title: What is the R equivalent to Python's `sns.heatmap(DATANAME.isnull(),cbar=False,cmap='viridis')`?
body: <p>What is the R equivalent to Python's <code>sns.heatmap(DATANAME.isnull(),cbar=False,cmap='viridis')</code>? I'd like to make a seaborn style headmap to visualize missing values, but I am using R instead of Python. Thanks!</p>