Finding the time stamp in a time wave

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Wed, 05/30/2018 - 11:10 am

Hello,

I am relatively new to Igor use. I am trying to process a large amount of data stored in a file in csv format with a time stamp. So, I am able to load the data using loadwave command into two different waves, one containing the time stamp, and the other is the value of the quantity I am measuring at that time. Now, I want to locate the point closest to my time of interest in the time wave. Could you help me finding the syntax for it? For example:

The time wave looks like: 10:23:34 am, 10:23:38 am, 10:23:42 am. If I want to find the point corresponding to the time 10:23:38 am, what syntax or command do I need to use.

Thank you,
Vikram
Time of day is stored as seconds since midnight.

[ Date/time is stored as seconds since midnight on 1904-01-01. For details, execute:
 DisplayHelpTopic "Date/Time Waves"
]

Here is an example that may help:
// Examples:
//      Demo(10, 23, 38)
//      Demo(10, 23, 40)
Function Demo(hours, minutes, seconds)
    Variable hours, minutes, seconds        // The time of day to search for

    Variable timeOfDayToSearchFor = hours*3600 + minutes*60 + seconds   // Convert to seconds since midnight

    Variable t0 = 10*3600 + 23*60 + 34      // 10:23:34 AM as seconds since midnight
    Variable t1 = 10*3600 + 23*60 + 38      // 10:23:38 AM
    Variable t2 = 10*3600 + 23*60 + 42      // 10:23:42 AM
    Make/O timeOfDayWave = {t0, t1, t2}
   
    FindLevel/P/Q timeOfDayWave, timeOfDayToSearchFor       // Stores fractional point number in V_LevelX
    Printf "Point number is %g\r", V_LevelX
End

May 30, 2018 at 12:43 pm - Permalink