def measureCanvas(nfigs, ncols_max=2, figinches=(6,4)):
    """
    @params nfigs    : (int) Total number of figures.
    @params ncols_max: (int) The number of columns.
    @params figinches: (tuple) The figure size for 1 plot.
    """
    if nfigs>=ncols_max:
        ncols=ncols_max
        nrows=(nfigs-1)//ncols_max+1
    else:
        ncols=nfigs
        nrows=1
    w,h = figinches
    figsize=(w*ncols,h*nrows)
    return (ncols, nrows, figsize)