Reducing number of values

[hmurya]

how can i loop this so it automatically reads the 13 files in a folder and appends all the files so i dont have to run them one by one

or a way in which it combines all the RMS values so i dont have 13 different files, just 1 file in proper sequence

[Brad_Turpin]

Hi hmurya,

Here's how to append-load all the TDMS files in a certain folder.  There's an append-load option to the DataFileLoad...() commands in DIAdem 2015 and later, but this set of commands will work on previous DIAdem versions as well.

DataFolder = "D:\NICS\Discussion Forums\hmurya\Data Folder\"
DataFiles = DirListGet(DataFolder, "*.tdms", "filename", "FullFilenames")
'LogFileWrite Join(DataFiles, vbCRLF)
iMax = UBound(DataFiles)
Call Data.Root.Clear
Call DataFileLoadSel(DataFiles(0), "TDMS", "[1]/[1]")
Set Group = Data.Root.ChannelGroups(1)
Set AppChannel = Group.Channels(1)
FOR i = 1 TO iMax
  Set NewChannel = DataFileLoadSel(DataFiles(i), "TDMS", "[1]/[1]")
  Call ChnConcat(NewChannel, AppChannel)
  Call Group.Channels.Remove(2)
NEXT ' i

Brad Turpin

DIAdem Product Support Engineer

National Instruments

[hmurya]

Hello.

I am running into a small problem here. I was informed experiment was run for a total of 360seconds, but when I run the script, it gives me an output of 444secs.

Can you explain the script to me and what part of it uses to measure how many data points make up a second?

[Brad_Turpin]

Hi hmurya,

I assume you're referring to the script on the first page of this Discussion Forum post, not the script immediately above your post.  The script on the first post page determines the sampling period from the waveforma property ("wf_increment"), then inverts that to determine the number of values per second (SecVals).  It then calculates the RMS value for each second by running the StatBlockCal() command over each second of values:

Delta = DatChannel.Properties("wf_increment").Value
Call ChnWfPropSet(RmsChannel, "Time", "s", (Start+1)/2, 1)
SecVals = 1/Delta
FOR i = 1 TO iMax Step SecVals

Brad Turpin

DIAdem Product Support Engineer

National Instruments

[hmurya]

ah alright.

what function would i need to use instead to calculate skewness and kurtosis the same way? Currently I am getting a single value for the whole length of the file.