在C ++中以'D'作为指数前缀读取双重科学符号 [英] Read double scientific notation with 'D' as exponent prefix in C++

问题描述

我正在尝试读取写为-0.49430978D-02的值，但它们仅以-0.49430978的形式出现.我将字符保存在字符串vs中，并且都尝试过

myval = stod(vs)

以及

sscanf(vs.c_str(), "%le", &myval)

但是他们两个都没有读懂科学计数法中的指数.是因为它是D而不是E吗?如何在c++中正确读取此值?

D格式是某些Fortran实现常见的不常见浮点表示形式，用于表示双精度(或更高精度). AFAIK，所有其他环境都将E用作浮点，并且不表示底层精度.

我认为您唯一的选择是将值读取为字符串，用E替换任何D字符，然后用strtod()或同等功能完成处理.

I am trying to read values that are written as -0.49430978D-02, but they are only coming in as -0.49430978. I have the characters saved in a string vs and have attempted both

myval = stod(vs)

as well as

sscanf(vs.c_str(), "%le", &myval)

but both of them fail to read the exponent in the scientific notation. Is it because it is D and not E? How do I read this value correctly in c++?

解决方案

The D format is an uncommon floating point representation common to some Fortran implementations to indicate double precision (or greater). AFAIK, all other environments use E for floating point and do not indicate the underlying precision.

I think your only choice is to read the value as a string, replace any D characters with E and then finish processing with strtod() or equivalent.

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