Get corresponding row index of array to plot graph

[nikvl]

Hi all,

so I'm trying to read data from a text file, and plot them onto an XY graph.

The string text data file is built as such:

XXX;Time/Date Stamp;Data point type A;1;X

XXX;Time/Date Stamp;Data point type B;2;X

XXX;Time/Date Stamp;Data point type C;3;X

XXX;Time/Date Stamp;Data point type A;1;X

XXX;Time/Date Stamp;Data point type B;2;X

. . .

Say I want to plot only point A with the corresponding time stamp, and the data points are distinguished from each other through a number after the semicolon, in this case 1. And if I want the graph for point B I would match with 2 and so on.

How do I get the indexes of all the corresponding row that matches with 1 so that I am able to extract them along with the time stamp to plot the graph for data point A? 

I attached a snippet of the simplified version of what I have so far and it's not quite right because I'm not getting the correct plot.

Thank you in advance!

[GerdW · Accepted solution]

Hi nikvl,

after creating the arrays for timestamps and "data point" you also should create an array of "position".

Then feed all 3 arrays into a FOR loop containing a simple comparison with desired "position" value. Then use conditional output tunnels to create filtered arrays of timestamp and "data points"…

Example:

[nikvl]

I had to tweak some things and add an extra for loop but it worked wonderfully. Thanks!

Unrelated, but is there a way to make the array of time stamps into seconds starting from 0? (or should I open a new thread for that?)

[GerdW]

Hi nikvl,

---

@nikvl wrote:

Unrelated, but is there a way to make the array of time stamps into seconds starting from 0?

---

Simple math:

Relative time := absolute time - start time

So just subtract start time from your timestamp array…

[nikvl]

I figured, but it skewed the display and the year became 1904. Maybe I'm not setting the start time properly since I used an index array with index 0 (when the index should be at what row the desired data point first appears) 

If possible, I'd like to display in seconds without the year like 0, 1 , 2, ....

[GerdW · Accepted solution]

Hi nikvl,

set the format to relative time…