How do I read a file in using fopen correctly

Question

Daniel Montgomery 2020-2-9

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/504541-how-do-i-read-a-file-in-using-fopen-correctly

评论： Walter Roberson 2020-2-10

I am trying to read in spectroscopic data in using fopen and place the data into the y array. The file dimensions are 69 * 22533. What am I doing incorrectly?

x = 1:5; %5
y = zeros(69,22533);
fileID = fopen('Pandora166s1_LabGSFC_20200115_L0_subset (1).txt','w');
fprintf(fileID,'%d %4.4f\n',y);
fclose(fileID);

3 个评论
显示 1更早的评论隐藏 1更早的评论

Daniel Montgomery 2020-2-10

It is an index less text file. My first character is a string I want to import the data from matlab. The data in Y would start at zero and start a new row at the 69th character.

Walter Roberson 2020-2-10

Please show an extract of the file.

请先登录，再进行评论。

请先登录，再回答此问题。

Answer 1

Daniel Montgomery 2020-2-10

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/504541-how-do-i-read-a-file-in-using-fopen-correctly#answer_414691

I did not know a consistent number of characters was required for reading in a file. What would be the best way to to import this to get cell seperated values? I am trying to isolate a range of cloumns for data analaysis.

2 个评论
显示无隐藏无

Walter Roberson 2020-2-10

Consistency of line length is not usually required, but when we asked about the format you said "The data in Y would start at zero and start a new row at the 69th character". That would not make sense unless you had a fixed width line.

Walter Roberson 2020-2-10

What you attached has three columns per line, such as "Instrument", "type:" and "Pandora". But that looks pretty accidental to me and it looks more likely that you have a parameter name phrase followed by : then a parameter value that is not necessarily numeric. Because it is not numeric we have to guess that in non-numeric cases you want until the end of the line. The example you give only shows one numeric value on any line but we can speculate that there might be lines with multiple numbers.

请先登录，再进行评论。