increasing precison using fprintf for text file

Question

sermet 2015-4-23

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/213244-increasing-precison-using-fprintf-for-text-file

编辑： per isakson 2015-4-23

cellArray =

    [ 334]    [38.141794059793398]    [31.983184186130529]    [1.751451095529832e+03]
    [ 352]    [38.094455446389709]    [31.940682658186898]    [1.779530219110660e+03]
    [ 404]    [38.162956465159276]    [32.019563510560964]    [1.542875077314675e+03]
    [ 414]    [38.176654734516106]    [32.068817577008474]    [1.389497182917781e+03]
    [ 476]    [38.075635175382899]    [32.027977260576755]    [1.994276513063349e+03]
    [2729]    [38.229399882994215]    [31.934421897750756]    [1.167495300253853e+03]
    [2730]    [38.205404821919039]    [31.911611428797361]    [1.291408437962644e+03]
    [2742]    [38.104502101643973]    [31.931891003528762]    [1.774978352412581e+03]
 Name           Size            Bytes  Class     Attributes
 cellArray      8x4              3840  cell      global

% I use below codes to write cellArray into txt file

startingFolder='C:\Program Files\MATLAB';
 if ~exist(startingFolder, 'dir');
    startingFolder = pwd;
 end
 defaultFileName=fullfile(startingFolder, '*.txt');
 [baseFileName, folder]=uiputfile(defaultFileName, 'Select a file');
  if baseFileName == 0
    return
  end
  fullFileName = fullfile(folder, baseFileName);  
  c=cellfun(@num2str,cellArray,'un',0);
   [n,m]=size(c);
form=[repmat('%s   ',1,m) ' \r\n'];
fid = fopen(fullFileName, 'w');
for k=1:n
  fprintf(fid, form, c{k,:});
end
fclose(fid);

% but data (2-3-4rd columns) are written only 4 numbers after the comma (like, 38.1418). I need to write the data into txt file without rounding.

3 个评论
显示 1更早的评论隐藏 1更早的评论

sermet 2015-4-23

I see but how can I apply this for cellfun?

per isakson 2015-4-23

编辑：per isakson 2015-4-23

在 MATLAB Online 中打开

Replace

@num2str

by

@(str) num2str( str, format_specifier )

or better

    >> cellfun( @num2str, {123,34567/3}, {'%d','%18.12f'}, 'uni', false )
    ans = 
        '123'    '11522.333333333334'

请先登录，再进行评论。

请先登录，再回答此问题。

Answer 1

Star Strider 2015-4-23

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/213244-increasing-precison-using-fprintf-for-text-file#answer_176457

If you need full precision on all numeric variables and want to use repmat to create your ‘form’ format descriptors, instead of %s, I would use %23.15E. That will print all of them out to full precision.

7 个评论
显示 5更早的评论隐藏 5更早的评论

Star Strider 2015-4-23

在 MATLAB Online 中打开

No worries.

The only change I suggested is to use this assignment for ‘form’:

form = '%5d %23.15E %23.15E %23.15E\n';

Experiment with it to see if it works to your satisfaction.

sermet 2015-4-23

在 MATLAB Online 中打开

try7.txt

c=cellfun(@num2str,cellArray,'un',0);
     [n,m]=size(c);
  form = '%5d  %23.15E  %23.15E  %23.15E\n'
    fid = fopen(fullFileName, 'w');
  for k=1:n
    fprintf(fid, form, c{k,:});
  end
  fclose(fid);