function setDataminRange(plot, axis) {
        if (axis.options.mode === 'log' && axis.datamin <= 0) {
            if (axis.datamin === null) {
                axis.datamin = 0.1;
            } else {
                axis.datamin = processAxisOffset(plot, axis);
            }
        }
    }
- setDataminRange(plot, axis)

    It is used for clamping the starting point of a logarithmic axis.
    This will set the axis datamin range to 0.1 or to the first datapoint greater then 0.
    The function is usefull since the logarithmic representation can not show
    values less than or equal to 0.