Separate XY Pair into Weekday and Weekend Waves

// Demo showing how to split XY waves into weekday and weekend waves
 
//  DayOfWeek(dt)
//  Returns day of week as a number from 1 (Sunday) to 7 (Saturday)
Function DayOfWeek(dt)
    Variable dt                 // Input date/time value
 
    String shortDateStr = Secs2Date(dt, -1)     // <day-of-month>/<month>/<year> (<day of week>)
    
    Variable dayOfMonth, month, year, dayOfWeek
    sscanf shortDateStr, "%d/%d/%d (%d)", dayOfMonth, month, year, dayOfWeek
    
    return dayOfWeek    
End
 
// IsWeekday(dt)
// Returns 0 for Saturday and Sunday, 1 for the rest of the week
Function IsWeekday(dt)
    Variable dt                 // Input date/time value
 
    Variable day = DayOfWeek(dt)
    if (day == 1)
        return 0                // Sunday
    endif
    if (day == 7)
        return 0                // Saturday
    endif
    return 1
End
 
Function Demo() // Demonstrates separating an XY pair into weekday and weekend data
    // Make XY pair with date/time values for X
    Make/D/O/N=1000 xData = Date2Secs(2014, 01, 01) + p*60*60       // Step by one hour
    SetScale d, 0, 0, "dat", xData
    Make/D/O/N=1000 yData = p
    
    // Split into weekday and weekend data
    Extract xData, xDataWeekday, IsWeekday(xData)
    SetScale d, 0, 0, "dat", xDataWeekday               // Extract does not preserve units
    Extract yData, yDataWeekday, IsWeekday(xData)
    Extract xData, xDataWeekend, !IsWeekday(xData)
    SetScale d, 0, 0, "dat", xDataWeekend               // Extract does not preserve units
    Extract yData, yDataWeekend, !IsWeekday(xData)
    
    Display /W=(30,53,816,609) yData vs xData
    AppendToGraph yDataWeekday vs xDataWeekday
    ModifyGraph rgb(yDataWeekday)=(0, 0, 65535), offset(yDataWeekday)={0,100}
    AppendToGraph yDataWeekend vs xDataWeekend
    ModifyGraph rgb(yDataWeekend)=(0, 65535, 0), offset(yDataWeekend)={0,200}
    ModifyGraph mode=2, lsize=3
    Legend/C/N=text0/A=LT
End