Read numbers and characters

Question

Patrícia Falcão 2018-8-9

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/414194-read-numbers-and-characters

评论： Stephen23 2018-8-13

采纳的回答： Stephen23

channel3txt.txt

在 MATLAB Online 中打开

Hi!

I am trying to read an output from a software that gives me numbers and semicolons, commas, minus and points. The output can be either an excel file ou txt file. If I choose the excel file and open it in matlab, the output is like this:

 1
9
.
3
1
2
5
COMMA
2
5
.
1
2
5
0
COMMA
-
1
3
.
7

But I want to matlab recognize if it is a number or a character. In reality, what I want to do is to have "19.3125, 25.1250, -13.7,..." and for that I need matlab to recognize what is a number and not. Can you help me?

5 个评论
显示 3更早的评论隐藏 3更早的评论

Stephen23 2018-8-9

编辑：Stephen23 2018-8-9

'COMMA means ","'

Sure, we know what "comma" means. But which of these is actually in the text file?:

,
COMMA

This would be much simpler if you just uploaded a sample text file by clicking on the paperclip button.

Patrícia Falcão 2018-8-9

channel3txt.txt

You're right. It is uploaded the txt file. But I don't want the first numbers, just the next to the first comma. What I have already explained to Stephen Cobeldick.

请先登录，再进行评论。

请先登录，再回答此问题。

Answer 1

Stephen23 2018-8-9

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/414194-read-numbers-and-characters#answer_332129

编辑：Stephen23 2018-8-9

在 MATLAB Online 中打开

temp0.txt

Using a simple text file (this will be much easier than processing an Excel file):

>> str = fileread('temp0.txt');
>> str = regexprep(str,'\s+','');
>> vec = sscanf(str,'%fCOMMA',[1,Inf])
vec =
   19.312   25.125  -13.700

The test file is attached. If you had actually uploaded your file then I could have tested my code on that: no sample data means I have to invent my own data, which may or may not be the same as what you have.

4 个评论
显示 2更早的评论隐藏 2更早的评论

Patrícia Falcão 2018-8-9

在 MATLAB Online 中打开

That works perfectly! The only problem is that the output in txt file is another one:

%
Time [s],Value,Parity Error,Framing Error
050669000000000,1,,
050754000000000,9,,
050840000000000,.,,
050925000000000,3,,
051010000000000,1,,
051095000000000,2,,
051180000000000,5,,
051265000000000,COMMA,,
051350000000000,2,,
051435000000000,5,,
051520000000000,.,,
051605000000000,1,,
051690000000000,2,,
051775000000000,5,,
051860000000000,0,,
051945000000000,COMMA,,
052030000000000,1,,
052115000000000,3,,
052200000000000,.,,
052285000000000,7,,
052370000000000,5,,
052455000000000,0,,
052540000000000,0,,
052625000000000,COMMA,,
052710000000000,3,,
052795000000000,9,,
052880000000000,.,,
052965000000000,8,,
053050000000000,7,,
053135000000000,5,,
053220000000000,0,,
053305000000000,COMMA,,
053390000000000,0,,
053475000000000,.,,
053560000000000,8,,
053645000000000,1,,
053730000000000,2,,
053815000000000,5,,
053900000000000,COMMA,,
053985000000000,-,,
054070000000000,1,,
054155000000000,.,,
054240000000000,5,,
054325000000000,6,,
054410000000000,2,,
054495000000000,5,,
054580000000000,;,,
054665000000000,\r,,
054750000000000,\n,,
156414000000000,1,,
156499000000000,9,,
156584000000000,.,,
156669000000000,3,,
156754000000000,1,,
156839000000000,2,,
156924000000000,5,,
157009000000000,COMMA,,

I don't want the first number (time), I just want the next char/number next to the first comma. In this case, my final goal is to have something like that: 19.3125, 25.1250, 13.7500, 39.8750, 0.8125, -1.5625; (then a new line) 19.3125, ...

