plot single column binary file with gnuplot

Question

how can I plot single column binary file with gnuplot?

This is the gnuplot command I am using:

plot "file.bin" binary format="%float" u ($0+1):1 every ::0::999

but I get all the points along the vertical line x = 0.

I am creatiing the binary file in a C code I have:

write(fdesc, bin_data, tot_size * sizeof(double));

Thanks.

Answer 1

If you write double values to the binary file, you must also read doubles from gnuplot:

plot "file.bin" binary format="%double" u 0:1 every ::::999

As a more complete example, consider the following C snippet simple.c:

#include <unistd.h>    
int main(int argc, char* argv[])
{
    const int N = 128;
    double values[N];
    int i;
    for (i = 0; i < N; i++)
    values[i] = i * i;

    write(STDOUT_FILENO, values, N*sizeof(double));
}

Compile that with gcc simple.c, open gnuplot and type

plot '< ./a.out' binary format='%double' using 0:1