Abiel questions

• data.table group by with a filter condition [duplicate]
• Invert Y axis in Highcharts
• Using VBA to put a chart series on the secondary X axis
• Date axis labeling algorithm for Excel
• Get Excel.Application object from Process or hwnd in .NET
• Performance difference between RcppArmadillo and Armadillo
• Construct Numpy index given list of starting and ending positions
• Force axis to use given number of major tick marks in Visiblox chart
• Pass argument to data.table aggregation function
• Get name of active Excel workbook from Python

Abiel answers