Converting a Waveform to a 2D Array

• My data is in a waveform and I would like to convert it to a two-dimensional (2D) array of doubles
• I need to write waveform data to a text file
• I would like to use array functions on my waveform data

• In order to convert this data to a 2D array, you will need to extract the existing Y data from the waveform and assign a time to each value
• Below is an example of how to convert the data into a 2D array of doubles
  1. Use the Get Waveform Components function to extract the Y and dt data from the waveform
  2. Auto-index via a For Loop to get the array of Y values
  3. Within the loop multiply dt by the iteration count. This will give the time associated with each data point
  4. Combine the Y array and the output of the multiplication by using the Build Array function
  5. The indexed output from the Build Array function will give you a 2D array of the waveform data relative to time

Additional Information

• The waveform data type is a special type of cluster made up of 4 elements
  • Y - This is a 1D Array of the amplitude measurements of your data
  • t0 - This is a time stamp signifying the start time of your measurement
  • dt - This is a scalar that describes the uniform time division of the signal in seconds
  • Attributes - This is a variant data type containing all of the waveform metadata, such as the hardware device number or the channel names
• The snippet above and this community example show an implementation of the desired program
• The method above is completely ignoring the attributes and t0 data elements from the waveform and only focusing on the time division (dt) and amplitude data (Y).
  • This simplifies the code and focuses on the most important elements of the incoming data.
• The code in the snippet above does the following
  • Takes the amplitude array and iterates through the array, assigning a time value of the time division multiplied by the current iteration of the loop
  • By first combining these two values into a two element 1D array and then indexing it with a for loop, the result is a 2D array of two columns
  • The first column contains time information, starting at 0, increasing by dt every row
  • The second column contains all of the amplitude data.
  • Note that additional waveform functions can be found in the functions palette under Programming » Waveform.