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POPointer in struct question. Have I done it correct?
 

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  1. POPointer in struct question. Have I done it correct?
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    <p>I am rewriting some code from having a regular pointer to where the pointer is in a struct.</p> <p>This is the original code which works:</p> <pre><code>int wrote = sf_writef_double(outfile, *mono_channel, frames); </code></pre> <p>In the new code, where I have put the mono_channel pointer in a struct have I written</p> <pre><code>int wrote = sf_writef_double(outfile, data-&gt;mono_channel, frames); </code></pre> <p>The compiler doesn't complain, but the program crashes.</p> <p>So the question is. Is <code>data-&gt;mono_channel</code> the same as <code>*mono_channel</code>?</p> <p>Hugs, Louise</p> <p><strong>Edit:</strong> To be more precise here is what I do:</p> <pre><code>ltfat_complex* fm; fm = malloc(data-&gt;L * sizeof(ltfat_complex)); if (fm == NULL) { puts("fm malloc failed"); exit(1); } /* Writes output to fm */ idgt_fac(data-&gt;coef, gdf, data-&gt;L, 1, 1, data-&gt;a, data-&gt;M, fm); free(data-&gt;mono_channel); data-&gt;mono_channel = (double*) fm; free(fm); </code></pre> <p>...</p> <pre><code>int wrote = sf_writef_double(outfile_handler, data-&gt;mono_channel, frames); </code></pre> <p>Could the problem be, that I try to re-use the <code>data-&gt;mono_channel</code> pointer?</p> <p><strong>Edit2:</strong> Here are the entire source codes (~ 700 lines each):</p> <p>Old which works: <a href="http://www.student.dtu.dk/~s011392/gabor-io.zip" rel="nofollow noreferrer">http://www.student.dtu.dk/~s011392/gabor-io.zip</a></p> <p>New: <a href="http://www.student.dtu.dk/~s011392/gui.zip" rel="nofollow noreferrer">http://www.student.dtu.dk/~s011392/gui.zip</a></p> <p>Sadly they require a lot of libraries to compile: ltfat from SVN, fftw3, lapack, blas, sndfile.</p> <p>But there tey are =)</p>
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    1. COThe problem here is `free(fm)`. That also frees `data->mono_channel`, so you can't use it later.
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      1. USChris Lutz
    2. COWOW! You are right. That fixed it =) Thanks a lot! I had spend all night looking at that. I am new here at Stack Overflow. Can I give you points?
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      1. USLouise
    3. COUnfortunately, there's no way to give points for a comment. And he already has the only badge that you can get for making good comments.
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      1. USMichael Myers
 

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