<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def plot_hist(image, threshold=0., fit_line=False, normfreq=True, ## plot label arguments title=None, grid=True, xlabel=None, ylabel=None, ## other plot arguments facecolor='green', alpha=0.75):
 """ Plot a histogram from an ANTsImage Arguments --------- image : ANTsImage image from which histogram will be created """

    img_arr = image.numpy().flatten()
    img_arr = img_arr[np.abs(img_arr) > threshold]

    if normfreq != False:
        normfreq = 1. if normfreq == True else normfreq
    n, bins, patches = plt.hist(img_arr, 50, normed=normfreq, facecolor=facecolor, alpha=alpha)

    if fit_line:
        # add a 'best fit' line
        y = mlab.normpdf( bins, img_arr.mean(), img_arr.std())
        l = plt.plot(bins, y, 'r--', linewidth=1)

    if xlabel is not None:
        plt.xlabel(xlabel)
    if ylabel is not None:
        plt.ylabel(ylabel)
    if title is not None:
        plt.title(title)

    plt.grid(grid)
    plt.show()