## Histogram Operations

Function: int gsl_histogram_equal_bins_p (const gsl_histogram *h1, const gsl_histogram *h2)
This function returns 1 if the all of the individual bin ranges of the two histograms are identical, and 0 otherwise.

Function: int gsl_histogram_add (gsl_histogram *h1, const gsl_histogram *h2)
This function adds the contents of the bins in histogram h2 to the corresponding bins of histogram h1, i.e. @math{h'_1(i) = h_1(i) + h_2(i)}. The two histograms must have identical bin ranges.

Function: int gsl_histogram_sub (gsl_histogram *h1, const gsl_histogram *h2)
This function subtracts the contents of the bins in histogram h2 from the corresponding bins of histogram h1, i.e. @math{h'_1(i) = h_1(i) - h_2(i)}. The two histograms must have identical bin ranges.

Function: int gsl_histogram_mul (gsl_histogram *h1, const gsl_histogram *h2)
This function multiplies the contents of the bins of histogram h1 by the contents of the corresponding bins in histogram h2, i.e. @math{h'_1(i) = h_1(i) * h_2(i)}. The two histograms must have identical bin ranges.

Function: int gsl_histogram_div (gsl_histogram *h1, const gsl_histogram *h2)
This function divides the contents of the bins of histogram h1 by the contents of the corresponding bins in histogram h2, i.e. @math{h'_1(i) = h_1(i) / h_2(i)}. The two histograms must have identical bin ranges.

Function: int gsl_histogram_scale (gsl_histogram *h, double scale)
This function multiplies the contents of the bins of histogram h by the constant scale, i.e. @c{$h'_1(i) = h_1(i) * \hbox{\it scale}$} @math{h'_1(i) = h_1(i) * scale}.

Function: int gsl_histogram_shift (gsl_histogram *h, double offset)
This function shifts the contents of the bins of histogram h by the constant offset, i.e. @c{$h'_1(i) = h_1(i) + \hbox{\it offset}$} @math{h'_1(i) = h_1(i) + offset}.