Stephen23 2018-8-9

编辑：Stephen23 2018-8-9

在 MATLAB Online 中打开

channel3txt.txt

You can read the second column of that text file like this:

>> fmt = '%*s%s%*[^\n]'; % keep only second column.
>> opt =  {'Delimiter',',','HeaderLines',1};
>> [fid,msg] = fopen('channel3txt.txt','rt');
>> assert(fid>=3,msg)
>> C = textscan(fid,fmt,opt{:}); % read file data into MATLAB
>> fclose(fid);
>> C = strrep(C{1},'COMMA',','); % replace COMMA -> ,
>> str = sprintf([C{:}]) % convert to char vector, and \r\n -> to newline characters.
str = 19.3125,25.1250,13.7500,39.8750,0.8125,-1.5625;
19.3125,25.1250,13.7500,39.8750,0.8125,-1.5625;
19.3125,25.1250,13.7500,39.8750,0.8125,-1.5625;
19.3125,25.1250,13.7500,39.8750,0.8125,-1.5625;
19.3125,25.1250,13.7500,39.8750,0.8125,-1.5625;
... lots of rows here
66.3125,48.6250,165.8750,138.6250,27.8125,175.7500;
57.8125,59.2500,148.1875,1.7500,18.8750,113.4375;
50.0625,62.0000,96.2500,347.9375,2.1875,60.0625;
48.1250,59.5000,92.5000,345.5625,0.6250,63.9375;
59.7500,61.1250,144.8125,2.1875,18.6250,119.5625;
69.3750,46.9375,168.6250,139.4375,21.7500,171.3750;
62.2500,51.3750,164.8750,13

Note that your sample file does not include data for the complete last row, it appears to be truncated.

At this point str is a char vector with numbers separated by commas and semi-colons with newlines. You can efficiently convert that char vector into a numeric vector using:

>> vec = sscanf(str,'%f,%f,%f,%f,%f,%f;')
vec =
31250
12500
75000
87500
81250
    -1.56250
31250
12500
... lots of rows here:
93750
62500
43750
75000
37500
25000
37500
87500
00000

At that point you need to decide what to do with the incomplete last row. One option is to ignore it, allowing you to reshape the data into this numeric matrix:

>> vec = vec(1:6*fix(numel(vec)/6)); % remove incomplete last row
>> mat = reshape(vec,6,[]).'
mat =
31250    25.12500    13.75000    39.87500     0.81250    -1.56250
31250    25.12500    13.75000    39.87500     0.81250    -1.56250
31250    25.12500    13.75000    39.87500     0.81250    -1.56250
31250    25.12500    13.75000    39.87500     0.81250    -1.56250
31250    25.12500    13.75000    39.87500     0.81250    -1.56250
31250    25.12500    13.75000    39.87500     0.81250    -1.56250
31250    25.12500    13.75000    39.87500     0.81250    -1.56250
31250    25.12500    13.75000    39.87500     0.81250    -1.56250
 ... lots of rows here
06250    62.00000    96.25000   347.93750     2.18750    60.06250
12500    59.50000    92.50000   345.56250     0.62500    63.93750
75000    61.12500   144.81250     2.18750    18.62500   119.56250
37500    46.93750   168.62500   139.43750    21.75000   171.37500

Patrícia Falcão 2018-8-13

Thank you very much Stephen Cobeldick! You helped me a lot!

Stephen23 2018-8-13

@Patrícia Falcão: I hope that it helps! Remember to accept the answer that helped you most: this give reputation points to the volunteers who help you on this forum.

请先登录，再进行评论。

Read numbers and characters

5 个评论
显示 3更早的评论隐藏 3更早的评论

采纳的回答

4 个评论
显示 2更早的评论隐藏 2更早的评论

更多回答（0 个）

另请参阅

类别

标签

Community Treasure Hunt

Read numbers and characters

5 个评论 显示 3更早的评论隐藏 3更早的评论

采纳的回答

4 个评论 显示 2更早的评论隐藏 2更早的评论

更多回答（0 个）

另请参阅

类别

标签

Community Treasure Hunt

5 个评论
显示 3更早的评论隐藏 3更早的评论

4 个评论
显示 2更早的评论隐藏 2更早的评论