在MATLAB中的textscan：读取NULL值为NaN [英] textscan in MATLAB: read NULL value as NaN

问题描述

我有一个.txt文件，包含以下数据：
$ b

sampleF.txt - >（制表符分隔）

I have a .txt file with the following data:

MSFT    200    100
APPL    10    NULL
AMZN    20    40

我需要使用 textscan 读取这些数据。我在阅读 NULL 数据时遇到问题。使用 treatasempty param，我可以将其读为0.但是我想把它读作 NaN 。请帮忙！谢谢！

I need to read this data using textscan. I am facing a problem while reading the NULL data. Using treatasempty param, I can read it as 0. But I want to read it as NaN. Please help! Thanks!

fName = '.....\sampleF.txt'
[fid, message] = fopen(fName) ;
if fid < 0, disp(message), else
    datatxt = textscan(fid, '%q %d %d', 'Delimiter', '\t','treatAsEmpty','NULL');
    datatxt = [ datatxt {1} num2cell(datatxt {2}) num2cell(datatxt {3})] ;
    fclose(fid) ; 
end

%datatxt = { 'MSFT' [200] [100] ; 'AAPL' [10] [NaN] ; 'AMZN' [20] [40] } 

推荐答案

问题在于类型 int32 不支持NaN值。而是把数字看作双打。即：

The problem is the fact that the type int32 does not support NaN values. Instead read the numbers as doubles. ie:

data = textscan(fid, '%s %f %f', 'Delimiter','\t', ...
           'treatAsEmpty','NULL', 'EmptyValue',NaN);

这篇关于在MATLAB中的textscan：读取NULL值为NaN的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！