error

This is a discussion on error within the C Programming forums, part of the General Programming Boards category; the instructions for this program is to use newton method to find zeros of a cubic function. cubics.h is given ...

  1. #1
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    error

    the instructions for this program is to use newton method to find zeros of a cubic function. cubics.h is given and it includes function prototypes and we have to write four functions on cubics.c. findroot.c has the main function and includes cubics.c and cubics.h. when compiling it, i get the error:



    they say:
    cubics.o (.text+0x68): In function 'cubic': multiple definition of
    'cubic'
    findroot.o(.text+068): first defined here

    and then it does the same for the rest of the four functions in cubics.c,
    but
    at the end it says

    collect2:ld returned 1 exit status

    any ideas on whats wrong?

  2. #2
    Registered User Micko's Avatar
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    Post code so we can see where multiple definition occur. You must know that in C multiple declaration is allowed but multiple definition isn't

  3. #3
    ATH0 quzah's Avatar
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    Sounds like you've got multiple declarations of 'cubic' to me. Perhaps one in 'cubics.c' and another in 'findroot.c', but that's just a wild guess...

    On a related note, if this is true:
    and includes cubics.c and cubics.h.
    Then stop #include-ing 'cubics.c' and try just compiling it and linking it instead.

    Quzah.
    Hope is the first step on the road to disappointment.

  4. #4
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    well our professor gave us the makefile but i think i have multiple definitions of cubics.c, ill check it out now

  5. #5
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    findroot includes cubics.c and findroot.c, cubics.c inclues cubics.h but cubics.h has the #ifdef

  6. #6
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    sorry, i meant findroot.c includes cubics.h and cubics.c and cubics.c includes cubics.h

  7. #7
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    >findroot.c includes cubics.h and cubics.c
    There's your problem. You don't need to include cubics.c here.

  8. #8
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    yea that was it! thanks

  9. #9
    ATH0 quzah's Avatar
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    So kind of like I said in the first reply. No, make that exactly like I said.

    Quzah.
    Hope is the first step on the road to disappointment.

  10. #10
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    Quote Originally Posted by quzah
    So kind of like I said in the first reply. No, make that exactly like I said.

    Quzah.
    And twelve hours later, the lightbulb turns on.

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