.txt', 'r')

C = textscan(fileid,'%s%f%f')

celldisp(C)

fclose(fileid)

-----

And here is what I'm getting (attached as file)

[Walter Roberson]

 reconstructed = [C(1), num2cell(C{2}), num2cell(C{3})];

[Star Strider]

I did not realise this is a homework assignment. My objective was to use writetable so you can use readtable to read it again. The writetable function defaults to a comma-delimited text file, so in your textscan call, specify the delimiter to be a comma. That should work.