c++ - 使用 ifstream 读取 float

Question

我正在尝试使用 ifstream 从 .out 文件中读取一系列 float ，但如果我之后输出它们，它们就不正确了。

这是我的输入代码:

float x, y, z;

ifstream table;
table.open("Resources/bones.out");
if (table.fail())
{
    cout << "Can't open table" << endl;
    return ;
}

table >> x;
table >> y;
table >> z;

cout << x << " " << y << " " << z << endl;

table.close();

我的输入文件:

0.488454 0.510216 0.466979
0.487242 0.421347 0.472977
0.486773 0.371251 0.473103
...

现在进行测试，我只是将第一行读入 x y 和 z，我的输出是

1 0 2

关于为什么我没有得到正确的输出有什么想法吗？

Answer 1

#include <fstream>
#include <strtk.hpp>   // http://www.partow.net/programming/strtk

std::string filename("Resources/bones.out");

// assuming the file is text
std::fstream fs;
fs.open(filename.c_str(), std::ios::in);

if(fs.fail())  return false;   

const char *whitespace    = " \t\r\n\f";

std::string line;
std::vector<float> floats;
std::vector<std::string> strings;
float x = 0.0, y = 0.0, z = 0.0;
std::string xs, ys, zs;

// process each line in turn
while( std::getline(fs, line ) )
{
    // Removing beginning and ending whitespace
    // can prevent parsing problems from different line endings.
    // formerly accomplished with boost::algorithm::trim(line)

    strtk::remove_leading_trailing(whitespace, line);


    // strtk::parse combines multiple delimiters in these cases

    if( strtk::parse(line, whitespace, floats ) ) 
    {
         std::cout << "succeed" << std::endl;
         // floats contains all the values on the in as floats
    }

    if( strtk::parse(line, whitespace, strings) ) 
    {
         std::cout << "succeed" << std::endl;
         // strings contains all the values on the in line as strings
    }

    if( strtk::parse(line, whitespace, x, y, z) ) 
    {
         std::cout << "succeed" << std::endl;
         // x,y,z contain the float values.  parse fails if more than 3 floats are on the line
    }

    if( strtk::parse(line, whitespace, xs, ys, zs) ) 
    {
         std::cout << "succeed" << std::endl;
         // xs,ys,zs contain the strings.  parse fails if more than 3 strings are on the line
    }
}

我就是这样解决的。您可以选择自己的方式来解析数据。