Problems with doubles

This is a discussion on Problems with doubles within the C++ Programming forums, part of the General Programming Boards category; Hi, I am making a algorithm that is very important the value of the numbers, but I have some problems, ...

  1. #1
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    Problems with doubles

    Hi, I am making a algorithm that is very important the value of the numbers, but I have some problems, for example I need to do this operation: 1.0/14709204.0, after for I know the result of the operation I write the result of operation in one file, for example I do this:
    Code:
    FILE* tot = fopen("total.txt", "wb");
    char buffft [2000];
    sprintf (buffft,"%f",1/14709204);
    fwrite(buffft,1,strlen(buffft),tot);
    After I open the file total.txt I can see 0.000000, and the correct result is :6.798464417*10-8, I need this result, can someone help me please?any idea?
    Thanks.

  2. #2
    Code Goddess Prelude's Avatar
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    >1/14709204
    This is an integer expression with an integer result because both operands are integers. To make it floating-point, change one or both of the values to double:
    Code:
    sprintf (buffft,"%f",1.0/14709204.0);
    My best code is written with the delete key.

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    Gracias por la respuesta, pero hago esto que usted cuenta y el resultado es el mismo: 0.000.
    ┐Alguna idea?

  4. #4
    Code Goddess Prelude's Avatar
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    Hablar por favor inglÚs.
    My best code is written with the delete key.

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    I have written it in Spanish, this one is the translation:
    Thanks for the reply, but I do this that you tell and the result is the same: 0.000.
    Any idea?

  6. #6
    Code Goddess Prelude's Avatar
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    Try the %g format modifier instead of %f.
    My best code is written with the delete key.

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    Thanks, now in the file I can see 6.79846e-008 (the correct result), Therefore now I that the result of my operations they are correct.. Therfore the problem of my algorithm are in the other part...jeje thanks for the fast replys.

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