def plot_evec(fignum, Vs, symsize, title):
    """
    plots eigenvector directions of S vectors

    Paramters
    ________
    fignum : matplotlib figure number
    Vs : nested list of eigenvectors
    symsize : size in pts for symbol
    title : title for plot
    """
#
    plt.figure(num=fignum)
    plt.text(-1.1, 1.15, title)
    # plot V1s as squares, V2s as triangles and V3s as circles
    symb, symkey = ['s', 'v', 'o'], 0
    col = ['r', 'b', 'k']  # plot V1s rec, V2s blue, V3s black
    for VEC in range(3):
        X, Y = [], []
        for Vdirs in Vs:
            #
            #
            #   plot the V1 data  first
            #
            XY = pmag.dimap(Vdirs[VEC][0], Vdirs[VEC][1])
            X.append(XY[0])
            Y.append(XY[1])
        plt.scatter(X, Y, s=symsize,
                    marker=symb[VEC], c=col[VEC], edgecolors='none')
    plt.axis("equal")
plots eigenvector directions of S vectors

    Paramters
    ________
    fignum : matplotlib figure number
    Vs : nested list of eigenvectors
    symsize : size in pts for symbol
    title : title for plot